*Article* **Home Cooking and Child Obesity in Japan: Results from the A-CHILD Study**

#### **Yukako Tani, Takeo Fujiwara \*, Satomi Doi and Aya Isumi**

Department of Global Health Promotion, Tokyo Medical and Dental University (TMDU), 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan<EMAIL_ADDRESS>(Y.T<EMAIL_ADDRESS>(S.D<EMAIL_ADDRESS>(A.I.)

**\*** Correspondence<EMAIL_ADDRESS>Tel.: +81-3-5803-5187; Fax: +81-3-5803-5190

Received: 1 October 2019; Accepted: 19 November 2019; Published: 21 November 2019

**Abstract:** This study aimed to investigate the association between the frequency of home cooking and obesity among children in Japan. We used cross-sectional data from the Adachi Child Health Impact of Living Difficulty study, a population-based sample targeting all fourth-grade students aged 9 to 10 in Adachi City, Tokyo, Japan. Frequency of home cooking was assessed by a questionnaire for 4258 caregivers and classified as high (almost every day), medium (4–5 days/week), or low (≤3 days/week). School health checkup data on height and weight were used to calculate body mass index *z*-scores. Overall, 2.4% and 10.8% of children were exposed to low and medium frequencies of home cooking, respectively. After adjusting for confounding factors, children with a low frequency of home cooking were 2.27 times (95% confidence interval: 1.16–4.45) more likely to be obese, compared with those with a high frequency of home cooking. After adjustment for children's obesity-related eating behaviors (frequency of vegetable and breakfast intake and snacking habits) as potential mediating factors, the relative risk ratio of obesity became statistically non-significant (1.90; 95% confidence interval: 0.95–3.82). A low frequency of home cooking is associated with obesity among children in Japan, and this link may be explained by unhealthy eating behaviors.

**Keywords:** home cooking; meal preparation; obesity; children; parenting

#### **1. Introduction**

The prevalence of childhood overweight and obesity has increased worldwide in recent decades, becoming a major public health epidemic [1]. In Organization for Economic Cooperation and Development (OECD) countries, the prevalence of childhood overweight and obesity is 25% [2]. Obese children are more likely to become obese adults [3] and are at a higher risk of a wide range of serious health complications [4]. To combat the obesity epidemic, it is important that prevention efforts are shaped by a solid evidence base regarding the risk factors for obesity in children.

Home cooking has been suggested as a key strategy to prevent obesity [5]. In developed countries, sociodemographic changes, such as an increasing numbers of working women and single-parent or small families, have led to less time being available for home cooking and an increased shift toward eating out or buying prepared meals [6–8]. In Japan, household expenditure for prepared food has increased in recent decades, and eating out is common among younger age groups [9]. Increased consumption of out-of-home foods, such as fast food and convenience food, is a major concern because these foods are higher in calories, fat, and sodium; lower in fiber and calcium [10–13]; and associated with poor diet quality and increased energy intake among children [12–15]. Several studies conducted in the United States have shown an association between fast food consumption and increased weight gain in adolescents [16,17]. However, these studies evaluated only the effect of eating out; they did not examine the effect of at-home consumption of prepared (precooked) meals, such as packed lunches, convenience foods, and ready-made meals. To account for the effects of both eating out and eating prepared meals at home, it is necessary to examine the frequency of home cooking.

Several studies of adults have suggested that home cooking improves diet quality and weight status [18–20]. However, there is limited evidence on the relationship between home cooking and children's weight status. Parents who report a low enjoyment of cooking, little meal planning, and fewer hours spent on food preparation are less likely to serve vegetable and fruits, whereas they are more likely to serve fast food for family dinners [21]. Furthermore, because children may model their parents' healthy eating habits, enjoy meal time more, and feel closer to their caregivers through having home-cooked meals, home cooking may be beneficial for healthy child development, including weight status, because it fosters a better relationship between the caregiver and the child [22–26]. Moreover, because dietary intake patterns established early in life tend to persist into adolescence and adulthood [27–29], it is also important to understand the associations between home-cooking habits and child weight status. Children who eat less home-cooked food may be vulnerable to the development of unhealthy dietary behaviors, which may, in turn, be linked to obesity. However, to the best of our knowledge, no studies have been conducted to examine the association between home cooking and child obesity in Japan.

The purpose of the present study was to examine the association between the frequency of home cooking and obesity among children in Japan.

#### **2. Materials and Methods**

#### *2.1. Study Design and Subjects*

The Adachi Child Health Impact of Living Difficulty (A-CHILD) project was established in 2015 to evaluate the determinants of health among children in Adachi City, Tokyo, Japan [30–32]. We used data from the 2018 wave of the A-CHILD study. The survey covered all 69 public elementary schools established in Adachi City, Tokyo, Japan. In 2018, self-reported questionnaires with anonymous unique identification numbers were distributed to 5311 children in the fourth grade (aged 9–10 years) in these elementary schools. The children were asked to pass on the questionnaires to their caregivers at home to complete. The children then returned the completed questionnaires to their schools. A total of 4605 caregivers completed the questionnaires (response rate: 86.7%), and 4290 provided informed consent and returned all the questionnaires. To examine child body mass index (BMI), we used school health checkup data on body height and weight, collected in April or May 2018, which was linked to the questionnaire responses using the anonymous unique identification number. Participants who did not indicate their body height, weight status, or month of birth (*n* = 20) were excluded from the analysis, as were participants who did not complete the questions related to home-cooking status (*n* = 12). After these exclusions, 4258 participants were included in the study. The final sample comprised information on 2151 boys and 2107 girls. Of the caregivers who completed the questionnaires, 91.5% were mothers and 7.7% were fathers. The A-CHILD protocol and the use of the data in this study were approved by the Ethics Committee at Tokyo Medical and Dental University (No. M2016-284).

#### *2.2. Child Body Height and Weight Status*

School teachers assessed child height and weight at elementary schools during a school health checkup, following a standardized protocol [33]. Height was measured to the nearest 0.1 cm using a portable stadiometer, and weight was measured to the nearest 0.1 kg on a digital scale, without shoes and in light clothing. BMI was calculated by dividing the child's weight (in kilograms) by the square of body height (in meters). BMI was expressed as a *z*-score representing the deviation in standard deviation units from the mean of a standard normal distribution of BMI specific to age and sex, according to the World Health Organization's Child Growth Standards. Children's BMIs were categorized as underweight/normal weight (<+1 SD), overweight (≥+1 SD and <+2 SD), or obese (≥+2 SD) using standard deviation cut-off points [34].

#### *2.3. Home-Cooking Frequency*

Following previous studies [35,36], home-cooking frequency over the past month was assessed using the following question: "How many times did you or someone else in your family cook meals at home? Include a simple meal, such as fried eggs, as a cooked meal". The five response categories were almost every day, 4–5 days/week, 2–3 days/week, a few days/month, and rarely. Considering the distribution of the answers to this question and based on categories previously used in other studies [35,36], we collapsed the responses into three groups of frequency of home cooking: (i) High (almost every day: 86.8%); (ii) medium (4–5 days/week: 10.8%); and (iii) low (≤3 days/week: 2.4%).

#### *2.4. Covariates*

Possible covariates, such as children's physical activity and eating behaviors, were also assessed using the caregiver-completed questionnaires. Children's physical activity was assessed using the frequency of physical activity for 30 min or more during the week (never/rarely, 1–2 times/week, 3–4 times/week, or ≥5 times/week). Children's eating behavior included frequency of vegetable intake (twice/day, once/day, or <3 times/week), frequency of breakfast intake (every day, often, or rarely/never), and snacking habits (no snacking, snacking at a set time (controlled), or snacking freely) [32]. Household characteristics included the caregiver's marital status (married or living with partner, single, divorced, or widowed), the child having siblings (yes or no), cohabitation with the child's grandparents (yes or no), and annual household income (<3.00, 3.00–5.99, 6.00–9.99, or ≥10.0 million yen). Caregiver characteristics included mother's age (<35, 35–44, or ≥45 years), mother's educational attainment (low (junior high school, dropped out of high school, or completed high school), middle (professional school, some college, or dropped out of college), or high (completed college or more), mother's employment and time of returning home from work (employed/returning home before 18:00, employed/returning home 18:00–20:00, employed/returning home after 20:00, employed/returning home at irregular times, or not employed), and mother's and father's BMIs calculated using self-reported height in centimeters and weight in kilograms. Standard categories of BMI [37] were used to characterize parents as obese (BMI <sup>≥</sup> 30.0 kg/m2), overweight (BMI = 25.0–29.9 kg/m2), normal weight (BMI = 18.5–24.9 kg/m2), or underweight (BMI < 18.5 kg/m2).

#### *2.5. Statistical Analysis*

First, the participants' characteristics were stratified by home-cooking status, and differences were tested using Pearson's chi-square test. Second, we calculated relative risk ratios (RRRs) and 95% confidence intervals (CIs) of overweight and obesity using multinomial logistic regression. Two models were constructed for both overweight and obesity. Model 1 adjusted for child's sex, physical activity, household characteristics (marital status, having siblings, living with grandparents, and household income), and caregiver characteristics (mother's age, education, employment, and BMI and father's BMI) as potential confounders. Model 2 additionally adjusted for the child's obesity-related eating behaviors (frequency of vegetable intake, frequency of breakfast consumption, and snacking habits) as potential mediating factors because children may learn to model their eating behaviors based on their caregivers through home cooking, which may affect children's weight status.

#### **3. Results**

The majority of the caregivers cooked at home for their children almost every day (86.8%), whereas 2.4% of the caregivers cooked at home less often than 3 days per week and 10.8% cooked at home 4 to 5 days per week. The breakdown of the distribution of cooking at home less often than 3 days per week was 1.8% for 2 to 3 days/week, 0.5% for a few days/month, and 0.1% for rarely. Overall, 14.7% of the children were overweight, and 5.9% were obese (Table 1). In terms of household status, 72.8% of the caregivers were married, 80.5% of the children had siblings, 10.2% lived with the child's grandparents, and 10.7% were poor households with annual incomes of less than three million yen. (Table 2) The

most common maternal education level was professional school, some college, or dropped out of college. In 21% of the households, the mothers returned home from work after 18:00 or irregularly. When the mothers did not work or returned home from work before 18:00, the frequency of home cooking was high. The frequency of home cooking was low in households with a non-married parent and in those with low income. Children exposed to a low frequency of home cooking tended to have lower frequencies of vegetable and breakfast intake and snacked freely (Table 1).

**Table 1.** Characteristics of participating children (*n* = 4258).

BMI: body mass index; SD: standard deviation.

BMI: body mass index.

After adjusting for potential confounding factors, children who were exposed to a low frequency (≤3 days/week) of home cooking were 2.27 times (95% CI: 1.16–4.45) more likely to be obese, compared with children who were exposed to home cooking almost every day (Table 3, Model 1). After adjustment for children's obesity-related eating behaviors as potential mediators, this RRR was reduced and became statistically non-significant (*RRR* = 1.90; 95% CI: 0.95–3.82) (Table 3, Model 2).

**Table 3.** Adjusted relative risk ratios of overweight and obesity according to the frequency of home cooking among school children in Japan (*n* = 4258).

RRR: relative risk ratio; CI: confidence interval; ref: reference. Boldface indicates statistical significance (*p* < 0.05). Model 1 adjusted for child's sex, physical activity, household status (parents' marital status, siblings, living with grandparents, and household income), and caregiver's status (mother's age, education, employment, and BMI and father's BMI). Model 2 adjusted for child's eating behaviors (frequency of vegetable and breakfast intake and snacking habits), as well as all variables in Model 1.

#### **4. Discussion**

To our knowledge, this is the first study to examine the association between the frequency of home cooking and obesity among children aged 9 to 10 years. We found that a low frequency (<3 days per week) of home cooking doubled the risk of obesity for children, even after controlling for child's sex, physical activity, household characteristics (parents' marital status, siblings, living with grandparents, and household income), and parents' individual characteristics (maternal age, education, and employment, and BMI for both parents). This association was attenuated after controlling for potential mediating factors (i.e., child's obesity-related eating behaviors), suggesting that children's eating behaviors partially mediated the association between home cooking and children's obesity.

Three possible factors may explain the link between less frequent home cooking and child obesity: (i) Caregivers' food choices; (ii) healthy eating practices; and (iii) children eating similar foods to those eaten by their caregivers. These potential mechanisms could play a role in determining whether the association between home cooking and obesity in children is direct (i.e., home cooking is directly associated with child obesity) or indirect (i.e., home cooking influences children's eating behavior, which, in turn, is associated with child obesity). We found that the association between home cooking and the child's obesity became non-significant after adjusting for the child's frequency of vegetable and breakfast intake and snacking habits in Model 2. This finding may be explained by the caregiver's food choice: Caregivers who usually cook at home may be more likely to select healthier foods, compared with caregivers who provide out-of-home food. Consistent with this idea, a previous study found that home cooking was associated with higher vegetable consumption among children [38]. Two other studies demonstrated that, among adults, a higher frequency of home-cooked meals was associated with indicators of a healthier diet, including fruit and vegetable intake, Mediterranean diet score, and Dietary Approaches to Stop Hypertension (DASH) score [20,39]. Compared with food prepared at home, food prepared outside of the home is higher in calories as well as total and saturated fats and has less fiber, calcium, and iron [10]. Alexy et al. argued that convenience foods have a high fat content and contain many flavorings and food additives [12]. Previous research has suggested that the presence of children in the household might be protective for family body weight: Sobal et al. reported an inverse association between the frequency of family meals and body weight for adults with children at home, but no such association was found among adults without children [40]. These results may indicate that cooking at home with children is beneficial for creating a healthy food environment.

A second explanation is that the frequency of home cooking may be a proxy for caregivers' healthy eating practices. For example, caregivers who cook at home infrequently might be less likely to prepare breakfast for their children, which is associated with an increased risk of children becoming obese [41,42]. This is supported by our finding that children who have a low frequency of home-cooked meals are more likely to skip breakfast and to eat snacks freely (Table 1). We also found that the significant association between home cooking and obesity disappeared after adjusting for children's eating behaviors, including skipping breakfast and snacking habits (Table 3, Model 2). In previous systematic reviews examining the association between parental practices and children's consumption of unhealthy foods (including snacks and sugar-sweetened beverages), restrictive parental guidance/rulemaking and control of the availability of unhealthy foods were the practices that were most positively associated with children's consumption of unhealthy foods [43,44]. Children who snack frequently have been shown to consume higher total energy and energy from sugars [45]. Therefore, a low frequency of home cooking may be a proxy for less effective parental practice in terms of children eating healthy foods, which could explain the association with obesity in children.

A third potential explanation for this association is that home cooking may lead to a healthy diet because children eat foods similar to those consumed by their parents.  In contrast, when children eat outside the home or consume prepared meals, they select what they want and thus eat different foods from those eaten by their parents. Previous studies have reported that children who eat similar foods to those eaten by their parents are more likely to have healthy diets [38,46], suggesting that children may miss out on specific nutrients or food types, such as vegetables, if they are served a separate "child meal". Home cooking may also create a supportive and positive food environment for children. Creating a positive atmosphere at mealtime supports children's opportunities to try new foods and to develop their own food preferences [22].

Several limitations of this study should be mentioned. First, we assessed the frequency of cooking using a simple questionnaire based on previous studies, but the validity and reliability of the questionnaire were not examined here or in these existing studies. However, we confirmed the plausibility of the results by testing the association of the frequency of home cooking with the child's vegetable intake and breakfast skipping. Second, we defined home cooking as a basic and simple practice, such as frying an egg, and we did not assess the quality of the meals being prepared. Therefore, caregivers who cook low-quality meals (e.g., meals with little variety or unhealthy meals) may be included in the high frequency of home cooking category. This may have led to an underestimate of the association between home cooking and children's obesity. However, in large-scale surveys, it is difficult to evaluate the quality of meals because a great deal of time would be required for this assessment. Additionally, our study focused on parents engaging in the behavior of preparing meals for their children rather than on the quality of the meals they prepared. Third, we did not account for caregivers' food knowledge, which is particularly important for preventing obesity in children; this topic warrants further research. Fourth, because our sample of school children was from only one city, the generalizability of the results may be low. Furthermore, the caregivers in the present study were well educated, and most of the respondents were mothers. Low parental socioeconomic status was linked to children's obesity, and we also found that low maternal educational attainment was significantly associated with children's obesity (data not shown); this may have led to an underestimate of the association between home cooking and children's obesity. Finally, because this was a cross-sectional study, we were unable to assess causality. Longitudinal studies or randomized controlled trials are needed in the future to clarify the effectiveness of home cooking in preventing obesity in children. Despite these limitations, we were able to demonstrate a significant association between a low frequency of home cooking and children's obesity, controlling for potential confounding factors, and our findings may be useful for identifying potential targets for interventions aimed at improving children's body weight management.

#### **5. Conclusions**

Our study has provided novel findings regarding the association between home cooking and children's body weight status. Home cooking presents an opportunity for parents to offer a model of healthy eating to their children and to pass on food traditions from their own culture. When children participate in meal preparation, they tend to eat healthy diets [47]. Future studies are needed to clarify the causal relationship and mechanisms through which home cooking influences children. Although the present study focused on body weight, future studies should also examine other physical, psychological, and social outcomes that may be associated with home cooking for children.

**Author Contributions:** Conceptualization, Y.T. and T.F.; Data Curation, Y.T. and T.F.; Methodology, Y.T.; Formal Analysis, Y.T.; Investigation, Y.T., T.F., S.D., and A.I.; Writing—Original Draft Preparation, Y.T.; Writing—Review and Editing, T.F.; Supervision, T.F., S.D., and A.I.; Project Administration, Y.T.; Funding Acquisition, Y.T. and T.F.

**Funding:** This research was funded by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS KAKENHI Grant Numbers 16H03276 and 19K14029).

**Acknowledgments:** We are particularly grateful to the staff members and the central office of Adachi City Hall for conducting the survey. We would also like to thank everyone who participated in the surveys. We would especially like to thank M.Y.K., S.A., and Y.B. from Adachi City Hall, who contributed significantly to the completion of this study.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

### *Article* **Modern Transference of Domestic Cooking Skills**

#### **Fiona Lavelle 1, Tony Benson 1, Lynsey Hollywood 2, Dawn Surgenor 2, Amanda McCloat 3, Elaine Mooney 3, Martin Caraher <sup>4</sup> and Moira Dean 1,\***

Received: 13 March 2019; Accepted: 15 April 2019; Published: 18 April 2019

**Abstract:** As the primary source of learning cooking skills; it is vital to understand what mothers think about the transference of cooking skills to their children. The current analysis aimed to highlight mothers' perceptions of children's involvement and cooking practices within the home setting. Sixteen focus group discussions were conducted on the island of Ireland (Republic of Ireland and Northern Ireland [UK]) with 141 mothers aged 20–39 years old. All focus groups were transcribed verbatim and an inductive thematic analysis using NVivo software was undertaken. Seven themes emerged from the dataset; (1) "How we learned to cook"; (2) "Who's the boss"; (3) "Children in the way"; (4) "Keep kids out"; (5) "Involvement means eating"; (6) "Intentions versus reality"; and (7) "Kids' 'interest' in cooking". These themes illustrate a lack of cooking skill transference in relation to everyday meal preparation in modern times. The culture of children in the kitchen has vastly changed; and opportunities for children to learn basic skills are currently limited. Further research is required to confirm the findings that emerged from this analysis.

**Keywords:** cooking; learning; mothers; children; adolescents; obesity; qualitative; environmentalinfluences

#### **1. Introduction**

The possession and application of cooking skills can have numerous health benefits including a greater diet quality, weight control, and even longevity of life [1–4]. In light of this, there has been a resurgence in cooking skills education and a push for the re-skilling of the general population to reinvigorate meal preparation in the home environment [5–7]. Cooking skills interventions are also being increasingly implemented as childhood obesity prevention strategies or as essential components in multidisciplinary prevention approaches [8–10] as recommended by the World Health Organization [11]. These interventions are utilized as a means of enabling children and adolescents to prepare healthy meals as alternatives to the use of ready meals and the consumption of food outside the home [2,4,11,12]. The need for children and adolescents to learn these cooking skills has been highlighted as an important life skill [11]. Research suggests that adolescents who are involved in home meal preparation present with a higher diet quality than their non-food preparing counterparts [13]. In addition, learning cooking skills at younger ages has also been linked to skill maintenance through to adulthood, cooking confidence and a better diet quality [14].

Despite understanding the importance of cooking skills development at a young age, the optimal source for learning these skills has been debated. While a substantial emphasis has been placed on teachers through the education system [14–17], other sources are also important. The mother has been consistently identified as the primary source for learning cooking skills [14,18]. In addition, mothers have been identified as key influencers of children's weight status [19–21] and learning from the mother is associated with greater cooking confidence and less consumption of unhealthy foods, emphasizing the valuable role of the mother as a primary source of learning [14]. However, due to the increasing demand of current modern lifestyles and external pressures, some research suggests that mothers may no longer possess the necessary skills or time to prepare a healthy diet [22] and, therefore, may no longer be able to pass on cooking skills to their children. Anecdotally, it has been suggested that there is a lack of skill transference occurring from mothers to children, however, this phenomenon has not been explored qualitatively in order to understand why this may be happening. Thus, the role of the mother as a current source of learning must be examined.

Given their key role as influencers on children's weight status and the primary source for learning skills that enable the preparation of a healthy diet, it is vital to understand what mothers think about the importance of cooking skills development in their children and how this can be best modeled in the home setting to promote confidence and learning and the passing on of these skills to their children. A greater understanding of mothers' attitudes, behaviors and feelings could help to inform strategies to promote and encourage the learning of cooking skills. Therefore, this analysis aimed to highlight mothers' perceptions of children's involvement and cooking practices within the home setting.

#### **2. Materials and Methods**

#### *2.1. Focus Group Recruitment*

The participants were recruited to partake in a cooking from "scratch" experiment [23], with an immediate follow up focus group, in a room adjacent to the kitchens, to discuss their perceptions of the cooking experiment and experiences of cooking in general. They were recruited by Social Market Research (a market research company based in the United Kingdom and Republic of Ireland (ROI)). Overall, 160 mothers (20–39 years old), both employed and unemployed, who were responsible for the main meal preparation at least 3 times per week, and who had at least one child (under the age of 16 years) currently living in their household, with a range of children's ages, were recruited, with the final sample consisting of 141 (due to non-attendance). Participants could also not have any strict dietary requirements (such as lactose intolerant or vegetarian, for the purposes of partaking in the cooking experiment). Sixteen focus groups were conducted, with eight held in Sligo, ROI and eight held in Coleraine, Northern Ireland (NI). Each group had six to ten participants. Participants were recruited from a 30-mile radius of both sites and included both urban and rural participants. Results are treated as one island of Ireland sample. Sociodemographic and food-related characteristics were collected before the beginning of the cooking experiment and focus groups.

#### *2.2. Focus Group Procedures*

The focus groups were conducted in line with the principles outlined in Kreuger and Casey [24]. The discussions were facilitated by an experienced moderator (DS) and an assistant moderator (FL). The focus groups followed a guided open-ended questioning route relating to experiences of the cooking experiment and cooking habits and behaviors in general, an outline of the topic guide can be seen in Table 1. Probing questions relating to children's involvement in cooking were used for all mentions of children. The focus group topic guide was developed from a literature review [25] and earlier individual interviews conducted on the island of Ireland relating to cooking behaviors and habits [26]. Additionally, the guide was piloted with two focus groups, one group who had not conducted the cooking experiment (for general flow of the question route and the wording of the questions) and one group after piloting of the cooking experiment. The moderator emphasized the importance of all participants contributing to the discussion, and that all opinions and points were equally valid. The assistant moderator was present to take notes and facilitate the direction and flow of the discussion. All participants were assured of their confidentiality and all discussions were audio

recorded. Each focus group discussion lasted between 50 and 65 min. Upon completion of the focus group, each participant was thanked and given an honorarium (£50/€50) and a cookbook to compensate for their time (including the cooking experiment) and travel.

#### *2.3. Institutional Review Board*

The study was conducted in line with the guidelines laid down in the declaration of Helsinki. All participants provided written and verbal consent and were aware that they could withdraw from the research study at any point. The study was approved by the Research Ethics Committee within The School of Biological Sciences at Queen's University Belfast.

#### *2.4. Analysis of Focus Group Transcripts*

Focus group discussions were professionally, independently transcribed verbatim and checked for accuracy by the moderator and then imported into Nvivo 11 (QSR International Pty Ltd, Doncaster, Victoria, Australia) for analysis. An inductive thematic analysis in line with Braun and Clarke [27,28] was undertaken. The dataset used in this analysis involved all instances where participants discussed children in the kitchen environment including discussion of when they were children.

All transcripts were read and re-read by two of the authors in order to achieve data immersion. Subsequently, all data relating to "children" were coded for this analysis. The next phases involved grouping codes together to form potential themes, inspecting these themes for overlap and where necessary refining the themes. This refinement ensured that there were "clear and identifiable distinctions" between the themes and that there was no overlap [27].

An inter-rater process was used throughout the entirety of the analysis. Initially, two researchers (FL, a sport and health scientist, and TB, a health psychologist) independently coded 3 randomly selected transcripts (18% of the transcripts). The coders had an initial agreement of 90% on the coding of the transcripts. The codes were discussed to verify their applicability to the data, and agreement was reached on all codes upon discussion. Following this, FL coded the remaining transcripts and TB coded a further 5 transcripts, leading to 97% coding agreement across these 8 transcripts. Then, FL grouped codes to form potential themes. The themes were inspected for overlap and consensus was reached on all themes through discussion (TB and MD, a consumer food choice psychologist). Illustrative quotes were then extracted from the data to demonstrate typical views within each theme. Data saturation was reached within this topic area as no new codes appeared after the first ten transcripts. Sociodemographic data was summarized using SPSS v22 (IBM Corporation, Armonk, NY, USA, 2013).

#### **3. Results**

#### *3.1. Participant Characteristics*

The characteristics of the 141 participants can be seen in Table 2. Mean age was 30.45 years (SD 5.70).

**Table 2.** Demographic and Sociodemographic Characteristics of Focus Group Participants (*N* = 141).

**Table 2.** *Cont*.

\* Junior Cert (ROI)/GCSE (NI)—Age 15/16 years, exams taken midway through secondary school.

Mothers with a wide range of food related behaviors and levels of cooking and food skills confidence were recruited, as shown in Table 3.

**Table 3.** Food Related Characteristics of Participants (*N* = 141).

**Table 3.** *Cont*.

\* Participants were asked "Do you prepare/cook Breakfast/Lunch/Dinner during weekdays, weekends or both? (including preparing cold dishes like salads, or reheating ready-made foods)" † This participant was responsible for the meal preparation of their household, however, this consisted of collecting the takeaway. ‡ Cooking and food skills confidence were measured using a paper pen version of the validated measure in Lavelle et al. [29].

#### *3.2. Overview of Themes*

Through thematic analysis of the focus group transcripts, seven themes were constructed: (1) "How we learned to cook"; (2) "Who's the boss?"; (3) "Children in the way"; (4) "Keep kids out"; (5) "Involvement means eating"; (6) "Intentions versus reality"; and (7) "Kids' interest".

The culture of children being present in the kitchen appeared to revolve around the mother–child dynamic, with an underlying shift in this dynamic, from mothers being in control in previous generations to currently the child dictating meal choice. This shift appeared in two themes, "How we learned to cook" and "Who's the boss?", as described below.

(1) **How we learned to cook.** Here, participants discussed how they were present in the kitchen from a young age and how they learnt to cook from their mothers.

"*When I was younger mum always had us in the kitchen and teaching us how to cook and that.*" ROI FG2

The majority of participants claimed that they had to help with the dinner. There was no choice and it was what was expected of them and part of their family dynamics.

"*When we were younger my mum was out working an awful lot and I was minding the younger ones*

... *I just remember cooking at a really young age...*"

"*Oh yeah I'd have done that stand on the chair [because] you couldn't reach.*" ROI FG6

Some of the mothers noted that in some instances they had to assume the role as meal preparer in its entirety for their families. This is a sharp contrast to current practices where only two mothers of the 141 involved in the focus groups mentioned their older children helping with every day meal preparation. Thus, the culture of children helping in the kitchen and "doing jobs" in the kitchen is a rarity.

(2) **Who's the boss?** This theme highlights how the power of food choice has shifted to the child. This shift has put extra pressure and stress on the mother and has changed the 'cooking a meal' experience as well as what preparing a meal actually entails. Mothers claim that children dictate

what type of food is prepared by being fussy eaters or liking different textures or by how food is eaten (for example with their hands).

"*We all have di*ff*erent dinners in our house. So, because my wee (small*/*young) boy is like three so he's like 'I don't like that, I don't like that' and my wee girl she would rather sit with like salads, like she just loves all that so it's really di*ffi*cult in my house* ... *.My wee girl hates mince so like, you know your spag bol (spaghetti Bolognese) that you would love really quick or like cottage pie or anything like that she's 'no' so I know she's not going to eat it* ... *There's always one with something di*ff*erent in my house.*" NI FG5

In every focus group, it was mentioned that the participants cook to cater to their children's wants and needs, *"What the wee ones [the children] want to eat"* (NI, FG 8). Sometimes they are unaware of this level of control, and believe that they are making "compromises", although still preparing what the child wants.

 ROI FG6

If mothers do not want to eat what their children are eating, they make multiple dinners to avoid arguments, tantrums or revolt. To cope with the demand of having to make multiple dishes, some participants resorted to the use of convenience products instead of deciding what is to be eaten.

From these added stresses and pressures in the kitchen, two negative themes arose, "Children in the way" and "Keep kids out" with over three quarters of the focus groups having discussed children being in the way of their cooking and not wanting the children in the kitchen when they are cooking.

(3) **Children in the way.** This strongly presented theme revolves around the impact of having children present in the kitchen on the mother's current cooking practices. It highlights how children, "*little tigers*", are in the way when mothers are trying to prepare a meal, hanging on to the mothers or shouting and pulling at them.

"*I have 2 kids running about pulling me grabbing me mummy, mummy, mummy* ... *then babies looking fed and it's just madness.*" NI FG2

Some of the mothers mentioned that they would like a "*babysitter*" to occupy the children so that the participants were able to cook a meal. When children have disabilities requiring extra time or can have problems with food, this results in less time for the mother to cook. When faced with these situations, mothers tend to cope by cooking quickly, and by taking shortcuts, such as using convenience products, or by cooking food when the children are out of the way in school or in another room playing.

"*Like I have 5 kids fluttering around and you just don't have time to be standing with a flipping wooden spoon* ... " ROI FG1

(4) Keep kids out. This theme revolves around what stops mothers having their kids in the kitchen and involving them in the cooking process. The participants stated that they are too busy to deal with the mess children create in the kitchen as at times children can leave the kitchen looking like a *"bomb site".*

#### "*See because they'll just create such a mess.*" NI FG8

Along with the potential mess of letting the children in the kitchen, participants also noted concerns over the safety of having children in the kitchen.

"*Do you not be worried about them using a baker [oven] and things at that age?*"

"*Well I don't let my 4 year old use the cooker.*"

"*Oh no obviously.*"

"*The 13 year old she says yeah they have to use the cooker in school and stu*ff *so.*"

"*Oh I see now aye it just sounds really young still doesn't it though.*" NI FG4

While not as prevalent, there were also positive themes relating to the transference of skills from the mother to the child—"Involvement means eating" and "Intentions versus reality". The themes were mentioned multiple times within a smaller number of focus group discussions. While some transference of skills to the child occurring may happen as a result of these themes, the skill level being transferred may not occur frequently, not happen in all situations, and the type of skills transferred may not be optimal for everyday living.

(5) Involvement means eating. The "involvement means eating and trying foods" theme highlights the participants' perceptions about their children eating different types of food or food they have previously refused when they are involved in the preparation of the food.

"*My wee girl doesn't like vegetables or anything I think 2 or 3 weeks ago I got her to help me make lasagne, she loves pasta. I got her to help me make it and oh my god there was a clear plate so she loved it, she doesn't like peas or carrots or courgettes (zucchinis) or onions or anything like that everything in and then she ate it all, no questions asked.*" NI FG5

Some of the participants felt that children experiencing the food ingredients in the kitchen rather than it being presented to them as a complete dish to eat removes the fear of the unknown.

"*Whereas if she was actually helping to make (dinner)* ... *She'll eat anything if she kind of knows what it is but whenever they don't seem to know what it is they are just a bit wary of it.*" NI FG3

(6) **Intentions versus reality.** This theme addresses the concept of cooking with children. Mothers in general expressed a desire for their children to be able to cook to help them in their future.

"*Yeah and you want them to be able to know how to cook, so that when they hit 18 they wouldn't just live on little packets of you know pasta or takeaway, that they have some idea, they can come in they can make a Spaghetti Bolognese or they can do the basics.*" ROI FG1

However, when mothers discuss instances of when they cook with their children they mention baking, which is seen as a fun activity or random dishes that children pick to cook rather than everyday dishes that form their diet.

"*My little one loves to bake and stir and she'll make pizza for her friends, you know, she loves doing stu*ff *like that and all sorts of nonsense.*" NI FG8

Participants also referred to the occasional instances where they had the children make the meal with them, to try and encourage them to eat the food, as discussed in the previous theme. In addition, the participants mentioned eating food they do not like that children have prepared to encourage the children to cook.

In the final theme, participants discussed their child's interest or stated that they were not interested in cooking. It was unclear whether children showed an interest in cooking due to greater cooking exposure or whether children were naturally interested. This theme is detailed below.

(7) **Kids' "interest" in cooking.** This theme was present in eight of the 16 focus groups, however, not all instances were positive, as some reported that their children had no interest in cooking.

"*(Cooking) bores my 10 year old, (they're) not interested.*" NI FG4

Some mothers commented on their children's interest in cooking and that they wanted to cook and learn to cook at home or in home economics.

"*Well he's doing home economics and all in school and he loves to cook yeah.*" ROI FG5

Some participants proposed that the child's interest in cooking arises as a way of gaining a sense of independence instead of just having their '*dinner set down in front of them*' and that they gained a sense of pride and achievement.

#### **4. Discussion**

This analysis investigated the phenomenon of transgenerational cooking skills transference in modern times. The findings indicate that the culture of children being in the kitchen has vastly changed, and opportunities for children to learn basic and fundamental food related skills are not present in the current climate. Recently, home economics teachers in Australia highlighted how children "don't have a clue" about food skills when they enter schools due to parents' time constraints and perhaps due to parents' limited skills [30]. They stressed the importance of adolescents learning cooking and food skills to enable them to make informed food choices [30].

In line with recent research showing that the mother is the primary source of learning [14,18], the transference of cooking skills from the mothers' mothers was found. This relates to past behaviors and learning and is therefore logical that these participants report the same source that has been discussed previously in the literature. Mothers reported how they were involved in the cooking process in the kitchen and were sometimes responsible for cooking when they were children. This is in contrast to current practices, with a minority of mothers mentioning their children helping with the everyday meal preparation. The mothers' felt a lack of control when the children were in the kitchen and the children distract the mothers from cooking. This caused extra stress and negativity to the whole cooking experience. In addition, mothers did not want their children in the kitchen because of safety concerns, not considering that they themselves had previously been in the kitchen at a similar young age. Additionally, although there was a mention of children using different appliances at certain ages in school, some participants still showed a hesitancy about this and there appeared to be uncertainty over the appropriate age for including children in cooking. Furthermore, the participants did not want to have to clean up the mess created by having children in the kitchen. This idea of having to clean up after the children may be a misunderstanding because, as part of learning basic food skills, children need to learn about cleaning up after cooking and about learning to cook in a neat and safe manner [31]. However, this may also reflect a societal change, where more women are in employment and may have limited time to undertake household responsibilities [32] and, therefore, removing children from the kitchen may be seen as a means to reduce their workload. However, the removal of the children from the kitchen may result in a lack of skill transference.

Furthermore, children are currently dominating meal choice, which in turn influences the type of cooking that occurs and increases the pressure on mothers through the cooking of multiple meals. This is in direct contrast to Lai-Yeung [33] who found that Hong Kong mothers dictate food choice decisions. However, this theme is in line with other western studies [26,34,35] where there has been an emergence of the "junior consumer" deciding on the food to be purchased and prepared, suggesting the existence of cross-cultural differences in this area.

The "rareness" of skill transference occurring from parent to child was alluded to by Lai-Yeung [33] and minimal transference may have been occurring from a minority of participants to their children. Cooking experiences mentioned tended to be fun activities, not daily occurrences and not daily meal preparation. Although any level or element of cooking is positive, the infrequency and type of cooking contribute to the lack of transference of skills.

These changes in cooking practices may have detrimental effects on the learning of cooking skills, where children do not perform the everyday tasks in meal preparation (including food skills such as cleaning up safely after creating a mess in the kitchen), or are being removed from the kitchen and in

turn are missing crucial opportunities to learn basic, fundamental skills. This may be contributing to the disappearance of important life skills.

Involving children in cooking has been used previously as a successful strategy to overcome picky eating [36], increase consumption of healthier foods [37] and to increase willingness to taste unfamiliar foods [38]. This strategy has the potential to combat the lack of transference of skills. In addition, it may help to reduce the impact of the child dictating the meal choice, as the child would be more open to and aware of different foods, potentially increasing their food neophilia (i.e., their openness/willingness to trying new and novel foods). Greater willingness to try new foods could be promoted as a key benefit in learning cooking skills.

Not everyone is interested in cooking; however, as it is a valued life skill, it would be appropriate to encourage it across all genders. Parents have been previously found to be supportive of this skill transference [33]. Mothers in this research felt that cooking could be a way for their children to assert their independence and achieve a sense of pride. The ability for cooking skills to be empowering in adult settings has been proposed in previous research [22] and from our results it is suggested that the sense of achievement and empowering element of having cooking skills is not only found in adults but across all ages. Teaching children skills in other domains such as in research has been shown to empower children to become engaged researchers and that the greater is the participation, the more experienced and competent the child becomes, and the greater is the sense of empowerment as the child becomes more effective in the execution of skills [39]. How cooking skills can provide a sense of independence and pride could be a key focus for the promotion of cooking skills in combination with health benefits.

#### *4.1. Limitations*

A limitation to this research is that the sample consisted only of mothers. However, mothers have been reported as the primary source of learning cooking skills [14] and an investigation into the current situation was therefore warranted. As some of the participants were in employment, further research is needed into the role of the primary daytime carer of the child, for example grandparents, in the transference of cooking skills. Additionally, there may be some cross-cultural differences in the findings. While there may be limited generalizability (as is inherent in qualitative research), the large number of focus groups with a broad range of mothers with varying food-related behaviors and practices allowed for an extensive range of descriptive ideas that may contribute towards reducing these differences. Further quantitative research in this area could help with the generalizability of the results.

#### *4.2. Implications for Research and Practice*

From the above findings, the authors propose two key recommendations: (1) upskilling of mothers' food skills in relation to organizing meals and preparation time, to allow for children to be involved and to reduce stress; and 2) creating an awareness of the importance of kids being in the kitchen and helping with everyday meal preparation. These recommendations may have implications for future interventions and future research. Recommendations 1 and 2 could be implemented through increased numbers of family inclusive interventions, to help parents to acclimatize to children cooking alongside them. This may show parents that children can be involved and assist with everyday meal preparation and highlight different age appropriate cooking skills and tasks. Our findings support the idea of having interventions that focus on the mother–child dyad. Inclusive family interventions may promote the use of these cooking skills to prepare healthy and nutritious meals.

The inclusion of practical cooking skills in any nutrition component of an obesity prevention program is key, to provide individuals with the necessary skills to prepare healthy food [22]. Future longitudinal research could investigate the use of cooking skills over the life course and its impact on weight status. Additionally, the influence of parenting styles on the learning of cooking skills is a key novel area that requires further investigation, as some of the findings in this analysis

show children dictating food choices instead of parents which could suggest a shift from the more authoritarian/authoritative parenting approaches in the past to a more permissive/uninvolved style [40]. This could be problematic as a recent review of parenting styles and future weight status [41] suggests that an authoritative parenting style may have a protective role against future overweight and obesity [41]. Although mothers currently have the responsibility of passing on cooking skills, with shifting family dynamics and the increase in the "stay at home husband", future research could investigate if fathers are currently involved in meal preparation and whether this impacts on children's involvement in meal preparation.

Previous research has stressed the importance of cooking skills education through the educational system [14–17], however, initially the role played by the educational system was to expand upon the skills learned in the home environment [17]. Presently, the lack of skills that children present with at school has been highlighted [31] and a push for compulsory practical education can be seen in numerous countries [14,15,31]. It is suggested that a combination of the above methods is essential to promote the use of cooking skills and to empower individuals to prepare healthy nutritious meals to improve their diet quality as a strategy for obesity and other diet-related disease prevention and management.

#### **5. Conclusions**

The findings suggest that the culture of children cooking in the kitchen has vastly changed, and opportunities for children to learn basic and fundamental skills are currently lacking which may have detrimental effects on their diet quality. The qualitative nature of the study provides insights into why mothers may not involve their children in cooking including children creating a mess and distracting the mothers from their own cooking and may help with the design of future interventions targeting these behaviors. In addition, a greater awareness of age-related skills and tasks for children in the kitchen should be promoted.

**Author Contributions:** Conceptualization, F.L. and M.D.; data curation, F.L.; methodology, F.L., L.H., D.S., A.M., E.M., M.D. and M.C.; project administration, M.D.; formal analysis, F.L., T.B. and M.D.; investigation, F.L. and D.S.; resources, M.D., A.M., E.M. and L.H.; supervision, M.D.; writing—original draft, F.L.; writing—review and editing, F.L., T.B., M.D., A.M., E.M., L.H., D.S. and M.C.; and funding acquisition, M.D., A.M., E.M., L.H., and M.C.

**Funding:** This material was based upon work supported by safefood, The Food Safety Promotion Board, under Grant No. 11/2013 for the period May 2014–October 2015.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

#### **References**

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).


2.3.2. Qualitative

The obtained sediment for quantitative analysis was centrifuged again and the supernatant was discarded. After vortexing, two drops (100 μL) of sediment were placed separately on a slide and distributed over an area of about 24 × 24 mm. Examination of pollen slides was performed using an optical microscope (400× or 1000×, as appropriate). The percentage of representation for each type of pollen was calculated by counting at least 500 pollen grains per sample. The pollen grains were classified as pollen type, as genus or a single species, when it was possible. Following the recommendations suggested by [13], the pollen frequency classes were determined.

### *2.4. Physico-Chemical Analysis and Color Determination*

Quality parameters including honey freshness (HMF and diastase content), moisture, electrical conductivity, pH and free acidity were determined in duplicate and following methodologies proposed by the International Honey Commission [14].


**Complexes of Polysaccharides and Glycyrrhizic Acid with Drug Molecules − Mechanochemical Synthesis and Pharmacological Activity**

A. V. Dushkin, T. G. Tolstikova, M. V. Khvostov and G. A. Tolstikov

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/48095


**8. Conclusions**

As an easy-to-integrate planar circuit, the SIW technology lays the foundation for the design and implementation of high-performance, planar, low-cost, and easy-tointegrate microwave passive circuits. This chapter describes the novel circuits based on substrate-integrated waveguide, including filter, power divider, switch, phase shifter, duplexer, crossover, and so on.


**5. Vasculitis**

may develop during the anti-TNF-alpha treatment. The anti-TNF-alpha treatment increases the IL-17 and IFN-ϒ expression and disturbs the balance between Th17 and Treg in favour of

Systemic lupus erythematosus (SLE) is a common autoimmune disease, with 10% of SLE cases being drug-induced. The autoimmune drug-induced response is idiosyncratic, influenced by multiple factors, such as genetics, comorbidities, interactions with other medicinal products and external environmental factors [23]. Drug-induced lupus erythematosus (DILE) is defined as a lupus-like disease that is temporally related to drug exposure (from 1 month after the commencement of drug application but sometimes even more than 10 years) [24].

DILE may not meet all the SLE criteria. The most common manifestations are arthritis, serositis, the presence of ANA antibodies and anti-histone antibodies. The most important criterion

DILE induced by TNF-alpha inhibitors appears to be a separate DILE group with different signs compared to classical DILE. Women are more often affected than men, with an average age between 46.2 and 50.9 years. The average time to the manifestation of symptoms is 40.6 weeks from the commencement of drug treatment. Skin manifestations occur more frequently than in classical DILE and include butterfly erythema, photosensitivity and other skin manifestations of systemic and sub-acute lupus. The exact mechanism of DILE formation during anti-TNF-alpha treatment is unknown. Post-marketing follow-ups have demonstrated that DILE induced by TNF-alpha inhibitors may occur across all anti-TNF-alpha inhibitors. However, it is more often reported with the use of infliximab (0.19–0.22%) and etanercept (0.18%) compared to adalimumab (0.10%). An increase in ANA or anti-DNA antibodies in patients treated with anti-TNF-alpha therapy is known and relatively common [26]. The frequency of elevated ANA antibodies was higher in a greater number of patients treated with infliximab compared to a group of patients treated with etanercept [27]. Anti-dsDNA antibodies as well as ENAs (extractable nuclear antibodies) and low complement levels have been described more often than in case of classical DILE. Particularly, anti-histone antibodies have

is that the symptoms cease after discontinuing application of the suspected drug [25].

been more common in DILE induced by anti-TNF-alpha treatment [28, 29] (**Figure 2**).

The basic therapeutic procedure is the discontinuation of the treatment with the drug that induced the symptoms. In more severe conditions, it is necessary to add suppressors—corticosteroids, azathioprine, cyclosporine and methotrexate. Treatment selection is also based on the status of the underlying disease and comorbidities of the patient. In psoriasis, it is recommended to avoid systemic corticosteroids for a possible rebound phenomenon after discontinuation. There is no need to discontinue the treatment of anti-TNF-alpha in the case of ANA positivity or in very mild DILE manifestations [26]. Only limited data are available in the literature describing a switch of the treatment to another anti-TNF-alpha agent. Some authors claim that a similar reaction can be caused by any of the agents from the group of anti-TNF-alpha inhibitors [30]. As stated by Lomicova et al., an alternative treatment for chronic

Th17. These two factors may result in the development of sarcoidosis [22].

**4. Lupus-like syndrome**

264 Antibody Engineering

The manifestations of vasculitis are another disease that is associated with the anti-TNF-alpha treatment. Several case reports and patient groups have been described in the literature. In almost half of the cases, leukocytoclastic vasculitis was histologically described, while the other patients included cases of necrotising vasculitis, lymphocytic vasculitis and urticarial vasculitis [32].

An aggregate paper of 118 cases of vasculitis newly formed during the anti-TNF-alpha treatment (99 cases of rheumatoid arthritis, 8 Crohn's disease, 5 juvenile rheumatoid arthritis, 3 ankylosing spondylitis, 3 psoriasis) presented skin manifestations in 86% of patients. The anti-TNF agent administered was etanercept in 60 (51%) cases, infliximab in 51 (43%), adalimumab in 5 (4%) and other agents in 2 (2%). Purpura was manifested in 63% of the patients, whereas others had other skin manifestations of vasculitis, such as ulcerations, nodosities, maculopapular manifestations, etc. Systemic involvement was observed in 24% of patients. Immunological examinations showed that the antinuclear antibodies (ANAs) were positive in 27 patients and antineutrophil cytoplasmic antibodies (ANCAs) in 11 patients (pANCA in 5 patients and cANCA in 1 patient). Treatment in the form of anti-TNF-alpha discontinuation was used in 11 patients, 71 of whom completely recovered (41% of them had additional immunosuppressive therapy) [33]. Mohan et al. describe in an aggregate paper including 50 patients that almost 63% of patients experienced a complete recovery of the manifestations after discontinuation of the anti-TNF-alpha treatment [34].

Vasculitis manifestations in patients with severe seropositive rheumatoid arthritis are debatable, because the manifestations may be evaluated as rheumatic vasculitis, which is an extraarticular manifestation of rheumatoid arthritis and not drug-induced vasculitis. In such cases, some authors recommend discontinuation of the anti-TNF-alpha treatment with possible reexposure to the given treatment [32]. The same situation applies also to patients with IBD, where leukocytoclastic vasculitis can be associated with the disease itself [35].

The pathogenesis of vasculitis associated with anti-TNF treatment is not completely explained. An immune complex-mediated hypersensitivity vasculitis may be related to the development of antibodies against anti-TNF agents, but in this hypothesis, the cases with etanercept should be less frequent since the treatment with the soluble receptor induces less antibody formation than monoclonal antibodies. Overexpression of type I interferon secondary to imbalance between Th1 and Th2 cytokine production under TNF inhibition may favour induction of autoimmune disorders such as vasculitis [15].

anti-TNF-alpha therapy for the alopecia areata was not confirmed. In the literature, however, there are cases of newly developed manifestations of alopecia areata, total and universal alope-

**Figure 3.** Adalimumab induced alopecia areata, spontaneous complete disappearance of the symptoms after 10 months

Immune-Mediated Skin Reactions Induced by Recombinant Antibodies and Other TNF-Alpha…

http://dx.doi.org/10.5772/intechopen.72449

267

French authors present data from a multicentre prospective study of patients who received anti-TNF-alpha treatment due to dermatological (11 patients), rheumatological (11 patients) and gastroenterological indications (7 patients). From these patients, 10 were treated with infliximab, 11 with adalimumab and the following 8 with etanercept. In the population, a total of 29 patients were diagnosed with alopecia areata, which was confirmed by a dermatologist. The manifestations of alopecia areata were in the area of scalp and chin in 79% of the patients. There were interesting findings related to concomitantly associated immune-mediated diseases, namely the occurrence of vitiligo, psoriasis or psoriasis-like manifestations and autoimmune thyroiditis. In the study group, nine patients had a positive family history of alopecia areata or vitiligo. A total of 14 patients discontinued the anti-TNF-alpha treatment and 15 patients continued the treatment. From patients who discontinued treatment, four were treated with infliximab, six with adalimumab and four with etanercept. Improvement up to complete disappearance of the symptoms was observed in 76% of the patients, while there was no difference

between the groups in which the treatment discontinued or continued [44] (**Figure 3**).

**8. Lichen ruber planus and lichen planus-like reaction**

Etiopathogenesis of alopecia areata is not clear. Some authors explain the occurrence of alopecia areata similar to TNF-alpha-induced psoriasis. Inhibition of TNF-alpha results in dysregulation of cytokines and subsequent production of IFN-alpha, which results in a pathological process [43]. However, further research is needed to better understand the occurrence of alo-

Several cases of lichen planus and lichen planus-like paradoxically incurred lesions induced by anti-TNF-alpha therapy were reported in the literature. The manifestations have different clinical variability, including mucosal signs, but histologically they have signs of lichen planus. The clear cause of lichenoid reactions in the treatment of anti-TNF-alpha is not known. Lichen is T-cells and dendritic cells mediated dermatosis. As with other immune-mediated diseases,

cia during anti-TNF-alpha treatment [42, 43].

without the drug discontinuation.

pecia areata during anti-TNF-alpha therapy.

#### **6. Pyoderma gangrenosum**

Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis. PG is manifested by severe painful non-infectious pustules, nodules and necrotising ulcerations. The defects are sharply demarcated, round, with distinctly dark red undermined edges. The manifestations occur mostly on the shins, but they can also be found on the torso and other body parts. The manifestations of PG can be divided into several clinical forms, namely pustulous, bullous, a vegetative form of the disease and a separate peristomic form [36]. The peristomic form is a sign of pyoderma gangrenosum with pathergy; any trauma and injury of skin cover can cause new manifestations of the disease. The peristomic form may develop from 2 weeks to 3 years after the initial creation of the stoma [37]. Key factors in the etiopathogenesis of the disease are IL1B, IL-17, TNF-alpha and other chemokines that activate neutrophils for their activity. Genetic examinations point to several autoinflammatory genes, including pyrin innate immunity regulator (MEFV) and prolineserine-threonine phosphatase interacting protein-1 (PSTPIP1) [38]. About 50% of PG cases are associated with underlying diseases, such as inflammatory bowel disease, rheumatoid arthritis, myelodysplastic syndrome and haematological malignancies [39, 40]. Several papers indicate that refractory forms of PG are well responsive to the treatment with TNF-alpha inhibitors. One of the latest summary papers on drug-induced manifestations of pyoderma gangrenosum describes five case reports of pyoderma gangrenosum induced by an anti-TNF-alpha therapy. Three patients had manifestations induced by infliximab, one case of PG was induced by etanercept and one by adalimumab. Etiopathogenesis of PG induced by TNF-alpha inhibitors may represent paradoxical reaction due to a shift towards Th-17 polarisation [41].

### **7. Alopecia areata**

Pathogenesis of alopecia areata is associated with TNF-alpha, which, as demonstrated in *in vitro* studies, inhibits hair follicle growth. However, in clinical trials with etanercept, the efficacy of Immune-Mediated Skin Reactions Induced by Recombinant Antibodies and Other TNF-Alpha… http://dx.doi.org/10.5772/intechopen.72449 267

Vasculitis manifestations in patients with severe seropositive rheumatoid arthritis are debatable, because the manifestations may be evaluated as rheumatic vasculitis, which is an extraarticular manifestation of rheumatoid arthritis and not drug-induced vasculitis. In such cases, some authors recommend discontinuation of the anti-TNF-alpha treatment with possible reexposure to the given treatment [32]. The same situation applies also to patients with IBD,

The pathogenesis of vasculitis associated with anti-TNF treatment is not completely explained. An immune complex-mediated hypersensitivity vasculitis may be related to the development of antibodies against anti-TNF agents, but in this hypothesis, the cases with etanercept should be less frequent since the treatment with the soluble receptor induces less antibody formation than monoclonal antibodies. Overexpression of type I interferon secondary to imbalance between Th1 and Th2 cytokine production under TNF inhibition may favour induction of

Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis. PG is manifested by severe painful non-infectious pustules, nodules and necrotising ulcerations. The defects are sharply demarcated, round, with distinctly dark red undermined edges. The manifestations occur mostly on the shins, but they can also be found on the torso and other body parts. The manifestations of PG can be divided into several clinical forms, namely pustulous, bullous, a vegetative form of the disease and a separate peristomic form [36]. The peristomic form is a sign of pyoderma gangrenosum with pathergy; any trauma and injury of skin cover can cause new manifestations of the disease. The peristomic form may develop from 2 weeks to 3 years after the initial creation of the stoma [37]. Key factors in the etiopathogenesis of the disease are IL1B, IL-17, TNF-alpha and other chemokines that activate neutrophils for their activity. Genetic examinations point to several autoinflammatory genes, including pyrin innate immunity regulator (MEFV) and prolineserine-threonine phosphatase interacting protein-1 (PSTPIP1) [38]. About 50% of PG cases are associated with underlying diseases, such as inflammatory bowel disease, rheumatoid arthritis, myelodysplastic syndrome and haematological malignancies [39, 40]. Several papers indicate that refractory forms of PG are well responsive to the treatment with TNF-alpha inhibitors. One of the latest summary papers on drug-induced manifestations of pyoderma gangrenosum describes five case reports of pyoderma gangrenosum induced by an anti-TNF-alpha therapy. Three patients had manifestations induced by infliximab, one case of PG was induced by etanercept and one by adalimumab. Etiopathogenesis of PG induced by TNF-alpha inhibitors may

represent paradoxical reaction due to a shift towards Th-17 polarisation [41].

Pathogenesis of alopecia areata is associated with TNF-alpha, which, as demonstrated in *in vitro* studies, inhibits hair follicle growth. However, in clinical trials with etanercept, the efficacy of

where leukocytoclastic vasculitis can be associated with the disease itself [35].

autoimmune disorders such as vasculitis [15].

**6. Pyoderma gangrenosum**

266 Antibody Engineering

**7. Alopecia areata**

**Figure 3.** Adalimumab induced alopecia areata, spontaneous complete disappearance of the symptoms after 10 months without the drug discontinuation.

anti-TNF-alpha therapy for the alopecia areata was not confirmed. In the literature, however, there are cases of newly developed manifestations of alopecia areata, total and universal alopecia during anti-TNF-alpha treatment [42, 43].

French authors present data from a multicentre prospective study of patients who received anti-TNF-alpha treatment due to dermatological (11 patients), rheumatological (11 patients) and gastroenterological indications (7 patients). From these patients, 10 were treated with infliximab, 11 with adalimumab and the following 8 with etanercept. In the population, a total of 29 patients were diagnosed with alopecia areata, which was confirmed by a dermatologist. The manifestations of alopecia areata were in the area of scalp and chin in 79% of the patients. There were interesting findings related to concomitantly associated immune-mediated diseases, namely the occurrence of vitiligo, psoriasis or psoriasis-like manifestations and autoimmune thyroiditis. In the study group, nine patients had a positive family history of alopecia areata or vitiligo. A total of 14 patients discontinued the anti-TNF-alpha treatment and 15 patients continued the treatment. From patients who discontinued treatment, four were treated with infliximab, six with adalimumab and four with etanercept. Improvement up to complete disappearance of the symptoms was observed in 76% of the patients, while there was no difference between the groups in which the treatment discontinued or continued [44] (**Figure 3**).

Etiopathogenesis of alopecia areata is not clear. Some authors explain the occurrence of alopecia areata similar to TNF-alpha-induced psoriasis. Inhibition of TNF-alpha results in dysregulation of cytokines and subsequent production of IFN-alpha, which results in a pathological process [43]. However, further research is needed to better understand the occurrence of alopecia areata during anti-TNF-alpha therapy.


**5. Proofs of the boundedness and convergence properties of smooth sliding mode controllers**

In this section, the proofs of the boundedness and convergence properties of the smooth sliding mode controllers are introduced. In particular, the convergence analysis of smooth sliding mode controllers will be explained and discussed to the finest detail. Lyapunov's direct method is used to handle the finite-time convergence of the tracking error vector to the boundary layer. Also, once in the boundary layer, the tracking error vector is said to have exponentially converged to a bounded region, as proven analytically.


**8. References**

234 Tribology in Engineering

publications from tribochemical ones.

mechanochemistry and tribochemistry have a formal character.

broadly encompass triboemission and triboplasma processes.

considered as a subset of mechanochemistry.

tribochemistry discipline.

**7. Conclusions**

goal of this Chapter.

**Author details**

*Automotive Industry Institute PIMOT, Warsaw*

Czesław Kajdas

*6.4.5. Common denominators of mechanochemistry and tribochemistry*

mechanochemically initiated polymerization, depolymerization and mechanolysis. It also considers lubricant design and lubricity process and, differentiates mechanochemical

At this point, it is proposed to assign *inorganic mechanochemistry* to *mechanochemistry* and, *organic mechanochemistry* to *tribochemistry.* Thus, major differences between

Considering that the excess energy (energy stored in a sytem) serves as the origin of enhanced reactivity of materials under mechanical treating, their common denominators

In the present Chapter understanding, there is only a formal overlap of these disciplines in terms of inorganic and organic chemistry. Accordingly, *mechanochemistry* is the *inorganic mechanochemistry* and, *tribochemistry* is the *organic mechanochemistry*. Tribochemistry is

The major denominatot for inorganic mechanochemistry, organic mechanochemistry, catalysis and tribocatalysis is the NIRAM-HSAB approach, because it allows accounting for most of very specific tribological findings. It also demonstrates how organic chemistry is changing via physical chemistry, chemical physics and nowadays by contributing to tribochemistry. Book chapter [82] details physical and chemical phenomena concerning the

Mechanically initiated chemical reactions in solids are not new and presently there are many practical and theoretical achievements. Since mechanically initiated chemical reactions in solids have not received adequate attention yet, first of all a better understanding between researchers dealing with mechanochemistry and tribochemistry is needed. It was a major

The new approach to mechanically initiated chemical reactions shows that the NIRAM-HSAB theory is important in accounting for most of very specific tribological findings and,

(2)

also allows to account for the first mechanochemical reactions, for example

or modify the mechanism of heterogeneous C - C bond splitting in polymers.

*Warsaw University of Technology, Institute of Chemistry, Płock, Poland*

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**2.7 Reduce environmental damage with magnet recycling programs**

Magnet recycling programs are an effective way to reduce the environmental damage caused by the disposal of magnets. By implementing magnet recycling programs, these materials can be recovered and reused, reducing the need for new materials to be mined or manufactured. There are several ways that magnet-recycling programs can be implemented.

#### *2.7.1 Magnets can be recycled into new magnets*

The recycling of magnets is an excellent way to reduce environmental damage. By recycling magnets, we are able to reuse them in a variety of ways. This not only reduces the amount of waste that ends up in landfills, but it also helps to conserve resources. When magnets are recycled, where old or discarded magnets are broken down into their base materials and then reformed into new magnet products [63] first, they are crushed into smaller pieces. These smaller pieces are then sorted by their magnetic properties. The magnet that is most magnetic is known as the ferrite, while the least magnetic is known as the neodymium. Once the magnets are sorted, they are then cleaned and smelted down. This process helps to reduce waste while conserving resources and energy. A sustainable solution benefits both the environment and the economy [64].

#### *2.7.2 Recycling magnets helps reduce environmental pollution*

Magnet recycling is one of the most efficient ways to reduce environmental pollution. Magnets, like most materials, are made up of natural resources. By recycling magnets, we can help reduce pollution and conserve these resources. The process of magnet recycling involves several steps:

The process of recycling magnets is not only efficient in reducing environmental pollution, but it is also cost-effective. By recycling magnets, we can save money on raw materials and on energy costs. In addition, recycling magnets help to create jobs in the recycling industry [65, 66].


**1. Introduction**

14 Epidemiology Insights

Sobel, J.D. (2007). Vulvovaginal candidosis. *Lancet*, Vol.369, No.9577, pp. 1961-1971. ISSN

Tumbarello, M.; Posteraro, B.; Trecarichi, E.M.; Fiori, B.; Rossi, M.; Porta, R.; de Gaetano

Verstrepen, K.J. & Klis, F.M. (2006). Flocculation, adhesion and biofilm formation in yeasts.

Vol.45, No.6, pp. 1843-1850, ISSN 0095-1137

Molecular Microbiology, Vol.60, No.1, pp. 5-15

Donati, K.; La Sorda, M.; Spanu, T.; Fadda, G.; Cauda, R. & Sanguinetti, M. (2007). Biofilm production by Candida species and inadequate antifungal therapy as predictors of mortality for patients with candidemia.  Several risk factor identified among patients hospitalized for long periods such as the exposition to broad spectrum antimicrobial and/or immunosuppressive chemotherapy, parenteral nutrition, and invasive medical procedures have contributed to this fact (Blumberg et al., 2001, Fraser et al., 1992). Despite some improvements in fungal BSI diagnosis during last years, candidemia diagnosis remains difficult. Besides, following the data appeared in the classical study from Berenguer and colleagues, only 50% of patients with disseminated candidiasis will have positive blood cultures and even fewer will have an antemortem diagnosis (15% to 40%) (Berenguer et al., 1993). Therefore, invasive candidemia is not easy to diagnose, has an expensive treatment and finally is a serious, often lifethreatening infection (Girmenia et al., 1996, Messer et al., 2009).

Although the incidence of candidemia has increased steadily among hospitalized patients during the eighties and nineties, recent series suggest that This increase has stabilized, but with great variations between different geographical locations with similar socio-economical development even in the same continent. For instance, in The Netherlands an increasing incidence of candidemia has been reported during the period between eighties and nineties (Voss et al., 1996) but on the other hand, in a neighbouring country such as Switzerland the incidence of *Candida* BSI infections remained unchanged during the same period (Marchetti et al., 2004). Therefore, it seems that there are some differences in the epidemiology of candidemia between different countries.

Besides, in recent years, a trend towards increasing resistance to both traditional and more recently introduced antifungal agents has been observed amongst invasive *Candida* infections, underscoring the need for continuous surveillance to monitor trends in incidence, species distribution, and antifungal drug susceptibility profiles.

Epidemiology of Bloodstream *Candida* spp. Infections

published by Nguyen *et al.* (Nguyen et al., 1998).

Stata 8.0 (Stata Corporation, Lenexa, TX).

**3. Distribution of Candida blodostream infections**

**In vitro susceptibility testing**

**Statistical analysis**

admissions.

Observed During a Surveillance Study Conducted in Spain 17

*Incident case of candidemia:* The incident isolation of *Candida spp*. from a blood culture. *New incident case of candidemia:* An episode of candidemia occurring more than 30 days after the initial incident isolation. *Breakthrough candidemia:* The incident isolation of *Candida* spp. from a blood culture

*Fever*: Peripheral body temperature equal or higher than 37.8°C *Neutropenia*: An absolute neutrophil count of less than 500 cells / mm3.

Antifungal susceptibility tests were performed by using the broth microdilution assay according to the methodology recommended by the CLSI (formerly known as NCCLS), document M27-A2 (NCCLS, 2002) using a microtiter plate. Each isolate was tested against different antifungal drugs at the indicated concentration range suggested in the CLSI document. Quality control (QC) was ensured by testing the CLSI recommended QC strains, *C. krusei* ATCC 6258, and *C. parapsilosis* ATCC 22019.The MIC endpoint for amphotericin B, azoles and echinocandins and interpretative MIC breakpoints for azoles and echinocandins were those suggested by the CLSI document M27-A2, but for the definition of the amphotericin B MIC breakpoints we used the values suggested from a previous study

The numbers of admissions and patient-days were collected to calculate incidence rates. The incidence rate for each hospital was calculated as the number of candidemias per 1,000 admissions, whereas the overall incidence was determined using summed denominators of patient-days and admissions to calculate pooled mean rates. The data generated during the year of the surveillance on the different risk factors, underlying diseases, morbidity and mortality were recorded in a Microsoft Access 2003 (Microsoft Corporation, Redmond, WA) based case report database. Categorical data were analyzed using Chi-square or Fisher's exact tests as appropriate, and continuous variables were compared using the t-test or Wilcoxon test according to the significance of the normality test. Spearman rank-order correlation was used to measure the relationship between the MICs of fluconazole and voriconazole. We performed univariate and multivariate analysis of factors associated with candidemia caused by isolates with decreased susceptibility to fluconazole. Variables significant at *p-*values of less than 0.05 by univariate analysis were included in a multivariate model using a repeated measures logistic regression model (backward and forward). Data were analyzed using the SPSS 11.0.1 software (SPSS, Inc. Chicago, IL) and

During the 12-month study period a total of 984 Candida BSIs were reported. The calculated overall incidence was 1.09 cases per 1,000 admissions, however the incidence rate changed a lot between the 40 centers enrolled in this study and ranged from 0.76 to 1.49 cases per 1,000

any reason.

*Adult patients:* All patients whose age was over 14 years old. Table 1. Definitions according to NHSN (formerly NISS) used in this study

from a patient receiving systemic antifungal therapy for

The epidemiology of candidemia has been extensively studied in many countries and there are some large series published in this field (Alonso-Valle et al., 2003, Atunes et al., 2004, Banerjee et al., 1991, Colombo et al., 2006, Diekema et al., 2002, Kao et al., 1999, Messer et al., 2009, San Miguel et al., 2005, Silva et al., 2004, Tortorano et al., 2004, Trick et al., 2002). But, most of the data on candidemia in Spain until recent days are limited to retrospective reviews of medical records or observational studies conducted in a limited geographical area (Almirante et al., 2005, Alonso-Valle et al., 2003, Pemán et al., 2002, Pemán et al., 2011). Regarding the Spanish data available on antifungal resistance is often assessed by occasional surveys or reported in summaries of sporadically occurring cases of treatment failures. The purpose of such investigations is to monitor levels of susceptibility to different agents. However, long-term prospective studies of antifungal susceptibility have the advantage of eliminating a number of variable factors which may affect these assessments. Some of these factors include temporary changes in patterns of Invasive Candida infections (as stated before) and transient alterations in antifungal resistance due to special conditions (e.g. candidemia outbreaks in ICUs). Consequently, the epidemiological data about candidemia and its impact in the healthcare system is unknown, and no reliable nationwide data are available. In order to make a realistic global perspective of invasive Candida BSI, we designed a prospective laboratory-based surveillance study comprising 40 tertiary care hospitals across the country, to assess the incidence, species distribution, frequency of antifungal resistance, and risk factors for candidemia.