population, other than people with gluten-related disorders or other associated conditions which improve with a gluten-free diet in some cases, such as irritable bowel syndrome and certain autoimmune and neurological disorders. there is no published experimental evidence to support that the gluten-free diet contributes to weight loss. in a review of may 2015 published in gastroenterology, fasano et al. conclude that, although there is an evident "fad component" to the recent rise in popularity of the gluten-free diet, there is also growing and unquestionable evidence of the existence of non-coeliac gluten sensitivity. in some cases, the popularity of the gluten-free diet may harm people who must eliminate gluten for medical reasons. for example, servers in restaurants may not take dietary requirements seriously, believing them to be merely a preference. this could prevent appropriate precautions in food handling to prevent gluten cross-contamination. medical professionals may also confuse medical explanations for gluten intolerance with patient preference. on the other hand, the popularity of the gluten-free diet has increased the availability of commercial gluten-free replacement products and gluten-free grains. gluten-free commercial replacement products, such as gluten-free cakes, are more expensive than their gluten-containing counterparts, so their purchase adds a financial burden. they are also typically higher in calories, fat, and sugar, and lower in dietary fibre. in less developed countries, wheat can represent an important source of protein, since it is a substantial part of the diet in the form of bread, noodles, bulgur, couscous, and other products. in the british national health service, gluten-free foods have been supplied on prescription. for many patients, this meant at no cost. when it was proposed to alter this in 2018, the department of health and social care made an assessment of the costs and benefits. the potential annual financial saving to the service was estimated at £5.3 million, taking into account the reduction in cost spending and the loss of income from prescription charges. the proposed scenario was actually that patients could still be prescribed gluten-free breads and mixes but would have to buy any other gluten-free products themselves. the savings would only amount to £700,000 a year. local initiatives by clinical commissioning groups had already reduced the cost of gluten-free foods to the nhs by 39% between 2015 and 2017. healthcare professionals recommend against undertaking a gluten-free diet as a form of self-diagnosis, because tests for coeliac disease are reliable only if the person has been consuming gluten recently. there is a consensus in the medical community that people should consult a physician before going on a gluten-free diet, so that a medical professional can accurately test for coeliac disease or any other gluten-induced health issues. although popularly used as an alternative treatment for people with autism, there is no good evidence that a gluten-free diet is of benefit in reducing the symptoms of autism. research in a 2013 double-blind, placebo-controlled challenge (dbpc) by biesiekierski et al. in a few people with irritable bowel syndrome, the authors found no difference between gluten or placebo groups and the concept of non-celiac gluten sensitivity as a syndrome was questioned. nevertheless, this study had design errors and an incorrect selection of participants, and probably the reintroduction of both gluten and whey protein had a nocebo effect similar in all people, and this could have masked the true effect of gluten/wheat reintroduction. in a 2015 double-blind placebo cross-over trial, small amounts of purified wheat gluten triggered gastrointestinal symptoms (such as abdominal bloating and pain) and extra-intestinal manifestations (such as foggy mind, depression and aphthous stomatitis) in self-reported non-celiac gluten sensitivity. nevertheless, it remains elusive whether these findings specifically implicate gluten or other proteins present in gluten-containing cereals. in a 2018 double-blind, crossover research study on 59 persons on a gluten-free diet with challenges of gluten, fructans or placebo, intestinal symptoms (specifically bloating) were borderline significantly higher after challenge with fructans, in comparison with gluten proteins (p=0.049). although the differences between the three interventions was very small, the authors concluded that fructans (the specific type of fodmap found in wheat) are more likely to be the cause of gastrointestinal symptoms of non-celiac gluten sensitivity, rather than gluten. for this previous study, experts recommend a low fodmap diet instead of a gluten free diet for those patients suffering of functional gastrointestinal disorders as bloating. in addition, fructans used in the study were extracted from chicory root, so it remains to be seen whether the wheat fructans produce the same effect. eating gluten-free quinoa is a pseudocereal that is gluten-free. gluten-free bread made of a mixture of flours like buckwheat flour, tapioca flour, millet flour and psyllium seed husks. special flour mixes can be bought for bread-making purposes. a gluten-free diet is a diet that strictly excludes gluten, proteins present in wheat (and all wheat varieties such as spelt and kamut), barley, rye, oat, and derivatives of these grains such as malt and triticale, and foods that may include them, or shared transportation or processing facilities with them. the inclusion of oats in a gluten-free diet remains controversial. oat toxicity in people with gluten-related disorders depends on the oat cultivar consumed because the immunoreactivities of toxic prolamins are different among oat varieties. furthermore, oats are frequently cross-contaminated with the other gluten-containing cereals. pure oat (labelled as "pure oat" or "gluten-free oat") refers to oats uncontaminated with any of the other gluten-containing cereals. some cultivars of pure oat could be a safe part of a gluten-free diet, requiring knowledge of the oat variety used in food products for a gluten-free diet. nevertheless, the long-term effects of pure oats consumption are still unclear and further studies identifying the cultivars used are needed before making final recommendations on their inclusion in the gluten-free diet. other grains, although gluten-free in themselves, may contain gluten by cross-contamination with gluten-containing cereals during grain harvesting, transporting, milling, storing, processing, handling or cooking. processed foods commonly contain gluten as an additive (as emulsifiers, thickeners, gelling agents, fillers, and coatings), so they would need specific labeling. unexpected sources of gluten are, among others, processed meat, vegetarian meat substitutes, reconstituted seafood, stuffings, butter, seasonings, marinades, dressings, confectionary, candies, and ice cream. gluten-free rice flour cross-contamination in the home is also a consideration for those who have gluten-related disorders. there can be many sources of cross-contamination, as for example when family members prepare gluten-free and gluten-containing foods on the same surfaces (countertops, tables, etc.) or share utensils that have not been cleaned after being used to prepare gluten-containing foods (cutting boards, colanders, cutlery, etc.), kitchen equipment (toaster, cupboards, etc.) or certain packaged foods (butter, peanut butter, etc.). a grocery store's aisle of gluten-free food items. restaurants prove to be another source of cross-contamination for those following a strict gluten-free diet. a study conducted by columbia university medical center found that 32% of foods labeled gluten-free at restaurants contain above 20 parts per million of gluten, meaning that it contains enough gluten that it is no longer considered gluten-free by the codex alimentarius. cross-contamination occurs in these areas frequently because of a general lack of knowledge about the needed level of caution and the prevalence of gluten in restaurant kitchens. if cooks are unaware of the severity of their guest's diet restrictions or of the important practices needed to limit cross-contamination, they can unknowingly deliver contaminated food. however, some restaurants utilize a training program for their employees to educate them about the gluten-free diet. the accuracy of the training varies. one resource to find these safer restaurants is an app and website called "find me gluten free" that allows people following a gluten-free diet to rate the safety of different restaurants from their point of view and describe their experience to help future customers. easily locating gluten-free items is one of the main difficulties in following a gluten-free diet. to assist in this process, many restaurants and grocery stores choose to label food items. restaurants often add a gluten-free section to their menu, or specifically mark gluten-free items with a symbol of some kind. grocery stores often have a gluten-free aisle, or they will attach labels on the shelf underneath gluten-free items. though the food is labeled gluten-free in this way, it doesn't necessarily mean that the food is safe for those with gluten-related disorders, as a compilation of studies suggest. medications and dietary supplements are made using excipients that may contain gluten. the gluten-free diet includes naturally gluten-free food, such as meat, fish, seafood, eggs, milk and dairy products, nuts, legumes, fruit, vegetables, potatoes, pseudocereals (in particular amaranth, buckwheat, chia seed, quinoa), only certain cereal grains (corn, rice, sorghum), minor cereals (including fonio, job's tears, millet, teff, called "minor" cereals as they are "less common and are only grown in a few small regions of the world"), some other plant products (arrowroot, mesquite flour, sago, tapioca) and products made from these gluten-free foods. most indian cuisine options, particularly south indian cuisine, are for the most part inherently gluten-free and in fact most indian vegetarian options are inherently vegan. risks an unbalanced selection of food and an incorrect choice of gluten-free replacement products may lead to nutritional deficiencies. replacing flour from wheat or other gluten-containing cereals with gluten-free flours in commercial products may lead to a lower intake of important nutrients, such as iron and b vitamins and a higher intake of sugars and saturated fats. some gluten-free commercial replacement products are not enriched or fortified as their gluten-containing counterparts, and often have greater lipid / carbohydrate content. children especially often over-consume these products, such as snacks and biscuits. these nutritional complications can be prevented by a correct dietary education. pseudocereals (quinoa, amaranth, and buckwheat) and some minor cereals are healthy alternatives to these prepared products and have higher biological and nutritional value. advances towards higher nutrition-content gluten-free bakery products, improved for example in terms of fiber content and glycemic index, have been made by using not exclusively corn starch or other starches to substitute for flour. in this aim, for example the dietary fibre inulin (which acts as a prebiotic) or quinoa or amaranth wholemeal have been as substitute for part of the flour. similarly, xanthan gum can be used in up to gram quantities per serving in some gluten-free baked goods and can be fermented by specific microbiomes in the gastrointestinal tract. such substitution has been found to also yield improved crust and texture of bread. it is recommended that anyone embarking on a gluten-free diet check with a registered dietitian to make sure they are getting the required amount of key nutrients like iron, calcium, fiber, thiamin, riboflavin, niacin and folate. vitamins often contain gluten as a binding agent. experts have advised that it is important to always read the content label of any product that is intended to be swallowed. up to 30% of people with known coeliac disease often continue having or redeveloping symptoms. also, a lack of symptoms or negative blood antibodies levels are not reliable indicators of intestinal recuperation. several studies show an incomplete recovery of small bowel despite a strict gluten-free diet, and about 79% of such people have persistent villous atrophy. this lack of recovery is mainly caused by inadvertent exposure to gluten. people with poor basic education and understanding of the gluten-free diet often believe that they are strictly following the diet, but are making regular errors. in addition, some people often deliberately continue eating gluten because of limited availability, inferior taste, higher price, and inadequate labelling of gluten-free products. poor compliance with the regimen is also influenced by age at diagnosis (adolescents), ignorance of the consequences of the lack of a strict treatment and certain psychological factors. ongoing gluten intake can cause severe disease complications, such as various types of cancers (both intestinal and extra-intestinal) and osteoporosis. regulation and labels the term gluten-free is generally used to indicate a supposed harmless level of gluten rather than a complete absence. the exact level at which gluten is harmless is uncertain and controversial. a 2008 systematic review tentatively concluded that consumption of less than 10 mg (10 ppm) of gluten per day is unlikely to cause histological abnormalities, although it noted that few reliable studies had been done. regulation of the label gluten-free varies by country. most countries derive key provisions of their gluten-free labelling regulations from the codex alimentarius international standards