The serum LDL/HDL cholesterol ratio is influenced more favorably by exchanging saturated with unsaturated fat than by reducing saturated fat in the diet of women. Changes in plasma lipids and other cardiovascular risk factors during 3 energy-restricted diets differing in total fat and fatty acid composition. Separate effects of reduced carbohydrate intake and weight loss on atherogenic dyslipidemia. Substitution of saturated with monounsaturated fat in a 4-week diet affects body weight and composition of overweight and obese men. High-oleic peanuts: new perspective to attenuate glucose homeostasis disruption and inflammation related obesity. Effect of a high monounsaturated fatty acids diet and a Mediterranean diet on serum lipids and insulin sensitivity in adults with mild abdominal obesity. The effect of the plasma n-3/n-6 polyunsaturated fatty acid ratio on the dietary LDL phenotype transformation - insights from the LIPGENE study. We need more randomized trials in nutrition-preferably large, long-term, and with negative results.
We compared the effects of a high fat diet [ 38.4 % of energy ( E% ) from fat ; HSAFA diet , polyunsaturated/saturated fatty acid ( P/S ) ratio = 0.14 ] , a low fat diet ( 19.7 E% from fat ; LSAFA diet , P/S = 0.17 ) , both based on coconut oil , and a diet with a high content of mono- and polyunsaturated fatty acids ( PUFA ; 38.2 E% from fat ; HUFA diet , P/S = 1.9 ) on serum lipoproteins . The 25 women studied consumed each diet for 3-wk periods in a crossover design . The two high fat diets were identical except for the quality of the test fat . The LSAFA diet was identical to the HSAFA diet except that half the fat was replaced by carbohydrates . Serum total cholesterol , LDL cholesterol and apoB concentrations did not differ between the HSAFA and the LSAFA diet periods . Total cholesterol , LDL cholesterol and apoB were lower when women consumed the HUFA diet than when they consumed the other two diets . HDL cholesterol and apoA-I were 15 and 11 % , respectively , higher when women consumed the HSAFA diet than when they consumed the LSAFA diet ;  HDL cholesterol and apoA-I were lower when women consumed the HUFA diet than when they consumed the HSAFA diet , but not the LSAFA diet .  The LDL cholesterol/HDL cholesterol and apoB/apoA-I ratios were higher when women consumed the LSAFA diet than when they consumed the HSAFA diet . The LDL/HDL cholesterol ratio was higher when women consumed either the LSAFA or the HSAFA diet than when they consumed the HUFA diet , whereas apoB/apoA-I was higher when women consumed the LSAFA diet than when they consumed the HUFA diet . Triacylglycerol and VLDL cholesterol were higher when women consumed the LSAFA diet than when they consumed either the HSAFA or the HUFA diet . We conclude that , to influence the LDL/HDL cholesterol ratio , changing the proportions of dietary fatty acids may be more important than restricting the percentage of total or saturated fat energy , at least when derived mainly from lauric and myristic acids , both of which increase HDL cholesterol BACKGROUND The well-established relation between changes in dietary fatty acids and plasma lipids has been determined in energy-balance states . Whether this relation is altered in states of energy restriction and active weight loss is not clear . OBJECTIVE The objective of this 12-wk study was to compare the time course of lipid changes and other cardiovascular risk factors in 3 energy-restricted diets ( all 6500 kJ ) with different total fat and fatty acid compositions . DESIGN Sixty-two subjects with a body mass index ( in kg/m(2 ) ) > 24 were stratified into 1 of 3 parallel dietary intervention groups : 1 ) a very-low-fat ( VLF ) diet ( 10 % of energy from fat ; 3 % from saturated fat ) , 2 ) a high-saturated-fat ( HSF ) diet ( 32 % of energy from fat ; 17 % from saturated fat ) , and 3 ) a high-unsaturated-fat ( HUF ) diet ( 32 % of energy from fat ; 6 % from saturated fat ) . RESULTS After 12 wk , LDL cholesterol decreased by 0 . 66 + /- 0.11 ( mean + /- SEM ) and 0.68 + /- 0.12 mmol/L ( approximately 20 % ) with the VLF and HUF diets , respectively , compared with a decrease of only 0.24 + /- 0.11 mmol/L ( 7 % ) with the HSF diet ( P < 0.02 between groups ) . Diet affected the time course of changes in HDL cholesterol with both high-fat diets , result ing in smaller reductions in HDL cholesterol at weeks 1 ( P = 0.0004 ) and 4 ( P = 0.02 ) ; however , these differences were no longer apparent by 12 wk . Overall weight loss was 8.6 + /- 0.4 kg ( 9.7 % ) and waist circumference decreased by 7.3 + /- 5 cm ( 8 % ) for the combined groups , with no significant differences between diets . CONCLUSIONS Significantly greater decreases in LDL cholesterol during active weight loss are achieved with diets low in saturated fatty acids . Changes in HDL cholesterol between diets appear dependent on both the fat content of the diet and the duration of energy restriction BACKGROUND Low-carbohydrate diets have been used to manage obesity and its metabolic consequences . OBJECTIVE The objective was to study the effects of moderate carbohydrate restriction on  atherogenic dyslipidemia before and after weight loss and in conjunction with a low or high dietary saturated fat intake . DESIGN After 1 wk of consuming a basal diet , 178 men with a mean body mass index ( in kg/m(2 ) ) of 29.2 + /- 2.0 were r and omly assigned to consume diets with carbohydrate contents of 54 % ( basal diet ) , 39 % , or 26 % of energy and with a low saturated fat content ( 7 - 9 % of energy ) ; a fourth group consumed a diet with 26 % of energy as carbohydrate and 15 % as saturated fat . After 3 wk , the mean weight loss ( 5.12 + /- 1.83 kg ) was induced in all diet groups by a reduction of approximately 1000 kcal/d for 5 wk followed by 4 wk of weight stabilization . RESULTS The 26%-carbohydrate , low-saturated-fat diet reduced triacylglycerol , apolipoprotein B , small LDL mass , and total : HDL cholesterol and increased LDL peak diameter . These changes were significantly different from those with the 54%-carbohydrate diet . After subsequent weight loss , the changes in all these variables were significantly greater and the reduction in LDL cholesterol was significantly greater with the 54%-carbohydrate diet than with the 26%-carbohydrate diet . With the 26%-carbohydrate diet , lipoprotein changes with the higher saturated fat intakes were not significantly different from those with the lower saturated fat intakes , except for LDL cholesterol , which decreased less with the higher saturated fat intake because of an increase in mass of large LDL . CONCLUSIONS Moderate carbohydrate restriction and weight loss provide equivalent but nonadditive approaches to improving atherogenic dyslipidemia . Moreover , beneficial lipid changes result ing from a reduced carbohydrate intake were not significant after weight loss A r and omised crossover study of eight overweight or obese men ( aged 24 - 49 years , BMI 25.5 - 31.3 kg/m(2 ) ) , who followed two diets for 4 weeks each , was performed to determine whether substitution of saturated fat with monounsaturated fat affects body weight and composition . Subjects were provided with all food and beverages as modules ( selected ad libitum ) of constant macronutrient composition , but differing energy content . The % total energy from saturated fat , monounsaturated fat and polyunsaturated fat was 24 , 13 and 3 % respectively on the saturated fatty acid (SFA)-rich diet and 11 , 22 and 7 % respectively on the monounsaturated fatty acid (MUFA)-rich diet . MUFA accounted for about 80 % of the unsaturated fats consumed on both diets . Body composition , blood pressure , energy expenditure ( resting and postpr and ial metabolic rates , substrate oxidation rate , physical activity ) , serum lipids , the fatty acid profile of serum cholesteryl esters and plasma glucose and insulin concentrations were measured before and after each diet period . Significant ( P < or = 0.05 ) differences in total cholesterol and the fatty acid composition of serum cholesteryl esters provided evidence of dietary adherence . The men had a lower weight ( -2.1 ( SE 0.4 ) kg , P=0.0015 ) and fat mass ( -2.6 ( SE 0.6 ) kg , P=0.0034 ) at the end of the MUFA-rich diet as compared with values at the end of the SFA-rich diet . No significant differences were detected in energy or fat intake , energy expenditure , substrate oxidation rates or self-reported physical activity . Substituting dietary saturated with unsaturated fat , predominantly MUFA , can induce a small but significant loss of body weight and fat mass without a significant change in total energy or fat intake OBJECTIVE To evaluate the effects of acute and daily consumption of high-oleic peanuts ( HOP ) on inflammation and glucose homeostasis in overweight/obese men . METHODS In a 4-week r and omized clinical trial , males with body mass index of 29.8 ± 2.3 kg/m(2 ) and aged 18 - 50 years were assigned to the groups : control ( CT , n = 22 ) ; conventional peanuts ( CVP , n = 22 ) ; or HOP ( n = 21 ) . They followed a hypocaloric-diet with or without 56 g/day of CVP or HOP . Main outcomes were changes in fasting blood biomarkers and postpr and ial insulin , glucose , tumor necrosis factor-alfa ( TNF-α ) , and interleukin-10 ( IL-10 ) responses after acute peanut intake . RESULTS At baseline , HOP showed significantly lower postpr and ial responses of glucose , insulin , and TNF-α than CVP and CT . Changes in fasting blood biomarkers did not differ between groups after the 4-week intervention . However , within groups , total cholesterol decreased in CT , and all groups reduced High-density lipoprotein ( HDL-c ) . Triglycerides were reduced in HOP and CVP . IL-10 increased significantly in all groups while only the CT and CVP showed increased TNF-α after intervention . CONCLUSION Acute high-oleic peanut consumption leads to stronger moderation of postpr and ial glucose , insulin , and TNF-α concentrations than CVP and control meal intake . Whether daily intake of high-oleic peanuts has additional benefits to CVP remains uncertain BACKGROUND AND AIMS Diets high in monounsaturated fatty acids ( MUFA ) such as a Mediterranean diet may reduce the risk of cardiovascular diseases by improving insulin sensitivity and serum lipids . Besides being high in MUFA , a Mediterranean diet also contains abundant plant foods , moderate wine and low amounts of meat and dairy products , which may also play a role . We compared the effects of a high MUFA-diet with a diet high in saturated fatty acids ( SFA ) and the additional effect of a Mediterranean diet on insulin sensitivity and serum lipids . METHODS AND RESULTS A r and omized parallel controlled-feeding trial was performed , in 60 non-diabetics ( 40 - 65 y ) with mild abdominal obesity . After a two week run-in diet high in SFA ( 19 energy-% ) , subjects were allocated to a high MUFA-diet ( 20 energy-% ) , a Mediterranean diet ( MUFA 21 energy-% ) , or the high SFA-diet , for eight weeks . The high MUFA and the Mediterranean diet did not affect fasting insulin concentrations . The high MUFA-diet reduced total cholesterol ( -0.41 mmol/L , 95 % CI -0.74 , -0.09 ) and LDL-cholesterol ( -0.38 mmol/L , 95 % CI -0.65 , -0.11 ) compared with the high SFA-diet , but not triglyceride concentrations . The Mediterranean diet increased HDL-cholesterol concentrations ( + 0.09 mmol/L , 95 % CI 0.0 , 0.18 ) and reduced the ratio of total cholesterol/HDL-cholesterol ( -0.39 , 95 % CI -0.62 , -0.16 ) compared with the high MUFA-diet . CONCLUSION Replacing a high SFA-diet with a high MUFA or a Mediterranean diet did not affect insulin sensitivity , but improved serum lipids . The Mediterranean diet was most effective , it reduced total and LDL-cholesterol , and also increased HDL-cholesterol and reduced total cholesterol/HDL-cholesterol ratio BACKGROUND & AIMS LDL phenotype B is associated with obesity , insulin resistance , hypertriglyceridemia and oxidative stress . The effect of plasma n-3/n-6 PUFA ratio on LDL phenotype transformation was investigated . METHODS Patients with metabolic syndrome ( n=99 ) received one of four isocaloric diets : ( A ) High-fat ( 38 % energy ) SFA-rich diet ( HSFA ) ; ( B ) High-fat ( 38 % energy ) , MUFA-rich diet ( HMUFA ) ; ( C ) , low-fat ( LF ) ( 28 % energy ) , high-complex carbohydrate diet with 1.24g/d oleic sunflower oil ( LFHCC ) and ( D ) : low-fat ( 28 % energy ) , high-complex carbohydrate diet , with 1.24g/d LC n-3 PUFA ( LFHCC n-3 ) for 12 weeks . Analysis of plasma lipid profile and LDL phenotype was done pre- and post- interventions . RESULTS Post-dietary change of LDL density was a main effect observed in all groups . LFHCC n-3 and HFMUFA diets result ed in favorable alteration of LDL phenotype from B to A and decreased LDL density . In contrast , increased LDL density was observed in HSFA and LFHCC groups . The plasma pre-n3/n6 PUFA , Apo E change and pre-Apo CIII/CII ratios explained in 65 % the post-dietary change of LDL density in diet LFHCC n-3 consumers . CONCLUSIONS Study demonstrates efficacy of dietary n-3 PUFA to modify pro-atherogenic to less atherogenic LDL phenotype in patients with metabolic syndrome . Study identifier at Clinical Trials.gov was NCT00429195 The key to optimal nutrition choices has been sought mostly in tens of thous and s of observational analyses as well as in expert editorials ( like mine ) and recommendations . Epidemiology and opinion grossly outnumber r and omized trials in this important field . Therefore , having 4 r and omized trials of nutrition interventions published in the same issue of the Journal is an opportunity for celebration . It is even more rewarding that 3 of these trials have sample sizes .100 ( and 1 trial has a sample size .1500 ) and 2 have long-term follow-up . The best news is that all 4 trials have “ negative ” results for some or all primary outcomes .  DHA supplementation during pregnancy did not reduce BMI or fat mass in children  at aged 5 y ( 1 ) . A reduction in the n–6:n–3 long-chain PUFA ratio during pregnancy and lactation had no major impact on offspring body composition after 5 y ( 2 ) . A trial of amino acid regimen and intravenous lipid composition in preterm parenteral nutrition showed largely nonsignificant differences between compared regimens ( 3 ) . Finally , a small trial that compared fructose , sucralose , and sucrose acute effects after solid meals showed no differences in triglyceride concentrations ( 4 ) . Admittedly , this last trial also showed significant differences in other outcomes . Although I would have preferred purely “ negative ” results , my disappointment is tempered , because the “ positive ” results pertained to physiologic rather than to major clinical outcomes . R and omized trials have had a rough time establishing themselves in nutrition research . Influential epidemiologists have expressed skepticism about r and omized trials for nutrition or lifestyle interventions in general ( e.g. , reference 5 ) . Nonr and omized observational studies have been favored because people change their choices ; thus , crossover , cross-in , withdrawals , and poor adherence are considered impediments for clinical trials , and the estimation of effect sizes by intention-to-treat may misrepresent the mechanistic effects . These arguments are actually some of the reasons why r and omized trials are not only preferable but also can not be replaced by epidemiologic studies . Experiments are needed to study mechanisms and acute-change physiology , and the best way to perform well-controlled experiments is by r and omization . Responses can be evaluated accurately with short-term data collection for physiologic changes . For studies that aim to assess long-term outcomes with clinical portend , epidemiologic studies are just too unreliable to capture subtle treatment effects whenever noise due to confounding and other biases exceeds plausible signals . For most clinical outcomes ( as opposed to physiology or surrogate outcomes ) , the magnitude of the treatment effects of nutritional interventions is probably small or modest ( 6 ) . Adherence , withdrawals , and treatment fidelity problems are not necessarily insurmountable and methods exist to improve retention ( 7 ) . Moreover , any useful intervention should have mechanistic efficacy but should also be tolerable enough that people can adhere to it . If an intervention is mechanistically efficacious but can not be used long term , it is practically the same as if it lacked efficacy to start with . The combination of small effect sizes and unknown adherence means that these questions can only be addressed reliably with large , well-powered studies and long-term follow-up . Chasing small or modest effects with underpowered , small studies is an ideal recipe for getting both false-negative and even more falsepositive results ( 8) . Long-term follow-up is necessary both for increasing the power for patient-relevant clinical events as well as for making the results relevant for real life . People care mostly about what nutrition can achieve for them in the long term , not just whether they can improve some metabolic variables or their weight for a few months . In this setting , “ negative ” results are much more desirable than “ positive ” ones . Let me explain this paradox . First , many “ negative ” results are not failures to show the superiority of 1 nutritional intervention compared with another but offer evidence of noninferiority or equivalence . They mean that different nutrition choices lead to equally acceptable outcomes . This is great news : it is better to have many equally good choices on what to eat than just one . Second , other “ negative ” results indeed show that nutrients or diets that we thought would be effective ( e.g. , on the basis of observational epidemiology ) are not . The information gain ( informativity , entropy change ) from the results of any study depends on how much the study changes our
Background : Obesity and dyslipidemia are frequently treated with dietary interventions before pharmacotherapy is given .
Diets high in unsaturated fat have proven advantageous to disease treatment .
Aims : The purpose of this systematic review and meta- analysis was to assess the evidence of the effect of saturated fatty acids ( SFA ) replacement with unsaturated fatty acids ( UFA ) in metabolically healthy adults with overweight and obesity on markers of dyslipidemia and body composition .