Louise Corneau

Lack of effect of dietary conjugated linoleic acids naturally incorporated into butter on the lipid profile and body composition of overweight and obese men

BACKGROUND Dietary conjugated linoleic acid (CLA) is known to reduce atherosclerosis, plasma total and LDL-cholesterol concentrations, and body fat accumulation in several animal species. Of the few studies that investigated the effects of CLA supplementation in humans, all used commercially formulated oral supplements made from a mixture of CLA isomers. OBJECTIVE We compared the effects on plasma lipoproteins and body composition of the consumption of a modified butter naturally enriched with CLA (CLA-B: 4.22 g CLA/100 g butter fat) by the addition of sunflower oil to the diet of dairy cows with the consumption of a control butter (CON-B) that was low in CLA (0.38 g CLA/100 g butter fat). DESIGN In a crossover design study including an 8-wk washout period, 16 men [x +/- SD age: 36.6 +/- 12.4 y; body mass index (in kg/m2): 31.2 +/- 4.4] were fed each of the 2 experimental isoenergetic diets, providing 15% of energy as protein, 45% as carbohydrates, and 40% as lipids, of which >60% was derived from experimental fats, for 4 wk. RESULTS Consumption of the CLA-B diet induced a significantly (P < 0.05) smaller reduction in plasma total cholesterol and in the ratio of total to HDL cholesterol (-0.02 mmol/L and -0.00, respectively) than did consumption of the CON-B diet (-0.26 mmol/L and-0.34, respectively). Abdominal adipose tissue area measured by computed tomography showed no difference in accumulation of either visceral or subcutaneous adipose tissue after the 2 experimental diets. CONCLUSION These results suggest that a 10-fold CLA enrichment of butter fat does not induce beneficial metabolic effects in overweight or obese men.

Health-At-Every-Size and Eating Behaviors: 1-Year Follow-Up Results of a Size Acceptance Intervention

BACKGROUND Poor long-term success observed with current weight-control strategies stresses the relevance to explore new weight management approaches. OBJECTIVE To assess the effects of a Health-At-Every-Size (HAES) intervention on eating behaviors, appetite sensations, metabolic and anthropometric variables, and physical activity levels in women at 6-month and 1-year postintervention. DESIGN Randomized controlled trial; measurements at baseline, at the end of the intervention period (4 months), and at 6-month and 1-year postintervention (10 months and 16 months, respectively). Intervention and testing took place from September 2003 to August 2006. PARTICIPANTS/SETTING Premenopausal overweight/obese women (n=144; mean age of 42.3+/-5.6 years), recruited from free-living, general community. INTERVENTION Women were randomly assigned to: HAES group (n=48), social support group (n=48), or control group (n=48). MAIN OUTCOME MEASURES Eating behaviors (restraint, disinhibition, and susceptibility to hunger), appetite ratings (desire to eat, hunger, fullness, and prospective food consumption), anthropometric and metabolic variables (body mass index, waist and hip circumferences, blood lipid levels, and blood pressure), and engagement in moderate to intense physical activity (energy cost > or =1.2 k cal x kg(-1) x 15 minutes(-1) [> or =4.8 metabolic equivalents]). STATISTICAL ANALYSES PERFORMED Changes for each dependent variable were assessed by linear mixed models according to a group (HAES vs social support vs control) by time (baseline vs 4 months vs 10 months vs 16 months) split-plot design. RESULTS Situational susceptibility to disinhibition and susceptibility to hunger significantly decreased over time in both HAES group (-0.9+/-0.2 and -1.3+/-0.5, respectively) and the social support group (-0.4+/- 0.2 and -1.4+/-0.5, respectively). Although eating behavior scores observed at 16 months did not differ between HAES and social support groups (situational susceptibility to disinhibition: 2.5+/-0.2 in HAES group vs 2.7 +/- 0.2 in social support group; susceptibility to hunger: 4.2+/-0.5 in both groups), they were lower in these groups than scores noted in the control group (3.3+/-0.2 for situational susceptibility to disinhibition and 5.9+/-0.5 for susceptibility to hunger). CONCLUSIONS These results suggest that, when compared to a control group, an HAES approach could have long-term beneficial effects on eating behaviors related to disinhibition and hunger. In addition, our study did not show distinctive effects of the HAES approach in comparison to a social support intervention.

Regional body fat distribution and metabolic profile in postmenopausal women

The aim of the study was to examine how body fat distribution variables were associated with metabolic parameters in a sample of 113 postmenopausal women not receiving hormone therapy (56.9 +/- 4.4 years, 28.4 +/- 5.1 kg/m(2)). Body fat distribution variables (visceral adipose tissue [AT], subcutaneous AT, and total midthigh AT) were measured using computed tomography; body fat mass was assessed by hydrostatic weighing; insulin sensitivity was determined with the euglycemic-hyperinsulinemic clamp; fasting plasma glucose (FPG) and 2-hour plasma glucose (2hPG) concentrations were measured by a 75-g oral glucose load; and (high-sensitivity) C-reactive protein (hs-CRP) was measured using a highly sensitive assay. After controlling for fat mass, visceral AT was positively associated with plasma triglyceride, hs-CRP, FPG, and 2hPG, and negatively associated with high-density lipoprotein cholesterol (HDL-C) and insulin sensitivity. Total midthigh AT was negatively associated with apolipoprotein B, FPG, and 2hPG, and positively associated with insulin sensitivity. Stepwise multiple regression analyses including abdominal visceral AT, subcutaneous AT and total midthigh AT as independent variables showed that abdominal visceral AT best predicted the variance in plasma triglyceride, HDL-C, low-density lipoprotein peak particle size, hs-CRP, FPG, 2hPG, and insulin sensitivity. Abdominal subcutaneous AT was a significant predictor of only insulin sensitivity, whereas total midthigh AT predicted HDL-C, low-density lipoprotein peak particle size, and apolipoprotein B. These multivariate analyses also indicated that total midthigh AT was favorably related to these outcomes, whereas abdominal visceral AT and subcutaneous AT were unfavorably related. These results confirmed that abdominal visceral fat is a critical correlate of metabolic parameters in postmenopausal women. In addition, a higher proportion of AT located in the total midthigh depot is associated with a favorable metabolic profile.

Sex differences in the impact of the Mediterranean diet on cardiovascular risk profile

The traditional Mediterranean diet (MedDiet) is now widely recommended in the prevention of CVD. However, it is not known whether the MedDiet has the same beneficial cardiovascular effects in women and in men. The objective of the present study was to investigate sex-related differences with regard to changes in cardiometabolic variables in response to a 4-week isoenergetic MedDiet. Participants were thirty-eight men and thirty-two premenopausal women aged between 25 and 50 years who had slightly elevated LDL-cholesterol (LDL-C) concentrations (3·4-4·9 mmol/l) or total cholesterol:HDL-cholesterol ratio ≥ 5·0. A 4-week run-in period preceded the MedDiet in order to control the inter- and intra-individual variability. Cardiometabolic variables were measured before and after the MedDiet. Total cholesterol, LDL-C, apoB and apoA-1 plasma concentrations as well as diastolic blood pressure decreased (P < 0·05) in both men and women (respectively, 10, 10, 10, 6 and 5% for men and 6, 7, 9, 4 and 4% for women). ApoA-2 concentrations and insulin concentrations 2 h after the oral administration of 75 g of glucose demonstrated sex × time interactions (respectively, P = 0·05 and P = 0·03) and only men experienced a decrease for these variables (respectively, 8 and 25%). In conclusion, consuming a MedDiet led to significant changes in plasma lipid profile in both men and women, while only men had significant improvements in insulin homeostasis. These results support the importance of investigating sex-related differences in response to diet in order to perhaps further individualise dietary guidelines in the prevention of CVD and type 2 diabetes.

Impact of a health-at-every-size intervention on changes in dietary intakes and eating patterns in premenopausal overweight women : results of a randomized trial

BACKGROUND & AIMS Previous studies have shown improvements in eating behaviors following a Health-At-Every-Size approach (HAES). However, to our knowledge, no study has yet investigated how a HAES intervention could influence dietary intakes and eating patterns in overweight women. Therefore, objectives of this study were to determine changes in dietary intakes and eating patterns in premenopausal overweight women in response to a HAES intervention compared to a social support intervention and a control group, and then to determine whether changes in eating behaviors were associated with changes in dietary intakes and eating patterns in response to the HAES intervention. METHODS Women completed a 3-day food record and the Three-Factor Eating Questionnaire was used to assess eating behaviors. RESULTS Energy intake (main effect of time; p = 0.045) and snack frequency (main effect of time; p = 0.0004) decreased similarly over time in the three groups whereas proportion of energy intake from breakfast (main effect of time; p = 0.03) increased over time. Within HAES group, decreases in hunger and external hunger were associated with a decrease in total daily energy intake (r = 0.50, p = 0.0009 and r = 0.50, p = 0.0007, respectively). CONCLUSIONS HAES intervention has no specific impact on eating patterns. However, a decrease in hunger, which characterizes women who respond well to HAES, is associated with a decrease in overall energy intake. Clinical trial registration number (www.clinicaltrials.gov): NCT01240499.

Gender differences in dietary intakes: what is the contribution of motivational variables?

BACKGROUND Differences between men and women with respect to dietary intakes and eating behaviours have been reported and could be explained by gender differences in motivational variables associated with the regulation of food intake. The main objectives of the present study were to identify gender differences in dietary intakes, eating behaviours and motivational variables and to determine how motivational variables were associated with dietary intakes and eating behaviours in men and women. METHODS Sixty-four men and 59 premenopausal women were included in the present study and presented cardiovascular risk factors. The Regulation of Eating Behaviours scale was completed to assess motivational variables. A validated food frequency questionnaire was administered to evaluate dietary intakes and subjects completed the Three-Factor Eating questionnaire to assess eating behaviours. RESULTS Men had higher energy intake, energy density and percentage of energy from lipids and lower percentage of energy from carbohydrates than women (P ≤ 0.04). Men also had a lower emotional susceptibility to disinhibition than women (P = 0.0001). Women reported a higher score for eating-related self-determined motivation [i.e., eating-related self-determination index (SDI)] than men (P = 0.002). The most notable gender difference in the pattern of associations was that eating-related SDI was negatively associated with energy density (r = -0.30; P = 0.02), only in women. CONCLUSIONS Women had a better dietary profile and higher eating-related SDI than men. However, gender differences in dietary variables might be explained by a potential gender-specific pattern of association of eating-related SDI with dietary intakes and eating behaviours.

Gender differences in the long-term effects of a nutritional intervention program promoting the Mediterranean diet: changes in dietary intakes, eating behaviors, anthropometric and metabolic variables

BackgroundLong-term adherence to principles of the Mediterranean diet (MedDiet) following a nutritional intervention promoting the Mediterranean food pattern in Canadian men and women is not known. Moreover, gender differences in dietary and metabolic profile in such an intervention context has never been addressed. Objective was to determine gender differences in long-term effects of a 12-week nutritional intervention program promoting the adoption of the MedDiet and based on the Self-Determination Theory (SDT) on dietary intakes, eating behaviors, anthropometric and metabolic variables, in men and women presenting cardiovascular risk factors.MethodsSixty-four men and 59 premenopausal women were recruited. The 12-week nutritional program used a motivational interviewing approach and included individual and group sessions. A food frequency questionnaire was administered to evaluate dietary intakes from which a Mediterranean score (Medscore) was derived and the Three-Factor Eating Questionnaire allowed assessment of eating behaviors. Measurements were performed at baseline and after the 12-week nutritional intervention, and then at 3 and 6-month post intervention.ResultsNo gender difference was observed in changes in the Medscore during the nutritional intervention and follow-up. However, the Medscore returned towards baseline values during follow-up in men and women (P <0.0001). Men reported larger decreases in red and processed meat and larger increases in whole fruit intakes than women (P = 0.03 and P = 0.04, respectively). Men showed a greater decrease in habitual susceptibility to disinhibition than women (P = 0.03). A gender by time interaction was found for waist circumference, i.e. men had lower waist circumference at the end of the intervention as well as at follow-up than at baseline while women’s waist circumference decreased in response to the intervention only (P = 0.05). As for metabolic variables, changes observed in total-cholesterol (C) to HDL-C ratio, triglyceride levels and triglycerides to HDL-C ratio were more pronounced in men than in women after the intervention as well as at follow-up (P ≤0.03).ConclusionsOur results indicate that the 12-week nutritional intervention based on the SDT leads to more pronounced beneficial changes in long-term dietary intakes in men than in women and to greater improvements in metabolic profile in men.Trial registrationCurrent Controlled Trials NCT01852721.

Influences of apolipoprotein E polymorphism on the response of plasma lipids to the Ad libitum consumption of a high-carbohydrate diet compared with a high-monounsaturated fatty acid diet

The purpose of this study was to assess the contribution of the apolipoprotein E (apoE) polymorphism and factors, such as age and waist circumference, to variations in plasma low-density lipoprotein-cholesterol (LDL-C) response following ad libitum consumption of a diet rich in complex carbohydrates (high-CHO: 58% of energy as CHO) versus a diet rich in fat and monounsaturated fatty acids (high-MUFA: fat, 40% of energy and 22% as MUFA). Sixty-five men participated in this parallel 6- to 7-week study involving either a high-CHO or a high-MUFA diet. Fasting plasma lipid profile and anthropometry were determined at the beginning and at the end of the dietary period. The high-CHO and high-MUFA diets both induced significant (P<.01) and comparable reductions in body weight and waist circumference. These changes were associated with a significant (P<.01) and comparable decrease in LDL-C (-19% and -16%, respectively). Stepwise multiple regression analyses showed that 32% of the variation in the LDL-C response to the high-CHO diet was attributable to the apoE polymorphism (18.5%, P=.04) and waist circumference (13.5%, P=.03) indicating that men with a waist circumference greater than 100 cm and the E2 allele had the greatest reduction in plasma LDL-C after the high-CHO diet. On the other hand, in the high-MUFA group, waist circumference was the only significant contributing factor to the LDL-C response and accounted for 44.5% of its variance. In conclusion, the plasma LDL-C response to ad libitum comsumption of a high-CHO and a high-MUFA diets are not modulated to the same extent by the apoE polymorphism and waist circumference.

The Contribution of Visceral Adiposity and Mid-Thigh Fat-Rich Muscle to the Metabolic Profile in Postmenopausal Women

This study explored the relationship between muscle fat infiltration derived from mid‐thigh computed tomography (CT) scan, central fat distribution and insulin sensitivity in postmenopausal women. Mid‐thigh CT scans were used to measure low attenuation muscle surface (LAMS) (0–34 Hounsfield units (HU)), which represented a specific component of fat‐rich muscle. Whole‐body insulin sensitivity (M/I) was evaluated by an euglycemic‐hyperinsulinemic clamp. A group of 103 women aged 57.0 ± 4.4 years was studied. Women with higher levels of LAMS presented higher metabolic risk features, particularly elevated fasting, 2‐h plasma glucose (2hPG) concentrations and diminished M/I (P < 0.05). To further study the contribution of muscle fat infiltration and central adiposity on metabolic parameters, we divided the whole group based on the median of LAMS and visceral adipose tissue (VAT). As expected, the best metabolic profile was found in the Low‐LAMS/Low‐VAT group and the worst in the High‐LAMS/High‐VAT group. Women with Low‐LAMS/High‐VAT presented similar metabolic risks to those with High‐LAMS/High‐VAT. There was no difference between High‐LAMS/Low‐VAT and Low‐LAMS/Low‐VAT, which presents the most healthy metabolic and glycemic profiles as reflected by the lowest levels of cardiovascular disease risk variables. This suggests that High‐LAMS/Low‐VAT is also at low risk of metabolic deteriorations and that High‐LAMS, only in the presence of High‐VAT seems associated with deteriorated risks. Although increased mid‐thigh fat‐rich muscle was related to a deteriorated metabolic profile, VAT appears as a more important contributor to alterations in the metabolic profile in postmenopausal women.

The WHO and NCEP/ATPIII Definitions of the Metabolic Syndrome in Postmenopausal Women: Are They So Different?

BACKGROUND The aim of this study was to examine the metabolic risk profile in postmenopausal women characterized by either the metabolic syndrome (MS) as defined by the World Health Organization (WHO) or the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATPIII). METHODS One hundred and eight postmenopausal women (56.9 +/- 4.2 years; 28.5 +/- 5.9 kg/m(2)) were examined. Each underwent an oral glucose tolerance test, an euglycemic-hyperinsulinemic clamp, an assessment of body fat distribution by computed tomography, a complete plasma lipid-lipoprotein profile, and standard measurements of inflammatory markers. RESULTS The prevalence of the MS-WHO was 29.6% in our women. Type 2 diabetes was found in 28.1% of women with the MS-WHO. Thirty-one percent of women had the MS-ATP, from which 36.4% had type 2 diabetes. Among the 32 women identified as having MS-WHO, 25 (78.1 %) were also identified as having the MS-ATP. On the other hand, among the 34 women identified as having MS-ATP, 24 (70.0 %) also had MS-WHO (kappa = 0.60). When we subdivided our sample of women as having either isolated MS-WHO, isolated MS-ATP, or combined MS-WHO and MS-ATP, we observed a more deteriorated metabolic risk profile (higher values for visceral adipose tissue, 2-h plasma glucose, and lower HDL-cholesterol concentrations) in women characterized by isolated MS-ATP compared to women with isolated MS-WHO. CONCLUSIONS These results suggest that, in postmenopausal women, the concordance in the identification of subjects with the MS using each of the proposed definitions is only moderate.