Persons Successful at Long-term Weight Loss and Maintenance Continue to Consume a Low-energy, Low-fat Diet

Objectives To describe the dietary intakes of persons who successfully maintained weight loss and to determine if differences exist between those who lost weight on their own vs those who received assistance with weight loss (eg, participated in a commercial or self-help program or were seen individually by a dietitian). Intakes of selected nutrients were also compared with data from the third National Health and Nutrition Examination Survey (NHANES III) and the 1989 Recommended Dietary Allowances (RDAs).Subjects Subjects were 355 women and 83 men, aged 18 years or older, primarily white, who had maintained a weight loss of at least 13.6 kg for at least 1 year, and were the initial enrollees in the ongoing National Weight Control Registry. On average, the participants had lost 30 kg and maintained the weight loss for 5.1 years.Methods A cross-sectional study in which subjects in the registry completed demographic and weight history questionnaires as well as the Health Habits and History Questionnaire developed by Block et al. Subjects’ dietary intake data were compared with that of similarly aged men and women in the NHANES III cohort and to the RDAs. Adequacy of the diet was assessed by comparing the intake of selected nutrients (iron; calcium; and vitamins C, A, and E) in subjects who lost weight on their own or with assistance.Results Successful maintainers of weight loss reported continued consumption of a low-energy and low-fat diet. Women in the registry reported eating an average of 1,306 kcal/day (24.3% of energy from fat); men reported consuming 1,685 kcal (23.5% of energy from fat). Subjects in the registry reported consuming less energy and a lower percentage of energy from fat than NHANES III subjects did. Subjects who lost weight on their own did not differ from those who lost weight with assistance in regards to energy intake, percent of energy from fat, or intake of selected nutrients (iron; calcium; and vitamins C, A, and E). In addition, subjects who lost weight on their own and those who lost weight with assistance met the RDAs for calcium and vitamins C, A, and E for persons aged 25 years or older.Applications Because continued consumption of a low-fat, low-energy diet may be necessary for long-term weight control, persons who have successfully lost weight should be encouraged to maintain such a diet. J Am Diet Assoc. 1998;98:408–413.     

A Low-Fat Intake and Greater Activity Level are Associated With Lower Weight Regain 3 Years After Completing a Very–Low-Calorie Diet

Objective To examine the roles of diet, exercise, and lifestyle factors in determining long-term weight regain after weight loss with a very–low-calorie diet (VLCD).Subjects Twenty-seven of 38 women who lost weight with a VLCD.Design Graduates of a weight loss intervention study returned for follow-up 3 years after program completion. Percentage of initial weight loss that was regained was correlated with subjects’ fat intake (assessed via 7-day food records and a Diet Habit Survey), energy intake (assessed via 7-day food records), activity level and lifestyle factors (assessed via questionnaires) that are supportive of weight loss maintenance.Statistical analyses performed Regression analysis was used to assess the relationship of weight regain with fat intake, activity level, and energy intake. Contingency table analysis was used to assess the association between weight regain and lifestyle factors.Results Subjects followed experienced a −20.7 kg±9.2 kg (−19.2%±7%) (mean±standard deviation) weight change during the original VLCD program and a 13.9 kg±11.3 kg (76.6%±52.1%) weight change 3 years post-VLCD. Fat intake, assessed by a 7-day food diary, was positively correlated with weight regain at 3 years (r=0.66, P=.0004). Less weight regain was also seen with a lower percent fat intake as reflected by a higher Diet Habit Survey score (r=−0.55, P=.004). Women with the lowest tertile of reported fat intake (<25% of energy) from the Diet Habit Survey regained the least amount of weight (P=.05). Activity level was negatively correlated with weight regain (r=−0.53, P=.005). After correction for multiple comparisons, there was no association between total energy intake and weight regain. Lifestyle factors were also not associated with weight regain.Applications/conclusions Identifying strategies to maintain weight loss is crucial because of the negative health effects and increasing prevalence of obesity. For women who have lost weight on a VLCD, limiting dietary fat intake and maintaining physical activity are both important factors for the prevention of weight regain. To promote better weight loss outcomes, registered dietitians should help clients who have lost weight limit their fat intake to less than 30% of energy and encourage high activity levels. J Am Diet Assoc. 2002;102:1252–1256.     

A Low-Fat Diet Supplemented With Monounsaturated Fat Results in Less HDL-C Lowering Than a Very-Low-Fat Diet

Objective The purpose of this study was to compare the effects of a very-low-fat diet with a low-fat diet supplemented with monounsaturated oil on plasma lipid levels in subjects with hypercholesterolemia.Design The 8-week study was divided into one 2-week baseline diet and two 3-week intervention periods in a randomized crossover design.Setting The study was conducted in an outpatient setting at the Deakin Institute of Human Nutrition, Deakin University, Geelong, Australia.Subjects Twenty-four free-living subjects with hypercholesterolemia participated in and completed the study.Intervention After a 2-week baseline period of a self-selected diet, subjects were assigned to one of two dietary interventions: a very-low-fat (10% of energy from fat), high-carbohydrate diet or a low-fat (26% of energy from fat) diet supplemented with olive oil and an olive oil-based margarine.Main outcome measures Lipid measurements included total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride concentrations. Plasma cholesteryl esters were measured to monitor compliance.Statistical analyses A paired t test was used to assess differences between treatment periods for each subject. The dependence of the difference between treatment periods on the covariates of age, sex, initial cholesterol concentration, and energy intake was analyzed using repeated measures and analysis of covariance.Results The low-fat diet supplemented with monounsaturated fat resulted in significantly less high-density lipoprotein cholesterol lowering than the very-low-fat diet (P=.005). Both interventions resulted in significant reductions in both low-density lipoprotein cholesterol and total cholesterol compared with the baseline diet.Applications This study suggests that a low-fat diet enriched with olive oil provides advantages over a very-low-fat diet in the control of serum lipoproteins among persons with hypercholesterolemia. J Am Diet Assoc. 1997; 97:151–156.     

Sensory Responses to Fat are Not Affected by Varying Dietary Energy Intake From Fat and Saturated Fat Over Ranges Common in the American Diet

Objective To examine the effects of manipulating dietary fat in foods on sensitivity and hedonic response to fat in selected foods.Design Twenty subjects were randomly assigned to a sequence of three 8-week experimental diets (average American diet, step 1 diet, low-saturated-fat diet) that varied in energy from fat (37%, 30%, and 26%, respectively) and saturated fat (17%, 10%, and 6%, respectively). Subjects participated in sensory tests designed to assess their sensitivity to and liking for fat in several foods, before the study (baseline), after consumption of each diet, and after the study (washout).Subjects/setting Subjects were participants in the Dietary Effects on Lipoprotein and Thrombogenic Activity (DELTA) study.Results No significant differences were found among diets for difference thresholds (ie, just noticeable differences) for fat in milk and pudding, ad libitum mixing of low- and high-fat samples of milk and soup, and hedonic scaling of fat concentrations in milk and muffins and of cheese, mayonnaise, hot dog, and pastry samples.Applications/conclusions Within the dietary fat ranges and for the fat stimuli tested in this study, dietary fat as percentage of energy from fat and saturated fat was not a significant determinant of sensitivity to and/or liking for fat. Sensory factors should not be a barrier to the implementation of low-fat diets such as the step 1 and low-saturated-fat diets. J Am Diet Assoc. 1999;99:690–696.     

Lower Fat Intake as a Predictor of Initial and Sustained Weight Loss in Obese Subjects Consuming an Otherwise ad Libitum Diet

Objective To determine what predicts initial and sustained weight loss in subjects consuming a reduced-fat diet ad libitum and the relationship between achieved level of fat intake and weight loss.Design Placebo arm of a randomized, controlled trial of a weight-loss drug (dexfenfluramine) in the context of an ad libitum, reduced-fat, diet.Subjects Thirty-nine subjects (initial mean body mass index±standard deviation=34.9±3.4; body mass index is calculated as kg/m²) from the placebo group who completed the 9-month study.Intervention Dietary assessment and education (month 0) followed by monthly meetings during the single intervention of reducing fat intake (months 1 through 6); one follow-up at 9 months.Main outcome measures Initial weight loss (first 3 months) and sustained weight loss (over 9-month period).Statistics Dietary intake, body size, exercise levels, age, and gender were included in multiple regression linear models of initial and sustained weight loss if they were significant independent predictors.Results Greater initial weight loss was associated with a greater decrease in fat intake and a lower achieved fat intake at 3 months. Greater sustained weight loss was associated with a lower achieved fat intake, a higher baseline waist circumference, and higher moderate-intensity exercise levels (months 3 and 6). Weight loss occurred in all subjects who reported a fat intake of 40 g/day or less.Applications The obese persons most likely to achieve and sustain weight loss on an ad libitum, reduced-fat diet are those who can substantially reduce fat intake, those with high initial levels of abdominal fat, and those who undertake regular moderate-intensity exercise. A target of less than 40 g fat per day might be an appropriate goal to ensure weight loss, but dietary underreporting and the difficulty of sustaining very-low-fat intakes need to be considered. J Am Diet Assoc. 1998;98:35-39.     

Increased consumption of dairy foods and protein during diet- and exercise-induced weight loss promotes fat mass loss and lean mass gain in overweight and obese premenopausal women

Weight loss can have substantial health benefits for overweight or obese persons; however, the ratio of fat:lean tissue loss may be more important. We aimed to determine how daily exercise (resistance and/or aerobic) and a hypoenergetic diet varying in protein and calcium content from dairy foods would affect the composition of weight lost in otherwise healthy, premenopausal, overweight, and obese women. Ninety participants were randomized to 3 groups (n = 30/group): high protein, high dairy (HPHD), adequate protein, medium dairy (APMD), and adequate protein, low dairy (APLD) differing in the quantity of total dietary protein and dairy food-source protein consumed: 30 and 15%, 15 and 7.5%, or 15 and <2% of energy, respectively. Body composition was measured by DXA at 0, 8, and 16 wk and MRI (n = 39) to assess visceral adipose tissue (VAT) volume at 0 and 16 wk. All groups lost body weight (P < 0.05) and fat (P < 0.01); however, fat loss during wk 8-16 was greater in the HPHD group than in the APMD and APLD groups (P < 0.05). The HPHD group gained lean tissue with a greater increase during 8-16 wk than the APMD group, which maintained lean mass and the APLD group, which lost lean mass (P < 0.05). The HPHD group also lost more VAT as assessed by MRI (P < 0.05) and trunk fat as assessed by DXA (P < 0.005) than the APLD group. The reduction in VAT in all groups was correlated with intakes of calcium (r = 0.40; P < 0.05) and protein (r = 0.32; P < 0.05). Therefore, diet- and exercise-induced weight loss with higher protein and increased dairy product intakes promotes more favorable body composition changes in women characterized by greater total and visceral fat loss and lean mass gain.     

Snack Selection Influences Nutrient Intake, Triglycerides, and Bowel Habits of Adult Women: A Pilot Study

Because appropriate snacking can promote a healthy body weight and serve as an important contributor to a healthy diet for women, identification of suitable foods for incorporation between meals is essential. We investigated the influence of short-term (2 weeks) incorporation of 100-kcal servings of snacks of dried plums vs low-fat cookies twice daily on total energy and nutrient intake, biochemical parameters, and bowel habits in a randomized crossover design of two 2-week trials separated by a 2-week wash-out period in 26 women aged 25 to 54 years with a body mass index between 24 and 35. Incorporation of dried plums or low-fat cookies into the diet did not alter energy intake or weight; however, compared to cookies, dried plums promoted greater (P≤0.05) intake of fiber, potassium, riboflavin, niacin, and calcium. Total fat intake tended (P=0.094) to decrease with dried plum consumption, as did cholesterol intake (P=0.098). Plasma triglyceride concentration remained unchanged (P>0.05) by dried plum consumption and was 17.0±29.2 mg/dL (0.19±0.33 mmol/L) higher (P≤0.05) after consumption of low-fat cookies vs dried plums at the end of 2 weeks. Dried plums promoted a softer (P≤0.05) stool consistency vs usual intake and in comparison to intake of low-fat cookies. These results suggest that relative to a commercially processed low-fat cookie snack, dried plums promote more favorable plasma triglyceride responses, improved dietary quality, and slightly improved bowel function.     

Body composition of patients with Alzheimer's disease

Low body weight is frequently reported in patients with Alzheimer's disease. We sought to discover why by comparing the body composition of 28 cognitively normal elders and 23 institutionalized individuals with Alzheimer's disease. Body mass index was calculated from standing height and weight. Percentages of lean body mass, body fat, and body water were derived from bioimpedance measurements of resistance and reactance. Skinfold thickness was measured at seven body sites to estimate regional fat distribution. Variables were analyzed by analysis of variance with subjects grouped by cognitive status within gender. Activity level and age were not significant covariates. Both women and men with Alzheimer's disease weighed less than control subjects. Differences in body composition were more pronounced in women with Alzheimer's disease, who had lower body mass index (22.0 ± 3.0 vs 26.1 ± 5.1), higher percentage of lean body mass (73.8 ± 5.1 vs 66.9 ± 6.5), lower percentage of body fat (26.1 ± 5.1 vs 33.1 ± 6.5), and higher percentage of body water (55.8 ± 5.0 vs 49.3 ± 6.5) compared with control women. Except for lower body weight, the body composition of men with Alzheimer's disease was not significantly different from that of control men. Patients of both sexes with Alzheimer's disease had less truncal body fat compared with controls, which gave them a youthful body habitus. These differences were not accounted for by age, diet, or activity. Our findings indicate that patients with Alzheimer's disease have lower body weight and may require higher energy intake than cognitively normal elders.     

Efficacy of orlistat 60 mg on weight loss and body fat mass in US Army soldiers

A higher body mass index is associated with exercise-related injuries and increased risk for musculoskeletal and connective tissue disorders, which are relevant to military personnel. Studies show the efficacy of orlistat 60 mg for promoting weight and body fat loss in civilians; however, its efficacy among predominantly young, male soldiers is unknown. This study's objective was to examine the effect of a 6-month, standard education-based weight-management program with and without orlistat 60 mg on changes in weight and body fat in overweight soldiers. Data were collected for this randomized, controlled trial from March 2008 to November 2010 at Fort Bragg, NC. Participants were enrolled in an education-based weight management program (n=435; 75% men) and were randomized to placebo or orlistat 60 mg, three capsules daily with meals. All participants were recommended to maintain a reduced-energy, low-fat diet. Among study completers (14% retention rate; placebo n=22, orlistat n=35) members of both groups lost significant weight from baseline (placebo ?3.0±5.2 kg; orlistat ?3.2±4.7 kg; P<0.01), but only the orlistat group lost fat mass (?2.5±3.9 kg; P<0.001), whereas the placebo group lost lean mass (?1.4±2.7 kg; P <0.01). An intent-to-treat analysis (≥1 follow-up body weight measure) demonstrated that the orlistat group lost more fat mass vs the placebo group (?1.3±2.9 kg vs ?0.6±1.8 kg, respectively; P<0.05), but less lean mass (?0.2±2.0 kg vs ?0.8±1.8 kg, respectively; P<0.01). Orlistat 60 mg may be an effective adjunct to an education-based weight management program in a mostly young, male soldier population.     

Dietary protein and exercise have additive effects on body composition during weight loss in adult women

This study examined the interaction of 2 diets (high protein, reduced carbohydrates vs. low protein, high carbohydrates) with exercise on body composition and blood lipids in women (n = 48, approximately 46 y old, BMI = 33 kg/m(2)) during weight loss. The study was a 4-mo weight loss trial using a 2 x 2 block design (Diet x Exercise). Diets were equal in total energy (7.1 MJ/d) and lipids ( approximately 30% energy intake) but differed in protein content and the ratio of carbohydrate:protein at 1.6 g/(kg . d) and <1.5 (PRO group) vs. 0.8 g/(kg . d) and >3.5 (CHO group), respectively. Exercise comparisons were lifestyle activity (control) vs. a supervised exercise program (EX: 5 d/wk walking and 2 d/wk resistance training). Subjects in the PRO and PRO + EX groups lost more total weight and fat mass and tended to lose less lean mass (P = 0.10) than the CHO and CHO + EX groups. Exercise increased loss of body fat and preserved lean mass. The combined effects of diet and exercise were additive for improving body composition. Serum lipid profiles improved in all groups, but changes varied among diet treatments. Subjects in the CHO groups had larger reductions in total cholesterol and LDL cholesterol, whereas subjects in the PRO groups had greater reductions in triacylglycerol and maintained higher concentrations of HDL cholesterol. This study demonstrated that a diet with higher protein and reduced carbohydrates combined with exercise additively improved body composition during weight loss, whereas the effects on blood lipids differed between diet treatments.     

Effects of a low-fat diet compared with those of a high-monounsaturated fat diet on body weight, plasma lipids and lipoproteins, and glycemic control in type 2 diabetes

BACKGROUND: An important therapeutic goal for patients with type 2 diabetes is weight loss, which improves metabolic abnormalities. Ad libitum low-fat diets cause weight loss in nondiabetic populations. Compared with diets higher in monounsaturated fat, however, eucaloric low-fat diets may increase plasma triacylglycerol concentrations and worsen glycemic control in persons with type 2 diabetes. OBJECTIVE: We investigated whether, in type 2 diabetes patients, an ad libitum low-fat diet would cause greater weight loss than would a high-monounsaturated fat diet and would do this without increasing plasma triacylglycerol concentrations or worsening glycemic control. DESIGN: Eleven patients with type 2 diabetes were randomly assigned to receive an ad libitum low-fat, high-carbohydrate diet or a high-monounsaturated fat diet, each for 6 wk. The diets offered contained 125% of the estimated energy requirement to allow self-selection of food quantity. The response variables were body weight; fasting plasma lipid, lipoprotein, glucose, glycated hemoglobin A(1c), and fructosamine concentrations; insulin sensitivity; and glucose disposal. RESULTS: Body weight decreased significantly (1.53 kg; P < 0.001) only with the low-fat diet. Plasma total, LDL-, and HDL-cholesterol concentrations tended to decrease during both diets. There were no interaction effects between diet and the lipid profile response over time. Plasma triacylglycerol concentrations, glycemic control, and insulin sensitivity did not differ significantly between the 2 diets. CONCLUSION: Contrary to expectations, the ad libitum, low-fat, high-fiber diet promoted weight loss in patients with type 2 diabetes without causing unfavorable alterations in plasma lipids or glycemic control.     

The role of dietary fat in body fatness: evidence from a preliminary meta-analysis of ad libitum low-fat dietary intervention studies

The role of high-fat diets in weight gain and obesity has been questioned because of inconsistent reports in the literature concerning the efficacy of ad libitum low-fat diets to reduce body weight. We conducted a meta-analysis of weight loss occurring on ad libitum low-fat diets in intervention trials, and analysed the relationship between initial body weight and weight loss. We selected controlled trials lasting more than 2 months comparing ad libitum low-fat diets with a control group consuming their habitual diet or a medium-fat diet ad libitum published from 1966 to 1998. Data were included from 16 trials with a duration of 2-12 months, involving 1728 individuals. No trials on obese subjects fulfilled the inclusion criteria. The weighted difference in weight loss between intervention and control groups was 2.55 kg (95% CI, 1.5-3.5; P < 0.0001). Weight loss was positively and independently related to pre-treatment body weight (r = 0.52, P < 0.05) and to reduction in the percentage of energy as fat (0.37 kg/%, P < 0.005) in unweighted analysis. Extrapolated to a BMI of about 30 kg/m2 and assuming a 10% reduction in dietary fat, the predicted weight loss would be 4.4 kg (95% CI, 2.0 to -6.8 kg). Because weight loss was not the primary aim in 12 of the 16 studies, it is unlikely that voluntary energy restriction contributed to the weight loss. Although there is no evidence that a high intake of simple sugars contributes to passive overconsumption, carbohydrate foods with a low glycaemic index may be more satiating and exert more beneficial effects on insulin resistance and cardiovascular risk factors. Moreover, an increase in protein content up to 25% of total energy may also contribute to reducing total energy intake. In conclusion, a low-fat diet, high in protein and fibre-rich carbohydrates, mainly from different vegetables, fruits and whole grains, is highly satiating for fewer calories than fatty foods. This diet composition provides good sources of vitamins, minerals, trace elements and fibre, and may have the most beneficial effect on blood lipids and blood-pressure levels. A reduction in dietary fat without restriction of total energy intake prevents weight gain in subjects of normal weight and produces a weight loss in overweight subjects, which is highly relevant for public health.     

Low-fat diets and energy balance: how does the evidence stand in 2002?

The role of high-fat diets in weight gain and obesity is assessed by evidence-based principles. Four meta-analyses of weight change occurring on ad libitum low-fat diets in intervention trials consistently demonstrate a highly significant weight loss of 3-4 kg in normal-weight and overweight subjects (P < 0.001). The analyses also find a dose-response relationship, i.e. the reduction in percentage energy as fat is positively associated with weight loss. Weight loss is also positively related to initial weight; a 10 % reduction in dietary fat is predicted to produce a 4-5 kg weight loss in an individual with a BMI of 30 kg/m2. The non-fat macronutrient composition of the diet is also important. Whereas the glycaemic index of the carbohydrate may play a role for cardiovascular risk factors, there is so far no evidence that low-glycaemic index foods facilitate weight control. In contrast, intervention studies show that sugar in drinks is more likely to produce weight gain than solid sugar in foods. Although the evidence is weak, alcoholic beverages promote a positive energy balance, and wine may be more obesity-promoting than beer. Protein is more satiating and thermogenic than carbohydrates, and one intervention study has shown that an ad libitum low-fat diet where carbohydrate was replaced by protein produced more weight loss after 6 months (8.1 v. 5.9 kg). The evidence linking particular fatty acids to body fatness is weak. If anything, monounsaturated fat may be more fattening than polyunsaturated and saturated fats, and no ad libitum dietary intervention study has shown that a normal-fat high-monounsaturated fatty acid diet is equivalent or superior to a low-fat diet in the prevention of weight gain and obesity. The evidence strongly supports the low-fat diet as the optimal choice for the prevention of weight gain and obesity, while the use of a normal-fat high-monounsaturated fatty acid diet is unsubstantiated.     

A highly saturated fat-rich diet is more obesogenic than diets with lower saturated fat content

The present study tested the hypothesis that a saturated fatty acid (SFA)–rich diet is more obesogenic than diets with lower SFA content. In 8 female Sprague-Dawley rats fed a low-SFA canola or a moderate-SFA lard-rich diets at 67% of energy for 26 days, body weight gain, final body weight, obesity index, and food and energy intake were comparable. Twenty-nine rats were fed canola or high-SFA butter-rich diets (67% of energy) or chow for 50 days; then high-fat feeding was followed by ad libitum low-fat feeding (27% of energy) for 28 days and by a food-restricted low-fat diet for 32 days. High-fat feeding resulted in a greater body weight gain (P < .04), final body weight (P < .04), and energy intake (P < .008) in butter-fed rats than in canola- and chow-fed controls, after 26 or 50 days. Ad libitum canola and butter low-fat diets or chow feeding resulted in similar weight change, whereas food-restricted low-fat diets led to comparable weight loss and final weight. Canola-fed animals adjusted their intake based on diet energy density, whereas lard and butter-fed animals failed to do so. Abdominal fat (P = .012) and plasma leptin (P = .005) were higher in chow-fed controls than in canola-fed rats, but comparable with those of butter-fed rats. Prone and resistant phenotypes were detected with high-fat feeding. In conclusion, only feeding the high-SFA butter-rich diet led to obesity development and failure to adjust intake based on the energy density and preserving body fat even after weight loss. The high availability of SFA-rich foods in today's obesogenic environment could contribute to develop and maintain obesity.     

Prognostic value of changes in lean and fat mass in alcoholics

Background & aims

The prognostic value of nutritional status and/or lean and fat mass assessed by dual-energy X-ray absorptiometry (DEXA) has been widely analyzed, in both alcoholics and non-alcoholics. However, the prognostic value of changes in fat and lean mass over time in alcoholics has scarcely been studied, nor has the effect of alcohol abstinence on these changes.

Methods

From an initial cohort of 113 alcoholic patients, 70 prospectively underwent two DEXA assessments six months apart. One hundred and five patients (including 66 of those who underwent two DEXA assessments) were followed up for 34.9 ± 36.4 months (median = 18 months, interquartile range = 7.25–53.75 months). During this follow-up period, 33 died (including 20 of those who had undergone a second DEXA assessment).

Results

Forty-two of the 70 patients undergoing a second DEXA assessment had abstained from alcohol. Of these, 69.04% (29) gained left arm lean mass, compared with only 35.71% (10 of 28) of those who had continued drinking (χ² = 7.46; p = 0.006). Similar results were observed regarding right arm lean mass (χ² = 4.68; p = 0.03) and right leg lean mass (χ² = 7.88; p = 0.005). However, no associations were found between alcohol abstinence and changes in fat parameters. Analysis by means of Kaplan–Meier curves showed that loss of total lean mass, right leg lean mass, left leg lean mass and total fat mass were all significantly associated with reduced survival. However, within 30 months of the second evaluation, significant associations were observed between changes of all parameters related to lean mass, and mortality, but no association between changes in fat parameters and mortality.

Conclusions

Loss of lean mass over a period of six months after a first assessment is associated with worse prognosis in alcoholics, irrespective of whether they stop drinking during this period or not. Continued drinking is associated with greater loss of lean mass, but not with changes in fat mass.     

Plasma C-reactive protein concentration is not affected by isocaloric dietary fat reduction

OBJECTIVE: There is a strong correlation between plasma C-reactive protein (CRP) concentration and risk of cardiovascular death. Low-fat diets have been recommended for maintenance of cardiovascular health, and it is known that a low-fat diet associated with weight loss lowers CRP concentration. However, it remains unclear whether dietary fat has an effect independent from weight change on markers of inflammation. METHODS: Sixteen overweight subjects who were 46 +/- 14 y old were placed on a weight-maintaining baseline diet consisting of 35% fat, 45% carbohydrate, and 20% energy as protein. After 2 wk, subjects were switched to an isocaloric low-fat diet consisting of 15% fat, 65% carbohydrate, and 20% protein for another 2 wk. For the final 12 wk of the study, subjects consumed the same 15% fat diet ad libitum. At the end of each diet phase, CRP was measured by a high-sensitivity CRP assay. RESULTS: The weight of subjects remained stable during the first 4 wk of isocaloric diets. Plasma CRP concentrations after 2 wk on the weight-maintaining 35% fat diet and 2 wk on the isocaloric 15% fat diet were not significantly different (median +/- interquartile range 1.42 +/- 3.30 and 1.59 +/- 3.29 mg/L, respectively). Three months of ad libitum low-fat diet consumption resulted in a 4.1 +/- 0.7 kg weight loss associated with a decrease in CRP concentration to 1.17 +/- 2.03 mg/L (P = 0.03). CONCLUSION: Loss of body weight decreases CRP concentration, but a decrease in dietary fat without a concurrent change in body weight does not affect CRP concentration in overweight healthy subjects.     

Very low-fat (12%) and high monounsaturated fat (35%) diets do not differentially affect abdominal fat loss in overweight, nondiabetic women

Studies in women with type 2 diabetes demonstrated adverse effects on body fat distribution of a low-fat diet relative to a high monounsaturated fat diet. We performed a randomized 12-wk parallel design study of two 6000-kJ diets: 35% energy from fat (high monounsaturated fat diet, HIMO), or 12% energy from fat (very low-fat diet, VLF) to determine whether this also occurred in nondiabetic women. Body fat distribution, fasting plasma glucose, blood pressure, and fasting serum lipids were measured at wk 0 and 12 in 62 women (BMI > 27 kg/m(2)). Weight loss (9.5 +/- 2.4 vs. 9.4 +/- 3.4 kg, VLF vs. HIMO) and total fat loss (6.1 +/- 2.4 vs. 6.3 +/- 2.7 kg, VLF vs. HIMO) did not differ in the groups. There was a diet x menopausal status interaction in lean mass changes (P = 0.005) such that in premenopausal women, HIMO produced a lower loss of lean mass than the low-fat diet (0.4 +/- 2.3 vs. 2.9 +/- 2.7 kg, P = 0.006) with the opposite but nonsignificant effect seen in postmenopausal women. There was a greater decrease in total plasma cholesterol in women who consumed VLF compared with those who consumed HIMO (0.82 +/- 0.0.51 vs. 0.50 +/- 0.48 mmol/L, P < 0.001 for time, P < 0.05 for diet effect). This was also true for the change in HDL cholesterol (0.18 +/- 0.23 vs. 0.04 +/- 0.19 mmol/L, VLF and HIMO, respectively, P < 0.001 for time, P < 0.05 for diet effect). The LDL/HDL ratio was reduced in both groups with no effect of diet (0.16 +/- 0.51 vs. 0.16 +/- 0.45, VLF and HIMO, respectively, P < 0.05). In conclusion, weight, total fat mass, and regional fat mass loss did not differ in the 2 groups of women but there was an apparent preservation of lean mass in premenopausal women consuming HIMO.     

Reduced neural responses to food cues might contribute to the anorexigenic effect of acute exercise observed in obese but not lean adolescents

Acute exercise has been found to reduce subsequent energy intake in obese adolescents. Although it has been suggested that some neural pathways are involved in this post-exercise energy intake regulation, it remains unknown whether the post-exercise attentional response to food cues differs as a function of weight status. We hypothesize that there will be a reduction in the neural response to food cues as a result of exercise in obese adolescents, but not in their lean counterparts. Fourteen obese and 14 lean adolescent boys (12-15 years) were randomized (within-subjects design) to remain seated (CON) or to exercise 45 minutes at 65% of their maximal capacities (EX). After the exercise or sitting period, the adolescents' cognitive engagement in the processing of food vs. non-food cues was assessed during an attentional computer-based task with electroencephalography (EEG) recording. An ad libitum lunch meal was offered and appetite feelings were assessed (visual analog scales). There was no main effect of condition on energy intake in lean subjects, but obese adolescents ate significantly less following EX compared with CON (P < .05). There was no effect of condition or stimulus type (food vs. non-food) on the EEG-recorded amplitude of the P3b component in lean adolescents. However, the response to food cues was significantly reduced compared with non-food stimuli after exercise in obese participants (P < .01). Following EX, but not CON, total body weight, body mass index, and fat mass were inversely correlated with the EEG response to food–non-food stimuli (all P < .05). However, this response was not associated with ad libitum EI (both P > .1). Acute exercise favors decreased neural response to food cues compared with non-food cues in obese but not lean adolescents, suggesting differential effects of exercise on the neural processing of food cues based on weight status.