Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8-week equi-energetic energy-restricted diet.

There have been reports of an inverse relationship between meal frequency (MF) and adiposity. It has been postulated that this may be explained by favourable effects of increased MF on appetite control and possibly on gut peptides as well. The main goal of the present study was to investigate whether using a high MF could lead to a greater weight loss than that obtained with a low MF under conditions of similar energy restriction. Subjects were randomised into two treatment arms (high MF = 3 meals+3 snacks/d or low MF = 3 meals/d) and subjected to the same dietary energy restriction of - 2931 kJ/d for 8 weeks. Sixteen obese adults (n 8 women and 8 men; age 34.6 (sd 9.5); BMI 37.1 (sd 4.5) kg/m2) completed the study. Overall, there was a 4.7 % decrease in body weight (P < 0.01); similarly, significant decreases were noted in fat mass ( - 3.1 (sd 2.9) kg; P < 0.01), lean body mass ( - 2.0 (sd 3.1) kg; P < 0.05) and BMI ( - 1.7 (sd 0.8) kg/m2; P < 0.01). However, there were NS differences between the low- and high-MF groups for adiposity indices, appetite measurements or gut peptides (peptide YY and ghrelin) either before or after the intervention. We conclude that increasing MF does not promote greater body weight loss under the conditions described in the present study.

Physical activity is a confounding factor of the relation between eating frequency and body composition.

BACKGROUND: It has been shown that eating frequency (EF) is related to body composition in women, but the results are inconclusive. These inconsistent findings could be due to the influence of additional factors such as physical activity. OBJECTIVE: We aimed to investigate the relation between EF and body composition in premenopausal women and to explore the effect of physical activity energy expenditure (PAEE) and physical fitness on that association. DESIGN: Eighty-five premenopausal women [x +/- SD age: 49.9 +/- 2.0 y; body mass index (in kg/m(2)): 23.2 +/- 2.2] were studied at the onset of a prospective observational study. Seven-day food diaries were used to measure energy intake and EF. Body composition (measured with dual-energy X-ray absorptiometry), physical fitness (measured by the peak oxygen consumption), and PAEE (measured by using an accelerometer) were also measured. RESULTS: Mean EF was 4.6 +/- 0.9 eating occasions/d. A significant positive correlation was found between EF and energy intake (r = 0.31, P < 0.01). Moreover, EF was negatively correlated with body mass index (r = -0.25, P < 0.05), waist circumference (r = -0.32, P < 0.01), percentage body fat (r = -0.26, P < 0.05), and fat mass (r = -0.27, P < 0.05). The associations between adiposity and EF were no longer significant after correction for PAEE and peak oxygen consumption. CONCLUSION: The relation between EF and body composition could be mediated by PAEE and physical fitness.

The effects of prolonged caloric restriction leading to weight-loss on food hedonics and reinforcement.

Evidence suggests that when animals are chronically deprived of calories, the reward of a food stimulus becomes more salient. Recently leptin has been implicated in food reward. The objective of this study was to examine the effect of weight-loss on food hedonics and on the reinforcing value of palatable snack food, and to determine whether plasma leptin concentrations were related to these variables. Fifteen apparently healthy obese adults (n=9 women and 6 men; age=33.5+/-7.8; BMI=35.7+/-1.1 kg/m(2)) were subjected to 8 weeks of caloric deprivation (-700 kcal/day). Plasma leptin (ELISA), body weight and composition (Dual X-ray Absorptiometry), food reinforcement (concurrent schedules task) and food hedonics (visual analogue scale) were measured pre- and post-intervention. Body weight decreased by 5.2+/-2.7% (p=0.001) while leptin decreased by 30.1+/-32.6% (p=0.001). Relative to baseline, after weight-loss food hedonics or "liking" was rated significantly higher for the food reinforcers (p=0.001) offered at sessions end, and this change was not significantly correlated with changes in plasma leptin. No significant effect of weight-loss was noted for the reinforcing value of palatable snack food. In conclusion, after 8 weeks of caloric deprivation there was no change in the reinforcing value of palatable snack foods, but the rating of food "liking" increased ~10%, and this increase was independent of weight-loss.