The effect of meal frequency and protein concentration on the composition of the weight lost by obese subjects

1. Nitrogen balance, weight loss and resting metabolic rate were measured in thirty-eight obese inpatients on 3.4 MJ (800 kcal)/d diets over 3 weeks.2. All subjects were fed on 13% protein-energy in three rneals/d for the first week.3. In weeks 2 or 3, using a cross-over design, ten subjects were fed on 15 or 10% protein-energy as three meals/d; fourteen subjects were fed on five or one meal/d with 13%protein energy; and fourteen subjects were fed on 15% protein-energy as five meals/d or 10% protein-energy as one meal/d.4. N loss was least on the high-protein week and frequent-meal week: the largest difference was found when these effects were combined (P < 0.001).5. When protein-energy was held constant at 13% N loss decreased significantly (P < 0.01) between week 2 and 3, but when the protein-energy was manipulated there was no significant N conservation in the third week. This suggests that the protein:energy value is more important than meal frequency in the preservation of lean tissue.6. Weight loss was also least on the ‘high-protein’ week and ‘frequent-meal’ week, but this result reached significance only when the effects were combined (P < 0.05).7. Resting metabolic rate decreased with time but was not significantly altered by the dietary regimens.8. Therefore, during the first 3 weeks at an intake of 3.4 MJ/d, a diet with a high-protein concentration, fed as frequent small meals, is associated with better preservation of lean tissue than an isoenergetic diet with lower-protein concentration fed as fewer meals. There was no evidence that meal frequency or protein concentration affect the rate of fat loss.

Meal/Snack Frequencies of College Students: A Normative Study

The behavioral treatment of obesity is based upon the largely unverified theoretical assumption that many forms of overweight are acquired and maintained through deviant eating styles characterized by problems in meal/snack initiation and termination. Since overweight persons are theorized to display an exaggerated responsiveness to salient external stimuli, such as the sight, smell, and taste of food, more frequent meal/snack initiations might be anticipated from persons with weight concerns (Hawkins, 1977). Several recent observational studies (e.g. as recently reviewed by Mahoney, 1975, and Stunkard & Kaplan, 1977) have provided equivocal support for the contention that overweight persons eat at a faster rate in single ingestions occuring in naturalistic or laboratory settings. There is a dearth of information, however, regarding the frequency of meals and snacks for normal and overweight persons in naturalistic contexts. One problem is that such normative studies require the collection of data across several ingestions occurring in different situations.