MEAL PATTERN OF RATS DURING HYPERPHAGIA INDUCED BY LONG-TERM FOOD RESTRICTION IS AFFECTED BY DIET COMPOSITION

The influence of diet composition on feeding behavior during the hyperphagia induced by about 15% loss in body weight due to restricted feeding (5 g food/day for 7 days) was investigated in adult male rats. Rats were fed either a low-fat, high-carbohydrate diet (LF diet), a medium-fat diet (MF diet) or a carbohydrate-free, high-fat diet (HF diet). The transient hyperphagia resulting from food restriction was greater in LF- and MF-rats than in HF-rats, in which a mild hypophagia was observed following the hyperphagia. Recovery of body weight was imperfect in the HF-rats in comparison to the unrestricted controls. During the hyperphagia, the meal pattern of LF- and MF-rats was mainly characterized by an increase in meal size, whereas HF-rats showed an increase in meal frequency. These observations indicate that control of food intake by body weight in LF- and MF-rats occurs mainly by modulation of the mechanisms producing meal-ending satiety, whereas in HF-rats the mechanisms eliciting meal initiation seem to be affected by body weight.