Feeding patterns in rats on restricted access schedules: Palatability, bulk, and other determinants of intake

Abstract

Rats were adapted to 2 h or 4 h restricted daily feeding schedules. The feeding patterns were continuously recorded using a strain gauge. Different groups received different powdered foods, and some groups were switched to different diets at a late stage of adaptation to the original diet. Feeding behavior became continuous throughout a 4-h access when a cellulose diluted diet was presented. In contrast, calorically denser diets were taken in two or three discrete meals during the session. Bitter foods were eaten slowly. The results show that a consideration of different momentary feeding patterns can give more useful insights than a simple measure of the total amount ingested during the session. It is suggested that oral satiety factors or mechanical constraints may pose an upper limit when feeding calorically diluted diets, while postingestive events may limit the intake of denser diets. Liquid diets may be subject to still different constraints.