Effect of food deprivation and maintenance diet composition on fat preference and acceptance in rats

High-fat diets typically elicit greater kcal intake and/or weight gain than low-fat diets. Palatability, caloric density, and the unique postingestive effects of fat have each been shown to contribute to high-fat diet hyperph agia. Because long-term intake reflects the sum of many individual eating e pisodes (meals), it is important to investigate factors that may modulate f at intake at a meal. The present studies used high-fat (hi-fat) and high-ca rbohydrate (hi-carb) liquid diets (both 2.3 kcal/mL) to assess the effect o f hunger level (0 versus 24-h food deprivation) and fat content of the main tenance diet (12 versus 48%) on fat preference (when a choice among foods i s offered in a two-bottle test), and acceptance (only one food offered) in male rats. Preference for hi-fat relative to hi-carb (two-bottle test) was enhanced by 24-h food deprivation, and by a high-fat maintenance diet. In c ontrast, neither deprivation nor maintenance diet composition influenced re lative meal size (one-bottle test) of hi-fat and hi-carb: irrespective of t est conditions, meal size of hi-fat was bigger than meal size of hi-carb. ( C) 1999 Elsevier Science Inc. All rights reserved.