Vagotomy in the rat reduces meal size of diets containing fat

This study was designed to examine the possibility that the presence of rat in a diet is responsible for preventing the small post vagotomy meals that occur with chemically defined low fat liquid diets but not with lab chow diets. Rats were thoroughly adapted to four liquid diets varying in fat content from virtually 0 to 30 g per 100 ml. They were then subjected to an operation designed to destroy the vagus nerves. All animals who were shown in post mortem tests to have suffered vagal damage also showed reduced meal sizes on all the diets. The meal sizes of animals for whom there was no evidence of vagal damage were normal. It was concluded that bulk rather than fat content is responsible for preventing the reduced post vagotomy meals.