Meal size of high-fat food is reliably greater than high-carbohydrate food across externally-evoked single-meal tests and long-term spontaneous feeding in rat.
A series of studies in rat using isoenergetic (kcal/ml) liquid diets differing in fat content has previously found dietary fat to dose-dependently increase daily caloric intake. In single-meal tests in which meal initiation was externally evoked in feeding-associated environments, the behavioral expression of this overeating was found to be larger meal intake. The present studies confirmed the ecological validity of this larger meal size of high-fat diet (HF) relative to high-carbohydrate diet (HC): meal size of HF>HC in home-cage testing (Experiment 1), and during undisturbed, spontaneous feeding in which ingestive behavior was continuously monitored (Experiments 2 and 3). These findings demonstrate that single-meal paradigms yield results consistent with spontaneous feeding of high-fat and high-carbohydrate liquid diets, thus supporting the use of single-meal studies to better understand the physiological bases of elevated caloric intake associated with chronic consumption of a high-fat diet.
Synowski
Stephen J
SJ
Department of Psychology, UMBC, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
Smart
Andrew B
AB
Warwick
Zoe S
ZS
D000818:Animals; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D002149:Energy Intake; D005247:Feeding Behavior / Q000523:psychology*; D008297:Male; D051381:Rats; D020318:Rats, Long-Evans; D015203:Reproducibility of Results
D004040:Dietary Carbohydrates; D004041:Dietary Fats