Effects of dietary sugar and of dietary fat on food intake and body fat content in rats.
The long term ingestion of a sugar-rich diet (low fat) caused severe obesity in adult rats. In a separate experiment, the habitual consumption of a fat-rich diet (40% kcal from fat) also caused severe obesity. Severe obesity developed in both groups of animals even though they did not overeat. Voluntary food intake for the sugar-fed rats averaged 28,314 +/- 756 calories/rat per 55 wks which was similar to the value of 28,884 +/- 953 calories/rat per 55 wks for the fat-fed rats. However, both values were lower than that of 32,869 +/- 588 for the control rats eating Purina chow. Despite a lower caloric intake, carcass fat averaged 45 +/- 1% for rats eating the sugar-rich diet and 46 +/- 2% for rats eating the fat-rich diet, but only 33 +/- 2% for rats eating a diet of Purina chow. These results provide evidence that severe obesity can develop in the absence of hyperphagia in animals eating a sugar-rich or fat-rich diet. Finally, a rat model for severe obesity is presented in which carcass fat ranged from 18% (lean) to 61% (severe obesity) using dietary intervention alone at critical stages of the animal's life.
D000273:Adipose Tissue; D000818:Animals; D001823:Body Composition / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D004041:Dietary Fats / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D004435:Eating / Q000187:drug effects*; D002149:Energy Intake; D008297:Male; D009765:Obesity / Q000209:etiology; D051381:Rats; D011919:Rats, Inbred Strains
D004040:Dietary Carbohydrates; D004041:Dietary Fats