Response of adult lean and obese female Zucker rats to intermittent food restriction/refeeding.
Previously, it was found that lean and obese Zucker rats (9-15 wk of age) responded differently to the first of four cycles of food restriction/refeeding. In later cycles, they responded similarly. The present study was undertaken to determine if this finding was due to age, adaptation to the intervention or the obesity. Adult (35-wk-old) lean and obese rats were classified into four groups, ad libitum-fed lean and obese and food-restricted lean and obese. Food-restricted rats underwent four 3-wk periods when they were fed 50% of their ad libitum intake, each followed by a 3-wk period of ad libitum refeeding. Food-restricted rats lost and regained sufficient weight in each cycle to weigh a similar amount as their ad libitum-fed groups by the end of each refeeding period. In lean rats, there were no permanent effects of this intervention except for a 25% reduction in carbohydrate intake. Similar results were found in obese rats, although they did have significantly lower retroperitoneal fat pad weight and serum triacylglycerol levels than ad libitum-fed obese rats at the end of the experiment. These results indicate that lean and obese adult rats respond to each food restriction/refeeding cycle in a similar manner. Results in the earlier experiment would appear to be due both to age and genotype.
D000222:Adaptation, Physiological; D000273:Adipose Tissue / Q000503:physiopathology; D000818:Animals; D001835:Body Weight; D005260:Female; D005502:Food; D005508:Food Deprivation / Q000502:physiology*; D008099:Liver / Q000201:enzymology; D009765:Obesity / Q000378:metabolism / Q000503:physiopathology*; D009929:Organ Size; D051381:Rats; D011924:Rats, Zucker