Food restriction may not reduce leptin gene expression in obesity condition – A study with reference to an animal model of obesity, WNIN/Ob

Abstract

Objective: Leptin an adipokine, deregulated in many cases of obesity is poorly understood under nutrition interventional strategies like food restriction. The present study addresses the above with the help of a rodent animal model of obesity, WNIN/Ob Methods: Male rats of WNIN/Ob aged 35 days were allotted to three groups (n=4): (1) Rats with lean phenotype and fed ad libitum, (2) Rats with obesity phenotype and fed ad libitum, and (3) Rats with obesity phenotype and subjected to 60% food restriction. Rats were fed up to 90 days age, after which they were assessed for body weights, fat percentages and leptin. Results: The higher body weights and fat percentages, in rats with obesity phenotype were reversed by food restriction to that of lean phenotype. Circulating leptin levels though showed a significant reduction (1.7 fold), they were significantly high (43 fold) compared to lean phenotype. The relatively high leptin gene expression in food restricted versus ad libitum fed ones (11 fold versus 4 fold with respect to lean) explains the higher circulating leptin levels. Conclusions: Results suggest that mere food restriction may not reduce leptin gene expression and hence may not be a safer practice to reduce obesity.