High-fat dietary restriction in mice induces substrate efficiency and improves metabolic health [Mus musculus]

(Submitter supplied) High energy intake and, specifically, high dietary fat intake challenges the mammalian metabolism and correlates with many metabolic disorders, such as obesity and diabetes. Dietary restriction (DR) is, on the other hand, known to prevent the development of metabolic disorders. The current Western diets are highly enriched in fat and it is as yet unclear whether DR on a certain high-fat (HF) diet elicits similar beneficial effects on health. Here, we report that HF-DR improves metabolic health of mice, compared to mice receiving the same diet on an ad-libitum basis (HF-AL). Already after five weeks of restriction the serum levels of cholesterol and leptin were significantly decreased in HF-DR mice, while their glucose sensitivity and serum adiponectin levels were increased. The body weight and measured serum parameters remained stable in the following 7 weeks of restriction, implying metabolic adaptation. To understand the molecular events associated with this adaptation, we analysed gene expression in white adipose tissue (WAT) with whole genome microarrays. HF-DR strongly influenced gene expression in WAT; in total 8,643 genes were differentially expressed between both groups of mice, with a major role for genes involved in lipid metabolism and mitochondrial functioning. This was confirmed by qRT-PCR and substantiated by an increase in mitochondrial density in WAT of HF-DR mice. These results provide new insights in the metabolic flexibility of dietary restricted animals and suggest the development of substrate efficiency. Limiting food intake by decreasing portion sizes, while maintaining energy sufficiency, may similarly benefit metabolic health in humans