High-fat diet Influences on Sleep Regulation: Lessons From Animal Studies

The interaction between a high-fat diet (HFD) and sleep regulation takes place against the common background of metabolism, at a hypothalamic level. Typical sleep modifications observed in laboratory rodents kept under an HFD regimen, compared to normal fed controls, are: a lower daily amount of wakefulness mirrored by a higher amount of non-REM sleep that is also more fragmented and of a worse quality. REM sleep amount is mildly augmented in HFD-fed animals. The circadian distribution of the wake-sleep cycle is also modified and HFD also interferes with clock gene regulation. The opposite interaction is also true: prolonged sleep modifications may alter feeding behavior. These complex interactions involve different hypothalamic structures, but among these, the orexinergic system of the lateral hypothalamus may have a primary role. Animal models help to shed light on these processes, possibly suggesting more efficient approaches that can be considered in the treatment and prevention of obesity and metabolic syndromes.