Physical exercise attenuates obesity development in Western-diet fed obese rats independently of vitamin D...

Physical inactivity, associated with the ingestion of hypercaloric foods, contributes to obesity development. In contrast, physical exercise training (ET) can slow obesity progression. Vitamin (Vit) D, a hormone that regulates adipocyte metabolism, may represent a strategy to reduce obesity; however, it is currently not known whether Vit D enhances the anti-obesity benefits of physical exercise. We hypothesized that swimming ET may prevent Western diet (WD)-induced obesity, and that Vit D supplementation could enhance the anti-obesity actions of ET. Male Wistar rats were fed, from 21 to 90 days of age, on a standard diet, or a WD, in association or not (sedentary control [CTL-SED] and WD [WD-SED] groups) with swimming ET for 15 min/day, 3 days a week (exercised CTL [CTL-EXE] and WD [WD-EXE] groups). Additionally, at 60 days of age, half of the CTL-EXE and WD-EXE groups were submitted, or not, to oral Vit D supplementation (CTL-EXE-VD and WD-EXE-VD groups, respectively). At 91 days old, WD-SED rats displayed increased body weight, abdominal adiposity, hypercholesterolemia, hyperleptinaemia and high circulating levels of tumour necrosis factor (TNF)-α. Swimming ET attenuated the increase in abdominal adiposity induced by WD. Furthermore, the WD-EXE group exhibited reductions in glycaemia, triglyceridaemia, cholesterolaemia, leptinaemia and in plasma TNF-α concentrations. Vitamin D supplementation, combined with ET, did not provide any additive benefit against adiposity, only potentiating the effects of ET action on the reduction in triglyceridaemia. Exercise training, independently of Vit D, provides a strategy to attenuate the adiposity expansion that is induced by WD, mediated in part by reductions in leptinaemia and TNF-α levels.