Dietary calcium attenuation of body fat gain during high-fat feeding in mice

Human epidemiological studies have supported the hypothesis that a dairy food-rich diet is associated with lower fat accumulation, although prospective studies and intervention trials are not so conclusive and contradictory data exist in animal models. The purpose of this study was to assess the effects on body weight and fat depots of dairy calcium (12 g/kg diet) in wild-type mice under ad libitum high-fat (43%) and normal-fat (12%) diets and to gain comprehension on the underlying mechanism of dairy calcium effects. Our results show that calcium intake decreases body weight and body fat depot gain under high-fat diet and accelerates weight loss under normal-fat diet, without differences in food intake. No differences in gene or protein expression of UCP1 in brown adipose tissue or UCP2 in white adipose tissue were found that could be related with calcium feeding, suggesting that calcium intake contributed to modulate body weight in wild-type mice by a mechanism that is not associated with activation of brown adipose tissue thermogenesis. UCP3 protein but not gene expression increased in muscle due to calcium feeding. In white adipose tissue there were effects of calcium intake decreasing the expression of proteins related to calcium signalling, in particular of stanniocalcin 2. CaSR levels could play a role in decreasing cytosolic calcium in adipocytes and, therefore, contribute to the diminution of fat accretion. Results support the anti-obesity effect of dietary calcium in male mice and indicate that, at least at the time-point studied, activation of thermogenesis is not involved.