High dietary calcium does not mediate the effects of dairy to attenuate weight gain and improve glucose tolerance in mice with pre‐existing obesity

Abstract

Previous research in animal models suggests increased dietary Ca and dairy reduces weight gain and obesity‐associated inflammation. Effects of these dietary factors on obese phenotypes when introduced in the context of pre‐existing obesity are less clear. We investigated the effects of introducing high calcium (HC) and HC with non‐fat dry milk (NFDM) in adult male C57BL/6J mice pre‐fattened with an obesigenic, pro‐inflammatory high fat diet (45% kcal; HFD) for 12 wks. Mice were then assigned (n=30/group) to one of three macronutrient‐matched HF diets for an additional 8 wks: control (0.5%; CON), HC (1.5% Ca), or HC with NFDM. Surprisingly, HC mice gained more wt (10.1 + 0.5 g vs. 5.3 + 0.4 g; P<0.001) with a significantly higher feed efficiency (12.8 + 0.5 mg wt gain/kcal intake) and decreased glucose tolerance (GT) compared to CON. NFDM mice gained the least wt (2.2 + 0.6g; P<0.001) with a lower feed efficiency (3.0 + 0.6 vs. 7.8 + 0.4 mg wt gain/kcal intake) and improved GT vs. CON. Obesity‐related inflammatory markers are currently being analyzed. We conclude that effects of dairy to reduce weight gain and improve glucose tolerance in mice with pre‐existing obesity and fed a HFD is not mediated by dietary Ca, and likely results from other factors specific to the NFDM diet.Grant Funding Source: National Dairy Council and ARS Project 5306–51530–016–00D