Dairy augmentation of total and central fat loss in obese subjects

BACKGROUND AND OBJECTIVE: We have previously demonstrated an antiobesity effect of dietary Ca; this is largely mediated by Ca suppression of calcitriol levels, resulting in reduced adipocyte intracellular Ca2+ and, consequently, a coordinated increase in lipid utilization and decrease in lipogenesis. Notably, dairy Ca is markedly more effective than other Ca sources. DESIGN: Obese subjects were placed on balanced deficit (-500 kcal/day) diets and randomized to control (400-500 mg Ca/day; n = 16) or yogurt (1100 mg Ca/day; n = 18) treatments for 12 weeks. Dietary macronutrients and fiber were held constant at the US average. MEASUREMENTS: Body weight, body fat and fat distribution (by dual-energy X-ray absorptiometry), blood pressure and circulating lipids were measured at baseline and after 12 weeks of intervention. RESULTS: Fat loss was markedly increased on the yogurt diet (-4.43 +/- 0.47 vs -2.75 +/- 0.73 kg in yogurt and control groups; P < 0.005) while lean tissue loss was reduced by 31% on the yogurt diet. Trunk fat loss was augmented by 81% on the yogurt vs control diet (P < 0.001), and this was reflected in a markedly greater reduction in waist circumference (-3.99 +/- 0.48 vs -0.58 +/- 1.04 cm, P < 0.001). Further, the fraction of fat lost from the trunk was higher on the yogurt diet vs control (P < 0.005). CONCLUSION: Isocaloric substitution of yogurt for other foods significantly augments fat loss and reduces central adiposity during energy restriction.