Calcium Supplementation for a Healthy Weight (CaSHeW)

The prevalence of obesity and levels of overweight is rising worldwide. In the United States, 63% of men and 55% of women are now overweight or obese. Recent epidemiological data and clinical trials have shown that a small daily increase in calcium or dairy products may result in annual losses in body weight and body fat. Data from clinical studies suggest that a 1000 mg per day increase in calcium intake is associated with an 8 kg difference in mean body weight and that calcium intake explains about 3% of the variance in body weight. The objective of this study is to investigate the effect of calcium (Ca) and vitamin D (D) supplemented orange juice (OJ) on weight loss and visceral fat mass in overweight and obese adults. Otherwise healthy overweight and obese men and women ages 18 to 65 years with a BMI between 25 and 35 kg/m2 will be randomized into one of the following experimental groups (36 in each group): 1. Regular OJ: one 8 fluid oz serving three times/day (control) 2. Regular OJ fortified with Calcium (350 mg/8 fluid oz serving) and Vitamin D3 (100 IU/8 fluid oz serving): one 8 fluid oz serving three times/day (treatment) Subjects will receive either orange juice (OJ) (control) or OJ fortified with calcium and vitamin D3 (treatment) for 16 weeks. The study will involve 6 outpatient study visits to the study center. Primary endpoint: Change in body weight after 16 weeks Secondary endpoint: Visceral fat change after 16 weeks as measured by single slice CT scan