Dairy products do not lead to alterations in body weight or fat mass in young women in a 1-y intervention

Background: Previous results suggested that increased intake of dairy calcium is associated with reduced weight and fat mass. Objective: The purpose of this study was to determine whether long-term increases in consumption of dairy calcium alter body weight and fat mass in young, healthy women. Design: We used a randomized, 1-y intervention for dairy calcium. Subjects were 155 young (aged 18-30 y), healthy, normal-weight women with intake of dietary calcium < 800 mg/d and energy intake <= 2200 kcal/d. Women were randomly assigned to 1 of 3 groups: 1) control: continue established dietary intake; 2) medium dairy: substitute dairy products to achieve intake of calcium of approximate to 1000-1100 mg/d and maintain isocaloric intake; 3) high dairy: substitute dairy products to achieve intake of calcium of 1300-1400 mg/d and maintain isocaloric intake. The main outcome measures were 1-y changes in body weight (in kg) and fat mass (in kg). One hundred thirty-five women completed the trial. Results: Mean intakes of calcium during the intervention were 742.4 +/- 321.5, 1026.4 +/- 311.3, and 1131.29 +/- 337.2 mg/d for the control, medium-dairy, and high-dairy groups, respectively (P < 0.0001). No significant differences were observed in the mean 1-y change in body weight between the control, medium-dairy, and high-dairy groups (0.8 +/- 2.8, 0.7 +/- 3.0, and 1.5 +/- 4.1 kg, respectively; P = 0.45). No significant differences were observed in the mean 1-y change in fat mass between the control, medium-dairy, and high-dairy groups (-0.5 +/- 2.5, 0.3 +/- 2.7, and 0.5 +/- 3.5 kg, respectively; P = 0.26). Conclusion: Increased intake of dairy products does not alter body weight or fat mass in young, healthy women over 1 y.