Effect of 1-year dairy product intervention on fat mass in young women: 6-month follow-up

Objective: Previous results from this laboratory suggest that a 1‐year dairy intake intervention in young women does not alter fat mass. The objective of this study was to determine the impact of the 1‐year dairy intervention 6 months after completion of the intervention. Research Methods and Procedures: Previously, normal‐weight young women (n = 154) were randomized to one of three calcium intake groups: control (<800 mg/d), medium dairy (1000 to 1100 mg/d), or high dairy (1300 to 1400 mg/d) for a 1‐year trial (n = 135 completed). In the current study, 51 women were assessed 6 months after completion of the intervention trial. Body compositions (body fat, lean mass) were measured using DXA. Self‐report questionnaires were utilized to measure activity and dietary intake (kilocalories, calcium). Results: The high‐dairy group (n = 19) maintained an elevated calcium intake (1027 ± 380 mg/d) at 18 months compared with the control group (n = 18, 818 ± 292; p = 0.02). Mean calcium intake over the 18 months predicted a negative change in fat mass (p = 0.04) when baseline BMI was controlled in regression analysis (model R² = 0.11). 25‐Hydroxyvitamin D levels were correlated with fat mass at each time‐point (baseline, r = ?0.41, p = 0.003; 12 months, r = ?0.42, p = 0.002; 18 months, r = ?0.32, p = 0.02) but did not predict changes in fat mass. Discussion: Dietary calcium intake over 18 months predicted a negative change in body fat mass. Thus, increased dietary calcium intakes through dairy products may prevent fat mass accumulation in young, healthy, normal‐weight women.