Longitudinal association between dairy consumption and changes of body weight and waist circumference: the Framingham Heart Study

BACKGROUND: Dairy foods are nutrient-dense and may be protective against long-term weight gain. OBJECTIVE: We aimed to examine the longitudinal association between dairy consumption and annualized changes in weight and waist circumference (WC) in adults. METHODS: Members of the Framingham Heart Study Offspring Cohort who participated in the 5(th) through 8(th) study examinations (1991–2008) were included in these analyses (3,440 participants with 11,683 observations). At each exam, dietary intake was assessed by a validated food frequency questionnaire, and weight and WC were assessed following standardized procedures. Repeated measures models were used for the longitudinal analyses by adjusting for time-varying or invariant covariates. RESULTS: On average, participants gained weight and WC during follow-up. Dairy intake increased across exams. After adjusting for demographic and lifestyle factors (including diet quality), participants who consumed ≥3 servings/d of total dairy had 0.10 [±0.04] kg smaller annualized increment of weight (P(trend)=0.04) than those consuming <1 serving/d. Higher total dairy intake was also marginally associated with less WC gain (P(trend)=0.05). Similarly, participants who consumed ≥3 servings/wk of yogurt had a 0.10 [±0.04] kg and 0.13 [±0.05] cm smaller annualized increment of weight (P(trend)=0.03) and WC (P(trend)=0.008) than those consuming <1 serving/wk, respectively. Skim/low-fat milk, cheese, total high-fat or total low-fat dairy intake was not associated with long-term change of weight or WC. CONCLUSION: Further longitudinal and interventional studies are warranted to confirm the beneficial role of increasing total dairy and yogurt intake, as part of a healthy and calorie-balanced dietary pattern, in the long-term prevention of gain in weight and WC.