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 fifth through eighth study examinations (1991-2008) were included in these analyses (3440 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 of annualized weight and waist circumference changes, 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 per day of total dairy had 0.10 kg (±0.04) smaller annualized increment of weight (P(trend)=0.04) than those consuming <1 serving per day. Higher total dairy intake was also marginally associated with less WC gain (P(trend)=0.05). Similarly, participants who consumed ≥3 servings per week of yogurt had a 0.10 kg (±0.04) and 0.13 cm (±0.05) smaller annualized increment of weight (P(trend)=0.03) and WC (P(trend)=0.008) than those consuming <1 serving per week, respectively. Skim/low-fat milk, cheese, total high-fat or total low-fat dairy intake were not associated with long-term change in 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.