Dietary quality predicts adult weight gain: findings from the Framingham Offspring Study.

OBJECTIVE: We tested the hypothesis that dietary quality, measured by adherence to the Dietary Guidelines, was related to weight change in adults. RESEARCH METHODS AND PROCEDURES: Dietary intake was assessed among 2245 adult men and women (average age, 49 to 56 years) in the Framingham Offspring cohort. Three-day dietary records were collected in 1984 to 1988 and again in 1991 to 1996. Weight change was measured over 8 years after each assessment. A five-point diet quality index (DQI) was computed based on mean nutrient intake levels from each set of diet records. One DQI point was contributed for each of five nutrients if intake met Dietary Guidelines for total and saturated fat, cholesterol, sodium, and carbohydrate. Gender-specific generalized estimating equations pooled data across the two assessments to relate DQI to 8-year weight gain.
RESULTS: Men and women with higher DQI scores gained less weight during follow-up (p < 0.05). Average gain over 8 years was approximately 3 pounds among those with highest scores, compared with 5 to 8 pounds among those with lower scores. Smoking cessation was an important predictor of weight gain, accounting for about a 5- to 9-pound difference in weight gain. DISCUSSION: A high-quality diet, one that is consistent with the Dietary Guidelines, may help curb rising rates of obesity at the population level. Poor compliance with the Guidelines, rather than the guidelines themselves, is likely responsible for the weight gain observed in the American population. Adoption of an eating pattern consistent with the Dietary Guidelines should facilitate population weight control if sustained long term.