Abstract P271: Diet in Association with Weight Change and the Development of Overweight and Obesity - A Prospective Study of Men

Abstract

Background: Obesity has become an epidemic affecting all age and socioeconomic groups worldwide with tremendous health consequences. Research is needed to determine modifiable lifestyle factors, including dietary factors, to prevent adults from becoming overweight or obese. Hypothesis: Diet is associated with weight change and overweight and obesity development. Methods: The Harvard Alumni Health Study is a prospective cohort study of men who matriculated at Harvard University from 1916-1950, and who have been followed by periodic questionnaires since 1962. We studied 6614 men free of cancer, cardiovascular disease, and diabetes (mean age, 65.5 years) who were nonobese (body mass index (BMI) <30 kg/m 2 ) based on a 1988 questionnaire that also inquired about lifestyle, clinical, and dietary factors (23-item food frequency questionnaire). We considered individual dietary factors and a derived Dietary Approaches to Stop Hypertension (DASH) score of 6 dietary components: high intake of fruits, vegetables, fish, and low-fat dairy products, and low intake of sweets and red/processed meats). Men reported body weight on follow-up questionnaires in 1993 and 1998; 5- and 10-year body weight changes were computed along with the odds ratios (ORs) (95% confidence intervals (CIs)) of becoming overweight or obese, adjusting for various lifestyle and clinical factors as well as baseline BMI. Results: Over a 10-year period, 631 of 3906 initially normal weight (BMI≤25 kg/m 2 ) men became overweight or obese, and 230 of 6614 men initially nonobese (BMI≤30 kg/m 2 ) became obese. The multivariable-adjusted 5-year mean changes in body weight (standard deviation) were 0.03 (0.12), -0.12 (0.07), and -0.36 (0.09) kg, among men consuming total dairy products ≤6 times/week, 1-2 times/day, and ≥3 times/day (P-trend: 0.009), respectively, primarily driven by high-fat dairy intake (P, trend = 0.02). These associations weakened for 10-year weight changes. Higher tea consumption was inversely associated with greater 10-year (P-trend = 0.04), but not 5-year, weight loss. Among initially normal weight men, alcohol intake was inversely associated with a lower odds of becoming overweight or obese (OR (95% CI) for ≥168 versus 0 grams/week, 0.69 (0.49, 0.98); P, trend = 0.08). Other individual dietary factors were not associated with the odds of becoming overweight or obese. When investigating a combination of 6 beneficial dietary factors derived from the DASH score, an inverse linear association was observed with a lower OR of becoming obese (P-trend = 0.048), but not for becoming overweight or obese. Conclusion: In this prospective study of older men, selected individual dietary factors as well as a broader score reflecting a beneficial diet was related to less weight gain and lower odds of becoming overweight or obese.