Increased consumption of fruits and non-starchy vegetables is inversely associated with weight change, according to a study published this week in PLOS Medicine. The longitudinal study, conducted by Monica Bertoia of Harvard T. H. Chan School of Public Health and Brigham & Women's Hospital, Boston, Massachusetts, and colleagues, shows differences by type of fruit or vegetable, suggesting that characteristics of these foods influence the strength of their association with weight change.
The 2010 Dietary Guidelines for Americans recommend that adults and children should eat a variety of fruits and vegetables to help them achieve and maintain a healthy weight. In this study, Bertoia and colleagues examined associations between changes in the intake of specific fruits and vegetables recorded in dietary questionnaires and self-reported weight changes in 133,468 US men and women followed for up to 24 years in the Nurses' Health Study, Health Professionals Follow-up Study and Nurses' Health Study II.
After adjusting for self-reported changes in other lifestyle factors such as smoking status and physical activity, an increased intake of fruits and of several vegetables was inversely associated with 4-y weight change (-0.53 lb (- 0.24 kg) for each extra daily serving of fruit, -0.25 lb (-0.11 kg) for vegetables). However, starchy vegetables, for example peas (1.13 lb; 95% CI 0.37 to 1.89 lb) and corn (2.04 lb; 95% CI 0.94 to 3.15 lb), were associated with weight gain.
These findings may not be generalizable--nearly all the participants were well-educated white adults, and the use of dietary questionnaires and self-reported weight measurement may have introduced measurement errors. However, study strengths include a very large sample size and long follow-up, with consistent results across three cohorts. The authors state, "our findings support benefits of increased fruit and vegetable consumption for preventing long-term weight gain and provide further food-specific guidance for the prevention of obesity, a primary risk factor for type 2 diabetes, cardiovascular diseases, cancers, and many other health conditions."