Most people know eating fruits and vegetables is good for their health, and better for keeping pounds off than, say, a cheeseburger. But this conventional wisdom is nuanced: some fruits and vegetables are better for weight loss than others, and some are even associated with weight gain. Published in PLoS One, the research examined data from 133,468 men and women who took part in three separate studies over a 24-year period: the Nurses’ Health Study, the Nurses’ Health Study II, and the Health Professionals Follow-up Study. During the 24-year period, participants were asked to complete a food-frequency questionnaire covering 131 separate food items, including a range of fruits and vegetables, every four years. After taking into account various lifestyle factors such as smoking and physical activity level, here is what the researchers found when they evaluated the amount of fruits and vegetables consumed by the participants:
In general, each extra serving of fruit per day was associated with an almost 0.50 lb weight decrease over a four-year period. The association was strongest for berries, apples, and pears.
In general, each extra serving of vegetables per day was associated with a 0.25 lb weight decrease over a four-year period. The association was strongest for cruciferous vegetables (such as cauliflower and broccoli) and green leafy vegetables (such as kale, spinach, and romaine lettuce).
Starchy vegetables, such as corn, peas, and potatoes, had the opposite effect: more servings were associated with weight gain. However, there was one exception to this trend: starch-containing tofu and soy products were associated with weight loss.
These findings indicate that simply eating more fruits and vegetables may not be enough for weight loss—choosing the right fruits and vegetables is key. The high-fiber content and low-glycemic load of some fruits and vegetables could explain why this is the case—high-fiber foods tend to increase feelings of fullness, and contribute fewer calories to a meal. And while potatoes and corn do contain fiber, they also contain more calories than other types of vegetables. However, more research is needed to determine if starchy vegetables actually contribute to weight gain directly, or whether people who eat more starchy vegetables tend to share unhealthy habits which are responsible for any weight gain.
Source: PLoS One