A new study suggests that some fruits and vegetables are better for you than others if you want to lose weight. The research, published Sept. 22 in the journal PLOS Medicine, found that as the daily consumption of high-fiber fruit and non-starchy vegetables went up, excessive weight gain went down.
For the study, lead author Monica Bertoia, PhD, of the Harvard T.H. Chan School of Public Health and Brigham & Women’s Hospital in Boston, and her colleagues analyzed the dietary habits and weight changes of 133,468 U.S. men and women. Participants were followed for 24 years as part of several large, long-term studies involving healthcare professionals.
As part of the studies, participants were asked to complete a survey every four years and keep track of the foods they ate each day for a week. The survey asked about 131 specific foods, including fruits and vegetables categorized by fiber, starch and natural sugar content. Participants also reported their weight every two years.
Findings showed that overall those who increased their fruit and vegetable intake over a four-year period tended to lose weight. The fruits with the biggest impact on weight loss included berries, apples and pears. Vegetables like cauliflower, broccoli and cabbage also helped keep weight down.
Erin Keane, a registered dietician and assistant clinical nutrition manager for outpatients at Lenox Hill Hospital in New York City, explained that the difference between starchy and non-starchy vegetables has to do with “glycemic load.”
“Lower glycemic load foods are thought to produce fewer blood glucose spikes, which can decrease hunger and potentially reduce total calorie intake over the course of a day,” Keane told HealthDay. High glycemic load vegetables such as starch-laden potatoes, peas and corn may be less healthy in terms of weight gain, she added.
Although starchy vegetables are rich in nutrients, including potassium, iron, fiber, proteins and vitamins C and B6, they also cause greater increases in sugar levels. These spikes in blood sugar may increase hunger and lead people to eat more. In contrast, high-fiber fruits and vegetables increase feelings of fullness and help people eat less.
The link between greater fruit and vegetable consumption and weight loss held up even after the authors took into consideration factors that would impact weight, including levels of physical activity, the amount of sleep participants got, and if they smoked. They cautioned, however, that the results may not be generalized because study participants were well-educated adults who were more likely to eat healthy foods and practice other healthy behaviors the study did not take into account.
Still, the authors said in a news release, “Our findings support benefits of increased fruit and vegetable consumption for preventing long-term weigh gain and provide further food-specific guidance for prevention of obesity.”