Massachusetts – A new study, conducted by a team of Harvard scientists and published in the journal PLoS Medicine, showed that eating more vegetables and fruit can decrease long-term weight gain. It also suggested that specific types can either help or not to weight loss.

Researchers examined data on more than 133,000 women and men in the US, who were followed every four years between 1986 and 2010, and found that those who ate an extra handful of blueberries daily lost more than half a kilogram after 4 years.

On the other side, consumption of corn or starchy vegetables, such as peas and potatoes, increased weight gain for nearly a kilogram over a four-year period. Fruits like apples, pears, strawberries and grapes, and vegetables like beans and broccoli benefited someone’s efforts to lose weight.

Variety of fruits and vegetables at fruit stand at Thai weekend market. Credit: Bryan Busovicki/123rf

“The benefits of increased consumption were greater for fruits than for vegetables and strongest for berries, apples/pears, tofu/soy, cauliflower, and cruciferous and green leafy vegetables,” wrote lead author Monica Bertoia from Harvard’s School of Public Health in the latest PLOS Medicine study.

From these results, researchers concluded that the consumption of fruits and vegetables with a higher level of fiber or lower glycemic content may contribute to keeping a healthier weight than the consumption of those with lower fiber content or higher glycemic load.

This is explained by the fact that high fiber foods increase the feeling of fullness after eating, which can reduce total energy intake. Foods that contain a low glycemic load produce smaller and fewer sugar spikes after they are consumed, which also reduces appetite.

“Although these vegetables have nutritional value (potassium, vitamin C, vitamin B6, iron, fiber, and protein), they have a higher glycemic load (lower carbohydrate quality) that could explain their positive association with weight change,” wrote Bertoia. “Increased satiety with fewer calories could be partly responsible for the beneficial effects of increasing fruit and vegetable intake.”

Nonetheless, these results can not suit everyone. Nearly all the participants in the experiment were well-educated white adults, and the dietary questionnaires and self-reported weight measurement used may have thrown some mistakes. Also, these individuals may have particular characteristics that were in fact responsible for their weight loss but were not taken into account.

Source: PLoS Medicine