Harvard researchers have advice on how to keep from gaining weight. A study published in the New England Journal of Medicine analyzed data collected over two decades from more than 100,000 men and women. Information was collected periodically about what people ate and about exercise, sleep and other lifestyle factors. The scientists found that not all calories are created equal. Not surprisingly, potato chips and French fries packed on the pounds. But so did other forms of potato, including mashed, baked or boiled spuds. One extra serving of potatoes a day led to an extra pound over four years. Sugar-sweetened beverages and refined grains were also culprits.
Is there anything left to eat? The researchers found that people who ate more vegetables, whole grains, yogurt, nuts and fruits were less likely to put on pounds. Physical activity and adequate sleep–between 6 and 8 hours a night–were also associated with a lower likelihood of weight gain.
[New England Journal of Medicine, June 23, 2011]