Not all calories are created equal, according to a study from Tufts University in Boston. Dietary intakes were gathered on almost 121,000 adults. During the following 24 years, people’s weight crept up, but the odds of unwanted pounds differed depending on the typical types of protein and carbs. Granted, people who ate lots of nuts, peanut butter, fish, yogurt, and low-fat cheese tended to lose weight. However, other foods often considered unhealthy, such as full-fat cheese, eggs, and whole milk, had little influence on weight. The foods that caused the most weight gain were sugary beverages and refined or starchy carbohydrates, including white bread, potatoes, and white rice. In general, adults gained more weight as the glycemic load of their diets increased. For example, every 50-unit increase in a person’s glycemic load (the equivalent of two bagels) was associated with an extra pound gained over four years. Eggs and cheese were connected to weight gain only if people also consumed more refined grains. The researchers warn against focusing too much on calories, since it is where those calories are coming from that may be the most important message.
A study from the National Institute of Diabetes and Digestive and Kidney Diseases found that some overweight dieters have a “thrifty gene,” making it more difficult to lose weight, and requires greater efforts when they diet and increase daily activity.
In Perspective: While the thrifty-gene study is interesting, it should be noted that the National Weight Control Registry, which follows successful dieters who have lost a significant amount of weight and kept the weight off, reports that gaining excess body fat appears to be the culprit. Accumulating too much body fat may permanently alter body metabolism, or at least make it resistant to weight loss. The NWCR has found those people must exercise more to lose and maintain a weight compared to lean folks who never gained the weight to begin with.
Smith J, Hou T, Ludwig D, et al: Changes in intake of protein foods, carbohydrate amount and quality, and long-term weight change. American Journal of Clinical Nutrition 2015;April 8th.
Reinhardt M, Thearie M, Ibrahim M, et al: A human thrifty phenotype associated with less weight loss during caloric restriction. Diabetes 2015; May 11th.