BETHESDA, Md., Aug. 13 (UPI) -- Researchers found that cutting dietary fat led to a 68 percent greater weight loss than cutting the same number of carbohydrate calories in a new National Institutes of Health study.
While cutting fat led to higher weight loss, the researchers say that both can have positive effects on health and reducing body fat, and that the best choice of diet is one that the person can maintain over time.
"Compared to the reduced-fat diet, the reduced-carb diet was particularly effective at lowering insulin secretion and increasing fat burning, resulting in significant body fat loss," said Dr. Kevin Hall, a researcher at the National Institute of Diabetes and Digestive and Kidney Diseases, in a press release. "But interestingly, study participants lost even more body fat during the fat-restricted diet, as it resulted in a greater imbalance between the fat eaten and fat burned. These findings counter the theory that body fat loss necessarily requires decreasing insulin, thereby increasing the release of stored fat from fat tissue and increasing the amount of fat burned by the body."
Researchers confined 19 obese men and women to a metabolic ward for two two-week periods. The participants were fed a baseline diet for five days, and then were randomly either fat- or carbohydrate-restricted diets for six days. After another five-day baseline diet, the participants then received the diet they had not had during their first stay.
Participants bodies on the carbohydrate-restricted diet led to increased fat oxidation and losses of about 53 grams of fat per day. With the fat-restricted diet, however, participants' fat oxidation was unchanged at about 89 grams of fat per day.
"Our data tell us that when it comes to body fat loss, not all diet calories are exactly equal," Hall said. "But the real world is more complicated than a research lab, and if you have obesity and want to lose weight, it may be more important to consider which type of diet you'll be most likely to stick to over time."
The study is published in Cell: Metabolism.