After confining 19 adults with obesity to a metabolic ward for 2 two-week periods, scientists at the National Institutes of Health found that when the test subjects cut dietary fat intake they lost more weight than those who cut carbohydrates.
“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 Kevin Hall, Ph.D., senior investigator with the National Institute of Diabetes and Digestive and Kidney Diseases and lead study author.
“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.”
Health scientists have conducted a plethora of studies pitting low-fat diets against low-carb diets, but results can be flawed due to the 'guinea pigs' straying from the assigned diets or mis-reporting in food diaries, so a highly controlled trial such as this is notable.
What are the implications of these findings?
Kevin Hall, Ph.D., Senior investigator with the National Institute of Diabetes and Digestive and Kidney Diseases at the National Institutes of Health and lead study author