When it comes to slimming down, a diet low in fat seems to beat a diet low in carbohydrates for body fat loss, new research suggests.
The dilemma over which strategy to adopt has taxed many weight-watchers.
While reducing carbohydrate lowers insulin levels and burns fat, avoiding fatty foods delivered better results overall, scientists found.
The finding stems from a small U.S. National Institutes of Health (NIH) investigation that tracked each approach to weight loss among 19 obese adults.
“Our data and our model suggest that the body doesn’t care that fat calories were cut,” Kevin Hall, a researcher at the National Institutes of Health, said by email.
“It just kept burning the same amount of fat as it did before which led to a substantial imbalance between the fat eaten and burned and therefore body fat loss.”
The result confirmed the predictions of an earlier computer simulation conducted by the same team.
Previous research has found obese people often struggle to shed excess pounds or keep weight off when they do lose it.
Lifestyle changes such as following a healthy diet and getting regular exercise can often help in the short-term but fail to produce lasting results, particularly among people who have a lot to lose before reaching a healthy weight.
"These results counter the claims of the popular theory that has been influencing many people to adopt low-carb diets," said Hall.
That theory focuses on the notion that carb-cutting triggers a decrease in insulin levels, while cutting fat does not. The hormonal plunge should, in turn, boost fat-burning and increase fat loss, he explained.
Body fat loss as a result of dietary fat restriction was significantly greater than that achieved by cutting carbs, the results reported in the journal Cell Metabolism showed. This was despite the fact that more fat was burned with the low carbohydrate diet.
However, the simulations predicted that over long periods of time the body was likely to try to minimize body fat differences between the two diets.
