According to a National Institutes of Health study, cutting fat from your diet leads to more fat loss than reducing carbs.

Scientists intensely analyzed people on controlled diets by inspecting every morsel of food, minute of exercise and breath taken.

Both diets, analyzed by the National Institutes of Health, led to fat loss when calories were cut, but people lost more when they reduced fat intake.

Experts say the most effective diet is one people can stick to.

It has been argued that restricting carbs is the best way to get rid of a “spare tire” as it alters the body’s metabolism.

The theory goes that fewer carbohydrates lead to lower levels of insulin, which in turn lead to fat being released from the body’s stores.

“All of those things do happen with carb reduction and you do lose body fat, but not as much as when you cut out the fat,” said lead researchers Dr. Kevin Hall, from the US-based National Institute of Diabetes and Digestive and Kidney Diseases.

In the study, 19 obese people were initially given 2,700 calories a day.

Then, over a period of two weeks they tried diets which cut their calorie intake by a third, either by reducing carbs or fat.

The team analyzed the amount of oxygen and carbon dioxide being breathed out and the amount of nitrogen in participants’ urine to calculate precisely the chemical processes taking place inside the body.

The results published in Cell Metabolism showed that after 6 days on each diet, those reducing fat intake lost an average 463g of body fat – 80% more than those cutting down on carbs, whose average loss was 245g.

Dr. Kevin Hall said there was no “metabolic” reason to chose a low-carb diet.

However, studies suggest that in the real world, where diets are less strictly controlled, people may lose more weight by reducing carbohydrate intake.

Dr. Kevin Hall is now analyzing brain scans of the participants to see how the diets affect how rewarding food is.