Scientists at the University of Southern Denmark say adjusting certain parts of the diet may help the body burn more fat, even without eating less or exercising more.
In a recent study, researchers removed two amino acids, methionine and cysteine, from the diets of lab mice. These amino acids are commonly found in animal-based foods such as meat, eggs and dairy. After seven days, the mice on the restricted diet burned more energy than mice on a normal diet.
“The mice that burned the most energy ate the same amount of food as the others, and they didn’t move more or less,” Jan-Wilhelm Kornfeld, a molecular biologist involved in the study, said. “We saw a 20% increase in their thermogenesis. They lost more weight, and it was not because they ate less or exercised more – they simply generated more heat.”
Thermogenesis is the process the body uses to produce heat by burning calories.
It usually increases when someone is exposed to cold temperatures. In fact, the weight loss seen in the study was almost as strong as what happens when mice are kept in freezing conditions.
The researchers found that the extra calorie burning happened in beige fat, a type of fat located just under the skin. It is normally activated when the body is cold; however, in this case, it was activated by diet instead.
“This tells us that beige fat doesn’t care whether the burning is triggered by cold or by diet,” Philip Ruppert, one of the researchers, said.
Methionine and cysteine are more common in animal proteins than in plant-based foods such as vegetables, nuts and legumes. Researchers noted that vegetarians and vegans naturally consume lower amounts of these amino acids. However, the diet tested in this study has only been studied in mice.
“We haven’t tested a methionine/cysteine-restricted diet in humans,” Ruppert said according to a news release. “We can’t say for certain that the same effect would occur in people, but it’s absolutely a possibility.”
Researchers say more studies are needed before any diet recommendations can be made. The findings suggest that certain dietary changes may one day help support weight loss by increasing how much energy the body burns, even without extra exercise.
