Scripps Research scientists have discovered why calorie-restricted diets may be effective. And they think the finding could lead to drugs that yield the benefits of dieting, without an actual reduction in eating.
Previous studies have shown that calorie restriction can have life-prolonging benefits by delaying age-related diseases like cancer. That’s because calorie restriction also causes a reduction in body temperature. With less food, the body adapts and tries to use less energy, says Bruno Conti, Scripps Research Biologist and lead scientist on a paper that came out last month in Science Signaling.
“This is probably an adaptive mechanism, because when there’s not much food around, one thing to do is to save energy. You have to consider that a lot of energy up to 50% is used to maintain a high body temperature,” Conti said.
Conti decided to study different groups of calorie-restricted mice in different temperatures to see just how much this reduction in body temperature mattered. And it turns out, the reduction in body temperature could yield most of the benefits of dieting.
“It also contributes to its beneficial effects. In other words, we were able to modify mice genetically so they had a reduction of their body temperature. Even if they ate the same amount of food ... they did have a beneficial effect,” he said.
Conti looked at two groups of calorie-restricted mice. One group was placed in a normal temperature. The other group was placed in another environment, somewhat hotter, where the mice couldn’t experience a reduction in body temperature.
“We found out that actually between 40 and 70% of the changes that occur during calorie restriction are actually due not to the reduction of nutrients, but to the reduction of temperature itself, he said.
Conti suggests scientists could produce a drug that could mimic the effects of reduced temperature in the body to get the same effects as dieting. Though, he says, there is still much work to be done to achieve that.
“It might be possible to enjoy the effects of calorie restriction without having to eat less.”
Conti warned that no one should try to reduce their body temperature themselves.
“I would not recommend anyone to reduce try to reduce body temperature, because if it is not done properly, it can be lethal and detrimental.”
He also says no one should try a calorie restricted diet without consulting their physician.
