Eating less may not extend life of lean people

Caloric restriction may not be a universally beneficial anti-aging strategy, as commonly believed, according to a new study in mice.

Caloric restriction may not be a universally beneficial anti-aging strategy, as commonly believed, according to a new study in mice.

Researchers said that the anti-aging strategy known as caloric restriction may help obese people but for lean humans, eating less may be a pointless, frustrating and even dangerous exercise.

“Today there are a lot of very healthy people who look like skeletons because they bought into this,” said Raj Sohal, professor at the University of Southern California’s School of Pharmacy.

For the study, Sohal and Michael Forster, of the University of North Texas Health Science Center, compared the life span and caloric intake of two genetically engineered strains of mice.

Sohal said that the ‘fat’ strain, known as C57BL/6, roughly doubles in weight over its adult life. That strain benefited from caloric restriction.

The ‘lean’ strain, DBA/2, does not become obese. Caloric restriction did not extend the life of these mice, confirming previous work by Forster and Sohal.

“Our study questions the paradigm that caloric restriction is universally beneficial. Contrary to what is widely believed, caloric restriction does not extend (the) life span of all strains of mice,” Sohal said.

The results appeared online Jan. 13 in advance of print publication in The Journal of Nutrition.