Cutting out late-night meals or runs to the refrigerator for a snack might well extend our lives — although it might not do much for our waistlines.
Studies in worms, flies, rats and primates have shown that restricting calories can lead to a longer, more healthy life.
In a study of hundreds of mice, Howard Hughes Medical Institute researchers reported that a low-calorie diet during the mice’s most active time (in this case, nighttime) extended their lives by 35%.
The team studied the mice for four years, installing automated feeders that allowed them to control when and how much each rodent ate for its entire life.
Some mice could eat as much as they wanted, while others’ diets were restricted between 30% and 40%. The restricted-diet mice ate on varying schedules, and the ones fed the low-calorie diet at night, during a two- or 12-hour window, lived longest.
The combination of a reduced-calorie diet and eating during active hours added an extra nine months to the mice’s two-year median lifespan.
As animals age, genes linked to inflammation become more active, while genes that regulate metabolism become less so. The mice study showed that reduced calories, taken in during active hours, helped offset those changes in the mice as they aged.
The scientists said they hope learning how calorie restriction affects the body’s internal clocks as we age will help them discover ways to extend humans’ healthy years, potentially through diets or drugs that mimic their effects.
One thing the published study didn’t cover: whether the restricted-calorie mice ever seemed hangry.