Researcher Rafael de Cabo said the study “is a very elegant demonstration that even if you are restricting your calories but you are not [eating at the right times], you do not get the full benefits of caloric restriction.”
How metabolism affects aging and lifespan
The researchers conducted a four-year study on hundreds of mice to better understand the ways that fasting, circadian rhythm, and calories affect longevity. One group of mice was allowed to eat as much as they wanted. The second group of mice had their calories cut back by 30-40% and ate on a time-restricted eating schedule.
The researchers learned that the combination of limiting calories and eating meals on a time-restricted schedule was linked with the greatest lifespan improvements. The mice that simply had their calories reduced over the course of the study lived 10% longer, but those that were fed solely at night and also had their calories cut by 40% were able to live 35% longer. The researchers explained that the mice involved in the study typically live for two years, but these mealtime interventions added an extra nine months to their lifespans.
The team pointed out that making these changes to how much the mice were eating and when they were eating was not associated with weight loss. Instead, the improvements in lifespan were the greatest benefits linked with these meal-time changes.
Restricted eating schedules can improve metabolism
Our metabolism becomes less active as we age, and the cells linked to inflammation become more active. The researchers say our goal should be to eat during times when the body is most active while cutting overall calorie intake. This can help improve our metabolism from an aging perspective.
The team hopes to conduct future research in this area to identify other interventions that can help the metabolism long-term.
“If we find a drug that can boost your [circadian] clock, we can then test it in the laboratory and see if that extends lifespan,” said researcher Joseph Takahashi.