The Experiment That Started It All

Researchers gave rats a carefully limited diet while providing the nutrients they needed. They compared these rats with rats allowed to eat as much as they wanted. The rats eating less lived longer and showed fewer signs of aging. This was an animal study, so it does not directly show that calorie restriction extends human life.

What this means for you: This experiment helped start research into calorie restriction, but it is not a reason to follow a very low-calorie diet. Severe restriction can cause harm, and the human benefits remain uncertain.