
According to the Bible, Adam lived for hundreds of years, and in Hindu mythology lifespans of thousands of years are commonplace. Perhaps this is because the ancients ate no junk food and got more exercise herding their cattle. They didn’t have as much to eat. Yoga masters, for instance, heirs of an ancient healing tradition, will tell you to stop eating before you feel full. It’s long been thought that restricting food intake can extend lifespan.
In a 1930s US study, rats on a calorie-restricted diet were found to live twice as long as normal. Those findings have since been tested on other animals and found to hold generally true. However, there has been no scientific evidence until now to show that the same holds true in humans.
The mechanisms of ageing are still not understood, but the thinking goes that consuming less means the body can more efficiently break down and absorb nutrients, minimizing the storage of excess as fat. This helps stabilize blood sugar levels, reduces strain on the organs, and also means less free radicals, hence lower oxidative damage (suspected of causing cancers).
But just eating less is not enough: one has to eat nutritious food and live a healthy lifestyle. Simply eating too little can cause malnutrition, which actually speeds up aging.