Eat less to live longer?

“ Not malnutrition. Not starvation. But fasting – allowing our bodies to exist in a state of want, more often than most of us allow in our privileged world of plenty – is unquestionably good for our health and longevity”. With this assumption PhD David Sinclair starts one of the most interesting chapters of his “Lifespan. Why We Age And Why We Don’t Have To”.

Calorie restriction (CR) or eating just enough food to function at a physical level, engages a survival circuit that tell the longevity genes to boost cellular defences, ward off disease and deterioration, minimize epigenetic mutation and slow down aging.

On the island of Okinawa in Japan, famous for its huge number of centenarians, researchers found that people eat 20% fewer calories than in mainland Japan. Not only the lifespan of Okinawans are longer but also they suffer significantly less from cancer, cardiovascular diseases and neurological conditions.

The most difficult thing for these studies is to find healthy and non-obese volunteers able to reduce their food intake substantially and for a quite long period of time. Such studies also raised ethical and methodological issues.

A long-term study of CR in rhesus monkeys showed that 30% of them reached the maximum known lifespan for their specie, comparable to 120 years for a human being. The animals did not live their whole life under this restrictive regime, some of them started the CR as middle-aged.

Generally CR has demonstrated not only to lengthen the lifespan but also to reduce cardiac problems, diabetes and cancer.

There are several ways to restrict the calorie intake in sustainable ways. It does not mean that you have to be hungry all the time but being sometimes hungry engages our survival circuit.

Some of the most popular CR are: intermittent or warrior fasting (12:12 or 16:8), eating 500-700 calories for only 2 days a week (5:2) or fast for a week every quarter.