Back in 1930, scientists found that animals fed a calorie-restricted diet in the lab had lower chances of developing cancer, diabetes and cardiovascular disease and that they generally lived longer. However, there was no evidence to support the finding in humans until now.

Professor Andrew Dillin from the Salk Institute for Biological Studies in La Jolla, California, managed to identify a gene in roundworms that directly linked calorie restriction to a longer lifespan. He and his team found that the gene called 'pha-4' plays a role in gut development in embryonic worms, but in adults is associated with calorie-restricted longevity. Humans are said to have three genes very similar to pha-4. These genes are in relation to glucagon, which is a pancreatic hormone that increases blood sugar concentration and maintains the body's energy balance, especially during fasting.

Scientists are hoping that this finding will lead to new drugs that would mimic the effects of calorie restriction and allow people to live longer without following severely restricted diets.

Further research will concentrate on monkeys and some time may pass until they realize if dietary restriction would increase longevity in humans.