The fasting track to excellent health

Fasting regimes such as the 5:2 diet could help the body guard against diseases including cancer, diabetes and Alzheimer's.

Eating three meals a day plus snacks is "abnormal" in terms of human evolution and is at odds with the body's natural rhythms, a study in the Proceedings of the National Academy of Sciences said.

It called on doctors to encourage "intermittent energy restriction", such as the 5:2 diet, on which people eat normally for five days and then consume 500 calories for two days.

This can help the body break down fat and repair cells, reversing the ageing process, shrinking tumours and guarding against neuron damage, researchers said.