FOOD fads come and go. One minute, kale smoothies are the elixir to everything that ails you, the next it is ultra-low-carb lard and offal. But what if the real solution was far more traditional? Meet the latest trend: the “ancestral diet”.

Proponents of the diet say research shows that people have genetic adaptations – such as lactose tolerance – to what would have been their traditional diets. Therefore, a personalised diet, based on what our families ate in centuries past, could be the secret to good health.

All modern health conditions, they say, can be attributed to the …