The ultra-low-carb ketogenic diet – which forces the body to burn fat – flies in the face of conventional nutritional advice. It is hugely popular, but is it healthy or sustainable?
This time last year, Google searches for the keto diet outranked those for paleo for the first time. Twelve months on, keto recipe books are flying high in the publishing charts, there are emerging permutations (vegan-keto, the vegetable-heavy ketotarian) and a new industry of high-fat snacks aimed at fans is booming.
A ketogenic diet (or keto) is predominantly made up of high-fat foods – including butter, oils, meat, fish, eggs and cheese – and very low-carb vegetables such as cauliflower and leafy greens. This forces the body to burn fat for fuel, rather than glucose. In order to maintain that state, known as ketosis, followers typically restrict their carbohydrate intake to less than 50g a day. And, as protein can also be broken down into glucose, that has to be restricted, too.