BUTTER FOR BRAINS

hen low-fat was the religion, no one would ever have predicted a health craze for breakfasting on a 500-calorie cup of coffee blended with spoonfuls of butter and saturated coconut oil. “Bulletproof coffee” is the idea of the American entrepreneur Dave Asprey, who thought of it while trekking in Tibet, where they drink yak-butter tea. Asprey claims that buttery coffee will reduce cravings for carbohydrates such as toast and programme the body to “burn fat for energy all day long”.

Reader, I tried it. Butter and coffee are two of my favourite substances. But I was taken aback by the sheer vileness of my homemade approximation of bulletproof coffee. The butter coated my tongue like an oil slick. If my appetite was reduced, it was because this dense buff-coloured froth left me nauseated. Never again.

There will always be fad diets and there will always be people desperate enough to try them. The interesting thing about bulletproof coffee, however — and it has thousands of devotees — is that it shows just how fashionable butter has become.

For years we were told to avoid saturated fat for the sake of our hearts and waistlines. We ate it anyway, but guiltily. Now, though, butter has become a kind of golden elixir, something so “healthy” that some feel compelled to swallow it down with the morning coffee like a vitamin.

In February a study led by Zoë Harcombe published in the journal Open Heart concluded that the official UK guidelines on dietary fat — which still form the cornerstone of National Health Service advice — were based on a faulty reading of the evidence. Harcombe points out that the official low-fat government advice, introduced in 1983, “wasn’t tested, let alone proven”. Harcombe’s study has given fresh ammunition to the new