“A few tens of thousands of physicians are now prescribing these diets,” says Taubes, speaking via webcam from his home in Oakland, California. “That’s all from, say, a dozen 20 years ago.” He says there are about 100 scientific trials of ketogenic diets being conducted in the United States. “The research community has gotten fascinated by them because they’re so effective.”
Taubes has experienced this effectiveness. Around the time that he began researching his controversial article, he weighed 17st 3lbs, an increase of 2st 3lb from his weight as a young man. “I hadn’t had an avocado in a decade. I thought that, like red meat, it would kill me with heart disease or colon cancer the moment I bit into it.”
Intrigued by what was then the fringe science of low-carb, high-fat, he experimented with the Atkins diet. “I switched from this low-fat, mostly-plant diet on which I’d been getting fatter. I started eating eggs and bacon for breakfast, and lunch would be half a roast chicken or a steak with green vegetables.” Dinner would be similar. Taubes lost 11.3kg (almost two stone).
Today he is a lean and muscular 64-year-old. Taubes is a good advertisement for the keto diet, to which he remains faithful. He is still fighting the dogma that obesity is a consequence of individual weakness rather than a hormonal imbalance caused by the modern Western diet. Our bodies, the argument goes, evolved in an environment where fatty meats and fresh leaves were much easier to come by than the starchy, sugary foods we eat today.
Yet public health guidance typically recommends bread, pasta and potatoes. “Starchy food,” says the NHS’s Eatwell Guide, “should make up just over a third of the food we eat.” Guidance along those lines, Taubes says, “is just the wrong advice. It works for lean and healthy people, who, if they follow that advice, will probably remain lean and healthy. But for those of us who are predisposed to get fat, and we are now 50 per cent of the population, that’s the wrong advice. We do that diet and we get fatter, and/or we get hungry. So we’re either going to be fatter, and trying to restrict how much we want to eat all the time, because we’re constantly hungry, or we’re going to eat to satiety and really have a problem with our weight and our blood sugar.”
So why would the NHS and other public health authorities promulgate such a destructive diet? Advocates of low-carb, high-fat argue that this has happened for several reasons. The main one is that people of naturally healthy weights tend to assume that whatever they eat should work for others, too. So in a society in which most people are slim and grain-based diets are cheap and practical, grain-based diets are likely to appear favourable. Based on what was, in Taubes’ view, flimsy evidence, nutritionists such as the charismatic Ancel Keys argued from the 1950s onwards that saturated fat caused heart disease. Food manufacturers used cheap, high-carb products such as corn and wheat, using them to create processed foods that were marketed as low-fat but which exacerbated obesity rather than alleviating it.