Which diet is the best?
For many years, researchers have been desperately searching for dietary determinants of health within the populations of developed countries. Countless hours are spent poring over huge swathes of data, picking apart minute differences in the macronutrient breakdown of people’s diets. Time after time, percentages of fat, carbohydrate or protein are measured, but rarely are any strong associations with health and longevity found.
Despite billions spent on obesity related nutrition research over the past forty years, there have been precious few breakthroughs with the potential to impact on population health. When it comes to the effect that diet has on our long term wellbeing, there is so little that we know for certain, that it is almost embarrassing.
Although the devastating health harms of malnutrition are well understood, once we have sufficient calories and micronutrients, what else do we definitively know is good for us? Eat some vegetables. Get enough protein. A bit of fat, especially the essential ones. Some fibre. A few complex carbs. That’s about all anyone can agree on, and even then there are doubters.
But consider this for a moment. Perhaps it is inevitable that once a diverse human population has free access to food, some people will get fat. And in exactly the same environment, others will not. One thing that we definitely know is that our weight is determined largely by our genetics, not the macronutrient breakdown of our diet. This might seem like crazy talk, but it is backed by far more compelling evidence that the carbohydrate insulin hypothesis, the shaming of sugar, or the demonization of ‘Ultra Processing’. Body weight is one of the most heritable characteristics ever studied, in much the same ballpark as height.
With enough calories freely available, some people’s weight will be higher than what is considered the aesthetic or health ideal. Often those people will decide to diet. Those that choose not to will be shamed for their slothful laziness. And sadly, the majority of those that decide to restrict their way to thinness, will eventually fail to lose weight over the long term. This failure gives rise to a multi-billion-dollar diet industry, chocked full of deception and false promises, and intent on making larger people feel guilt and shame. In failing to become the thin people that society pressures them into being, failed dieters are cast as moral degenerates, incapable of a simple bit of willpower. But perhaps in reality, society is expecting them to become something that they are not.
No one will ever be able to perform a definitive experiment to prove which diet is the optimum for weight management or health, and there are too many people making money from their own brands of false dietary certainty for there ever to be a consensus. But while we argue, we should remember that we already know what really makes people sick. It is not people’s food choices that are most likely to cause early death. It is poverty, inequality, and broken lives. No dietary change can insulate people from these things. Perhaps the reason why we have not yet discovered which diet is best, is because within a society that has enough food, any diet that rich people eat is the one most associated with good health.
If you want one golden health tip, a transformative piece of advice that will guarantee to make you happier and healthier, then the assorted gurus of dietary health have no answers for you. The true answer is something that we already know. For a long life, don’t be poor. And if we really want to improve the health of the world, then it is inequality, not carbohydrates, that we need to address.
Anthony Warner liep 25 jaar geleden voor het eerst een professionele keuken binnen en verdiept zich sindsdien in de wereld van voeding en de bijbehorende industrie. Hij is de key note speaker tijdens het Food & Nutrition Evenement dat EVMI en C2W organiseren op 6 november. Zie pagina’s 18, 19 en 20 voor de andere sprekers en aanmeldmogelijkheden.