Same Old Story
Friday, March 26, 2021
My opinions on obesity put me at odds with the majority of people writing about food and health. Readers might be surprised to learn that this bothers me a great deal. If you have read this blog and my books over the years, you will know that I don’t care that much about being popular and have never shied away from a controversial opinion or three. But I do care that, in my opinion, almost all political and journalistic rhetoric surrounding obesity is based on a set of dangerous false assumptions. By extension, because public health policy is largely reactive popularism these days, all Government led obesity initiatives are destined to fail.
From neoliberal calls for more personal responsibility, libertarian paternalists’ suggestions that we just need to rearrange the cafeteria shelves, or the left’s claims that we must immediately reign in the power of giant corporations, everyone is getting obesity wrong. As a result, huge numbers of people are being done irreparable harm. I believe this to be the scandal of our age, the thing that we will look back on in horror in fifty years’ time and wonder how we could have been so foolish. And so cruel.
Things are not improving and are likely to get worse as public health bodies adjust to a post pandemic world and get back to what they love the most – blaming fat people for all our problems. Although the rhetoric in a recent talk by the UK’s Chief Medical Officer Chris Whitty was vastly more compassionate and informed than anything fat-shamer-in-chief Sally Davies ever mustered, it was still full of the same tired policy options that have failed to work in the past.
I have come to accept that most people will disagree with me on this. In my second book, I outlined what a complex, confounding problem obesity is and why those selling simple solutions are, without exception, hawkers of snake oil. I stand by this assessment, but I have to confess that my opinions on the causes of obesity have crystalised somewhat over the intervening few years. My thoughts regarding what we should do however, haven’t changed a bit. I now think that obesity is a simple issue. But I still believe that trying to solve it is a fool’s errand.
To fully explain my position, it is necessary to unpack three underlying assumptions that drive most of the rhetoric on obesity. Until we can do this, we will be permanently stuck making the same set of flawed assumptions and producing the same lists of pointless, ineffective interventions. This is not only a waste of time and resources, it is actively harming huge numbers of people.
Assumption Number One - There is a correct weight to be.
If we are going to classify people as over-weight or obese, then we are automatically assuming that there must be a correct weight that humans should be. Or at least a correct BMI. But why do we think that a BMI between 18 and 25 is ideal? At almost all stages of life, it is not the optimum for health or longevity. 18 is dangerously low for many people, especially the elderly. And as we age, even staying within the 20-25 range is associated with reduced life expectancy.
The 20-25 range is based on a set of assumptions drawn from 1950s insurance industry data, although the lower limit was subsequently altered downwards to account for differences between ethnicities. It helped that this range correlated with a certain aesthetic of the time, cemented during the 1960s, as ultra-lean, athletic bodies began to be considered ideal in Western culture.
The divisions are entirely arbitrary, sitting at 25 for overweight and 30 for obese only because they are nice round numbers. Yet every single obesity policy hangs its hat on these finger-in-the-air limits, assuming that they represent some essential human truth about how we should be. Any deviation is considered an unnatural state, something that should be rectified immediately, whatever the cost.
We never stop to question why this should be the case. We never consider how ridiculous it is that anyone who does not fit within these narrow bounds is deemed abnormal. Perhaps we believe that our culturally defined notions of what we find attractive are innate, and that we are somehow in touch with our caveman ancestors when we are checking out some model or movie star. Or maybe we have seen footage of a few hunter gatherer tribes looking skinny and believe that they are representative of our deep past (spoiler alert, they aren’t). There is no single BMI that it is natural or ideal for all humans, but the idea that there should be is baked into almost every article, policy idea and newspaper column on obesity. It is so integral to the notion of an obesity epidemic, that we don’t even think about it anymore.
So, if only for the time it takes to read this blog post, I ask you to unpack that belief. Set it aside, no matter what the diet industry, newspaper columnists and the public health authorities tell you. There is no correct BMI. It is not a failing for someone to fall outside of these arbitrary guidelines.
Assumption Number Two – It’s your own stupid fault.
Although many people will find Assumption One difficult to grasp, Number Two is the really hard one. This is the point where most people’s thinking departs from mine, but here we go -
The amount of fat someone’s body stores has nothing to do with their willpower, weakness or morality. BMI is, to an incredibly large extent, a result of genetics. It is one of the most heritable characteristics ever studied, in the same ballpark as height. Our bodies have a set point weight, defined by our genes and controlled by our hormones. You can temporarily change your weight, as many people do through dieting, illness or starvation. But if food is available, your body will eventually bring you back to its desired weight, no matter what you do.
Dieting is much like holding your breath. Just like breathing, eating is entirely voluntary, right up until it isn’t. We can all hold our breath successfully for a while, but eventually, if air is available, you will breathe. Your cells will signal to your brain that oxygen is required, and breathing will eventually be taken out of the hands of your conscious self. This is true however much willpower you have.
Our desire to eat is controlled by the same primal part of the brain, it just operates over much longer timescales. This provides a compelling illusion of free will when it comes to food intake. If you restrict food for a few weeks, you will lose some body fat. People will probably tell you that you look great, but your fat cells will assume that you are starving. Those cells will tell your brain that it is time to eat, and the longer you go without food, the louder that call will become. Remember that your body wants you to be a certain weight, defined by your genes, and will do anything it can to get you there. It will punish you, both physically and mentally, should you choose to fight it. Eventually, as with breathing, if food is available, you will eat.
When someone is heavier than you, it’s not because they are weaker, stupider, or less able to resist temptation. It’s not because they are more susceptible to advertising or can’t resist 2 for 1 offers on crisps. It’s not because they don’t understand what Ultra Processed Foods are, that they don’t shop in farmer’s markets, or that they’ve never seen a heritage carrot. It’s not because of sugar, carbs, fat or protein. It’s not even because they are poorer than you, or less able to cope with the world. It is simply because their genes dictate that they are heavier. You have no reason to feel superior. You should not even feel sympathy. They are a naturally different BMI, just like other people are taller, have finer hair, larger feet, or different coloured skin.
Assumption Number Three – The 1980s.
But, but, but, I hear people cry. Genetics haven’t changed. Evolution is slow, growth in obesity is fast. How come we have all gotten so much fatter since the 1980s. That can’t be because of genes. Something bad must have happened. Big food. Big sugar. Carb madness. Guidelines. Blah, blah.
This is not quite the own that many people seem to think it is. Believe it or not, for a humble chef, I understand a little bit about genetics. I am aware that the genotype of humans has not changed much in the past couple of generations, and certainly not enough to produce a measurable difference in rates of obesity.
But what almost everyone fails to recognise, is that BMI did not shoot up dramatically at the end of the twentieth century. Any suggestion that it did is simply a statistical slight of hand. The number of people passing the arbitrary BMI threshold for obesity did increase in the early 1980s in the UK and US, but this is consistent with average BMI increasing steadily since the late 1800s (and yes, I understand that is still not enough time for genetic changes to play a part).
Obsessively focusing on the percentage of people who are obese, is a bit like trying to study changes in height by only considering how many people are taller than Michael Jordan. Or assessing general educational performance by counting how many geniuses there are. It might tell us something, but it is an odd way to measure the world. Averages are far more powerful if we want to look at trends over time, so it is curious that when it comes to BMI, averages are almost never considered.
Perhaps this is because averages don’t make for such an exciting or dramatic story. Average BMI has risen slowly and consistently over the past one hundred and fifty years, as the global food supply has become increasingly secure and plentiful. Compared to 1960, we now produce 50% more food per capita, despite the global population more than doubling. As a result, far fewer people now go hungry. In the developed world, severe hunger is all but abolished, but for much of the 20th Century, this was far from the case.
Rich people have always been overweight and obese, in much the same proportions as most of the population in developed economies are today. Now, even relatively poor people in countries such as ours usually have enough calories to eat. We finally have the world we have always desired, one where genuine hunger is rare and shocking. Sixty years ago, lots of poor people were regularly going hungry, even in the world’s richest nations. But now, with our plentiful food supply, we are seeing most people reach their genetically determined weight.
Many people find this troubling, largely because Assumption One has convinced them that this is not the natural state of humanity. But it also feels as if there is snobbery at play. The rich were once lauded for their fatness, corpulent leaders of the world, scoffing rich banquettes and paying the proles to loosen their belt buckles. But now that everyone has enough food, and the poor get fat in equal numbers, they are derided as shameless spongers, destroying the economy and bringing the health service to its knees.
What to do?
In short, when food supplies are low, everyone stays hungry, and no one gets fat. But when food is plentiful, some people get fat and others don’t. Whether they do or not is largely determined by their genetics. The real reason for the obesity ‘epidemic’ is that we have almost banished hunger in many of the world’s nations. We are seeing what a human population looks like when everyone has enough to eat. In that world, people are different shapes and sizes. The fact that this is seen as a crisis, is only because of assumptions 1 and 2.
It is true that BMI is not 100% heritable. Some individuals will confound their genes and gain excess weight, for instance those suffering from the sort of eating disorders that result in overeating. Depression and other psychological problems may cause some to find comfort in food to a point where it overrides their hormones and instincts. And at the other extreme, some will live in a punishing world of constant hunger, or lose weight through illness and addiction.
But if left to our own devices, most of us will achieve a genetically determined BMI and stay there, perhaps increasing slightly each year as we age. If you are lucky, that BMI will be one that society deems acceptable. If not, you will face a lifetime of prejudice. Right now, that prejudice is accepted and endorsed by most governments, health care professionals and public health bodies.
If you unpack and move past these three assumptions, especially the first two, everything falls into place. Confounding questions about obesity finally have sensible answers. The reason why interventions never work becomes clear. Our obsession with researching different diets and strategies to 'solve' obesity, looks as ridiculous as it is ineffective.
Consider how easy it is to answer the following questions once these assumptions are stripped away -
Q. Why do countries with similar economies and similar diets have different rates of obesity?
A. Because different ethnic groups and populations have different genetic susceptibilities to weight gain.
Q. Why is there very little correlation between an individual’s diet and their BMI?
A. Because the composition of someone’s diet makes very little difference to their weight. When food is freely available, BMI is largely defined by your genes.
Q. Why does obesity always follow prosperity?
A. Because when fewer people go hungry, more people reach their genetically determined weight.
Q. How come most people will temporarily lose weight when they diet?
A. Because whenever you starve yourself, you lose a bit of weight. Eventually, as the diet industry well knows, the vast majority of people will put that weight back on. Some people can hold their breath for longer than others, but everyone has to breathe eventually.
Q. Why do some strong, confident, high achieving people seem to lack willpower when it comes to weight?
A. Because BMI has nothing to do with willpower. If you are always on a diet, you will always be hungry. Anyone living in a world of constant hunger is unlikely to achieve very much.
Q. Why don’t weight loss diets work over the long term?
A. Because your body wants to be a certain weight, and that is probably different to the weight society wants it to be. You are fighting your biology and your biology will win. Eventually, you will breathe. The longer you hold on for, the deeper that breath will be.
Q. If it doesn't work, why is the diet industry so lucrative?
A. Because our ability to temporarily restrict food gives us an illusion of free will when it comes to weight. This means that when diets fail, we are conditioned to blame ourselves, unaware that the product being sold is completely ineffective.
Q. Why do people living in the same environment have a range of BMIs?
A. Because throughout our evolution, we have been subject to a number of evolutionary pressures. In some environments, for instance on an open plain with lots of human eating predators, being fast and lean was probably an advantage. In others, for instance on an island with irregular food supply, being able to store lots of calories in times of plenty would have been favoured. The diversity of body sizes when food is freely available reflects this evolutionary history.
Q. Why does dieting often result in higher body weights over the long term?
A. Because if you are in a cycle of dieting and weight gain, your body will think the food supply is unstable. It is likely to prioritise storing calories in times of plenty, leading to a higher BMI. This is a natural adaptation to the world we evolved in.
Q. Why do public health interventions for obesity invariably fail?
A. Because, quite rightly, they do not place people into permanent food shortage.
Ask any question about obesity with these assumptions stripped away, and the answers fall out quite simply. I defy anyone reading to pose a question that doesn't just answer itself. That does not constitute proof, but combined with the past thirty years of supporting research into the genetic and hormonal causes of obesity, there is certainly a compelling case for a rethink.
If I am correct in my assumptions, can this knowledge actually make a difference? Personally, I think it can. But if BMI is not within our control, then any measures to reduce it at a population level are almost certainly inhumane. Unless we are willing to forcibly starve people, we pretty much have to give up on promoting weight loss.
Unfortunately, most people consider this conclusion so earth shatteringly problematic, that it is unlikely to ever take hold. We would prefer to be stuck in a pointless cycle of restrictive diets, dishonest weight loss claims, curtailing of freedoms and admonishment of fat people. The political right tell us that fat people lack willpower. The left, believing that they are more compassionate, tell us that ‘people of increased fatness’ are stupid and weak, unable to resist the lure of advertising and BOGOFs. Neither are correct. Both do great harm. The rhetoric of blame comes in from both sides.
It is a weirdly controversial thing to say, but I think that public health interventions should be about improving health, not changing appearance. We should focus on the nutritional quality of people’s diet, rather than its ability to cause weight loss. We should encourage exercise, smoking cessation, better quality food and social contact, not because these things will help shed pounds, but because they will help prevent disease. We should provide better mental health services, offer physical therapy, clamp down on abuse and prejudice. We should try to sever the links between body weight and disease, rather than constantly demand thinness from people who aren’t built that way. We need to stop fighting a war with people’s bodies and start helping bodies to thrive. The whole idea of an obesity epidemic needs to come to an end.
Whenever we judge success on how much weight people lose, we always fail. But if we start judging success on whether or not we are actually making lives better, we might just move forward. Over the past 50 years, the healthy life expectancy of overweight and obese people has improved dramatically. It should be a triumph that medical science has found ways of enabling fat people to live longer, healthier lives. But it is kept hidden as an embarrassing secret. We probably need to ask ourselves why this is the case.
For every negative health outcome associated with obesity, there are a number of tried and tested preventative measures or treatments that don’t involve losing weight. So maybe we should just focus on them. Maybe we shouldn’t weigh anyone at all. And although there will probably still be negative social implications of being fat, these only exist because the rest of us are being dicks. Perhaps we could all just try and be a little kinder.
This is hard for a lot of people, presumably because they don’t like looking at fat folk, especially the poor ones. It will never be a popular opinion. But just imagine that instead of all the ineffective policies that have been implemented over the years, the stigma inducing campaigns, the regressive taxes, the demonisation of foods, and the accusations that fat people are bringing the NHS to its knees, we had just tried to be a little bit more compassionate. Imagine if all the time we spent telling people to be thin, we had instead focused on improving their lives. Even if it hadn’t worked, we would almost certainly be living in a kinder, healthier world.
As our Governments and public health bodies attempt to deflect blame away from their significant failings over the past 12 months, fat people are going to increasingly be in the firing line. Much like they have been blamed for our crumbling, underfunded health service, they are now being held responsible for our Covid toll. This is completely unjustified, both statistically and morally. But unless we can unpack our assumptions about why some people gain weight, it will never cease.
For those who might complain that this blog post lacks references, please refer to my second book 'The Truth About Fat',which has hundreds of them and addresses all the points raised in this post in more detail. My third book, Ending Hunger,also covers several of the points raised, so buy that too. Stop being tight and don't expect me to do your homework for you in a free blog post.
