Fatty and Skinny went to the beach...

The ABC is reporting a study on thigh circumference and its relation to heart disease. The gist of the conclusion is this (from the ABC article):

The research, published in today's edition of the British Medical Journal, reveals that thigh circumference is linked to the risk of heart disease and premature death.

The study looked at more than 2,800 men and women with an average age of around 50.

It found that the risk of heart disease more than doubled for both men and women who had a thigh circumference of less than 55 centimetres.

Those participants with thighs between 55 and 60 centimetres received a protective effect against heart disease, the study reports.

But that protective effect reduced for people with thighs above 60 centimetres in circumference.

I read that and thought, "Yeah, clearly everyone understands exactly how weight and disease are related." Then I wandered over to Feministe and read this post about the Pro-food movement and its lack of skepticism with respect to the "obesity epidemic", and so I started wondering again about cause and effect.

If you think that measuring thighs and concluding anything about future health prospects is silly, you'd be right. It's about as silly as measuring BMI and concluding anything useful about future health prospects. The problem here is that for a very long time, people have been measuring convenient things, and then correlating them with actual health outcomes. That'd be fine if they then spent lots of time trying to work out what those convenient measures were actually proxies for. Obesity correlates well with lots of stuff. The number of storks in Hamburg also correlates really well with the number of babies born.

Still, I very much doubt that there would be too many people arguing that terrible diet and no exercise is a good option. If you read Shapely Prose, the main message is that your weight doesn't matter because there is no demonstrated way to reduce it in the long term anyway. And the vast majority of studies focus on weight, not lifestyle, in predicting health outcomes.

It is not surprising that you find that fat correlates with health problems, there is a correlation between bad eating and insufficient activity and fat. I'd even go so far as to say that far less people would be fat if everyone ate well, exercised regularly and never, ever dieted for their entire lives. However, once you get fat, all the evidence suggests that trying to get thin again is probably pointless, and more importantly, if you fail, worse for you than being fat in the first place. Don't get me wrong, this hasn't stopped me wishing I could just lose 5kg...

Still, the problem here, from a health point of view, is that by obsessing about the weight, we are ignoring the health. The fundamental argument between the two sides of this debate is whether, given that someone follows a good diet and exercise, they will lose weight and keep it off. Kate Harding and others would tell you the answer is an unequivocal "No". Others (and not just the diet industry) will say "Yes". But ultimately, who gives a shit? If the focus is health, and most people are agreed that good diet and exercise are the better predictors of health, why do we discuss weight at all? If the "No" camp are right, focussing on weight completely defeats the purpose. If a healthy lifestyle doesn't result in weight loss, and weight loss is the only thing that is valued, why bother with the healthy lifestyle? Hands up if you or someone you know has or does say "Fuck it, I'm fat when I eat well, and I'm fat when I don't, may as well eat whatever the hell I want." Under those conditions, you will see an excellent correlation between BMI and bad health.

If the "yes" camp are right, taking the body image issues out of the equation and encouraging people to be healthy irrespective of their weight will result in weight loss anyway. And if they are right, why do they care about weight? It's just one of the side effects of unhealthy living. Surely we want to be thin because it's healthy, not healthy because it will make us thin? So focus on the healthy and forget about the weight.

My personal anecdata is that on the CSIRO diet, I feel better. Sometimes I lose weight, sometimes I don't. Sometimes I put it on. But following a menu plan is good for me, I can feel it. It results in a much broader range of food in my diet, and apparently I do have a body that prefers it when I don't eat carbs at night. When I am eating badly and not exercising, I feel crappy. But I can't find a correlation between well-being and weight, personally. I'm not saying others can't, just that at least one person doesn't*.

The only really positive thing I took out of this report about thighs, is that the authors focussed on the fact that muscle mass was the most important thing - in other words being fit is important, and more so than the amount of fat sitting over the muscle. They did imply that more fat reduces the bonus from muscle, but lack of muscle was clearly the big risk indicator. It's still just another dodgy proxy indicator, and I won't be measuring my thighs to calculate my risk, but pointing out that lifestyle is what matters, not measurements is definitely a Good Thing.

*I have lost lots of weight deliberately, and kept it off for more than 5 years, but it was crazy making getting there, and I'm fairly convinced that living on a salad roll whilst riding a bike 10km each day is not good for me.