Why Diets Don’t Work (or How to Stop Judging Obese People)

The Obesity Epidemic

Obesity has doubled since the seventies. The ruling hypothesis to explain this is that the rise is due to more calories consumed and less exercise performed.

But, according to food consumption statistics, our diet has ‘improved’. We eat less fat and saturated fat now than we did in the seventies. And we do more exercise now as well. Believe it or not, exercise was seen as potentially unhealthy in the 1960s. The only things that we are eating more of now compared to the seventies and earlier are carbohydrates.

Furthermore, obesity is linked to poverty, not to the excess food that comes from wealth. In very poor families, the men are very fat – and the women are even fatter, even though they do most of the work. Why would it be linked to poverty? The mass production and distribution of carbohydrates like rice, sugar and wheat means that these are cheap food products compared to the relatively expensive meat, cheese, fruit and vegetables. There is no ‘thrifty gene’ that tells our bodies to store fat when times are good or when we know that food will be scarce.

The storage of fat is an evolutionary adaptation, not a response to environmental circumstances. For example, squirrels will put fat on in winter, whatever you do. You can keep them from hibernating, you can starve them, you can even perform surgery to remove their winter fat – but their bodies will still put the weight on, and lose it again in the spring. That’s just what happens: it’s nothing to do with their diet and nothing to do with the reduction in exercise during hibernation.

It’s Nothing To Do With Diet or Exercise

(Of course, diet and exercise are vitally important in many other aspects of health. I am talking here purely about obesity.)

Starvation diets don’t work. You lose a bit, then put it back on with interest when you go off the diet. (This has nothing to do with the health benefits of eating slightly less than you want, see my earlier post.) Often the obese eat less than the lean. Gluttony and sloth are not to blame, they are just ways of making fat people feel guilty and of making thin people feel good about their superior morals.

Positive and negative caloric balance, eating more or less than you need, does not affect weight. Our body finds balance no matter what we do. If we eat more than we need, our metabolism will speed up and burn the excess calories off. If we eat less than we need, our metabolism will slow down and conserve calories (and we might live longer…).

Forced over-eating

There was an experiment where volunteers were fed 4000 calories a day. The subjects gained a few pounds and then their weight stabilised, so the researchers decided to increase the calories:

  • First to 5000 calories a day.
  • Then to 7000 calories a day.
  • Then to 10000 calories a day – all while remaining sedentary!

The researchers noted that there were, ‘marked differences between individuals in ability to gain weight.’ One person gained just 9lbs after 30 weeks of this regimen. Afterwards, everyone lost weight with the speed that they had gained it.

Calorific balance tends to 0, whether you are on a 1000 calorie diet or a 10000 calorie diet.

Exercise

Nor does exercise affect weight. If we exercise more, we eat more. Hence the phrase, ‘work up an appetite’. Exercise only burns a fraction of the calories we consume. You would have to walk up 20 flights of stairs to burn off the caloric input of 4 pieces of bread.

Danish researchers trained previously sedentary people to run marathons. After 18 months of intensive training:

  • The 18 men lost an average of 5lbs (2.25kg) of fat.
  • The 9 females lost nothing at all.

There are even studies that show people getting fatter with exercise, just as dieting regimes can do.

Genetics

Weight gain varies ten-fold between different people, indicating that it is genetic. This shouldn’t come as a surprise to us: we breed cattle for high fat yield using genetic principles. The difference in the size of cows is not put down to over-eating or sedentary behaviour, so why do we do that for fat humans?

We are born with a genetically influenced body shape. The proportion of fat on your body will not change even if you lose or gain weight. There are three basic types of body morphology:

  • Mesomorphs: wedge-shaped power houses.
  • Ectomorphs: thin as a rake.
  • Endomorphs: pear shaped.
Of course, most people have elements of one and aspects of another, but the general principle is clear: your shape is genetically influenced.

Size is a Class Issue

There is also a class issue here. McDonald’s is blamed, but Starbucks is not, even though a large frappacino with cream has just as many calories as a Big Mac. People who watch TV are called couch potatoes and lazy, but people who stay sitting at their desk reading books are not.

Finally: if our environment was toxic, then why aren’t we all fat? It is not down to will-power or moral rectitude, as some people would like.


This article is based on the information found in The Diet Delusion by Gary Taubes (p233 onwards)

What do you think?