Law For Food: The law affects what you eat. What you buy to eat affects the law.

Obesity and Activity
19 June 2008, 3:54 pm
Filed under: Food and Health

Via Marion Nestle, we have news of a study which suggests that the lack of physical activity is not the cause of increasing obesity in Europe. From the abstract:

As physical activity expenditure has not declined over the same period that obesity rates have increased dramatically, and daily energy expenditure of modern man is in line with energy expenditure in wild mammals, it is unlikely that decreased expenditure has fuelled the obesity epidemic.

If this is the case, then it seems highly likely that the increased obesity rate in the population is due to overconsumption of food. Note that the study does not suggest that energy expenditure is unconnected to obesity, but rather that energy expenditure has remained constant during a period in which obesity increased in the population.


2 Comments so far
Leave a comment

I see a lot of problems with this study. The methods used to measure daily activity were Double-labeled water, which shows resting or basal metabolic rate. This is a poor indicator of calorie-burning activities;

“while aerobic exercise is beneficial for cardiovascular reasons as well as direct calorie burning, the above studies indicate it is not useful for increasing resting metabolism.”
- (includes sources to studies)

Also, the study *starts* at 1980, probably the height of sedentary lifestyle in north america and europe. It is not really a shock to me to learn we are not much more active than in 1980. In any case, this study does not accurately measure physical activity, but rather BMR. They then, with no proof of relation, falsely equate BMR with physical activity. They thus fail to 1- study the relation between physical activity and obesity, and 2- demonstrate that physical activity is meaningless as a preventive or corrective behavior for obesity.

Comment by Nicolas

There’s no way I’m paying 32 dollars for the full text, but I think I agree that a reduction of energy is not the cause of the rise in obesity, whatever the methodology.

A more likely cause is diet and the macronutrient make up of people’s diets. More carbohydrate and artificial sweeteners means more insulin and more hunger. Gary Taubes has an interesting take when he says that exercise alone is poor at causing weight loss.

We might not be more active than in 1980, but Americans sure are fatter. And anecdotally, the same seems to apply whenever I go to Europe.

I doubt the truth of the caloric balance hypothesis anyway, since people have never, until the 20th Century counted calories, but are only overweight on such a grand scale in the western world. It might be that the independent variable lies outside of the caloric balance hypothesis.

Comment by Nick

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: