Brittany Farb from Northwestern University reports on a recent weight loss study.
In a new study, researchers at Oregon Health & Science University in Portland, calorie restriction is not an effective weight-loss strategy. A study published in the April edition of American Journal of Physiology – Regulatory, Integrative and Comparative Physiology found that decreasing calories greatly decreased the amount of activity expended. The scientists were surprised by this drop.
They probably shouldn’t have been surprised. Take a look at generations of dieters, and you will find the same thing. They don’t like to exercise. Why? They don’t have a lot of energy.
Now, the study was actually an animal study, but despite that it provides some helpful information.
The researchers placed 18 female rhesus monkeys on a high-fat diet for several years before returning to a lower-fat diet with a 30 percent reduction of calories. For one month, the monkeys’ weight and activity levels were closely monitored and compared to three monkeys that were fed a normal diet and exercised an hour a day. This comparison group did lose weight.
This is a bit of mistake in research design. They’ve changed two variables. They lowered the calories, and they changed the diet to a lower-fat diet.
So it’s not entirely clear that it is the calorie restriction that is causing the problem. It’s possible that decreasing the amount of fat caused a decrease in the metabolic rate as well.
Still, it gives some further evidence that dieting alone may not be the way to permanent weight loss.
http://news.medill.northwestern.edu/chicago/news.aspx?id=163719
