In a series of studies across five countries on three continents, research to be published in the journal Psychological Science, shows whether a person believes obesity is caused by overeating or by a lack of exercise can predict whether he or she will gain or lose weight.
With two-thirds of the adult US population classified as overweight or obese and similar numbers in many developed nations, obesity has become an important health concern, researchers say.
“The greater the extent to which you believe it is diet, the thinner you are on average,” says Brent McFerran, a marketing professor at the Ross School of Business at the University of Michigan.
People who believe obesity is caused by diet eat less food. Those who believe it is caused by a lack of exercise should work out more. The problem with that is that people tend to overestimate the amount of calories burned during exercise and underestimate calories in the food they eat.
For example, a 20-ounce venti Java Chip Frappucino from Starbucks contains 580 calories—and would take the average person four hours to walk off.
This is not to say that exercise doesn’t help reduce weight as long as calorie intake doesn’t also increase, says co-author Anirban Mukhopadhyay, a marketing professor at the Hong Kong University of Science and Technology.
“Our finding is simply that people who believe strongly in lack of exercise as the primary cause, rather than poor diet, tend to have higher body masses.”
Source: University of Michigan