People's views about what causes obesity may influence both their eating habits and their weight, new research shows.
The finding suggests that public health campaigns may need to factor that into the equation to be effective, the study authors noted.
To examine the issue, the researchers conducted a series of surveys across five countries on three continents. Published recently in the journal Psychological Science, the study found people in Korea, the United States and France all held similar beliefs that either poor diet or lack of exercise was the leading cause of obesity.
And those who linked obesity to unhealthy eating habits had lower body mass indexes (BMIs) than those who blamed lack of physical activity. BMI is a measurement of body fat based on height and weight.
Genetics largely ignored
"There was a clear demarcation," study author Brent McFerran, of the Ross School of Business at the University of Michigan, said in a news release from the Association for Psychological Science. "Some people overwhelmingly implicated poor diet, and a roughly equal number implicated lack of exercise. Genetics, to our surprise, was a far distant third."
However, "what surprised me the most was the fact that we found lay theories to have an effect on BMI over and above other known factors, such as socioeconomic status, age, education, various medical conditions and sleep habits", McFerran pointed out.
The study authors noted that the link between views on obesity and exercise may also be associated with how much people eat. They found Canadian participants who felt obesity was the result of physical inactivity ate many more chocolates than those who saw diet as the main culprit. Meanwhile, people in Hong Kong who stressed the importance of exercise also ate more chocolate than those who saw diet as the main cause of obesity.
The researchers concluded that people's beliefs about obesity play a role in eating habits and BMI.
Anirban Mukhopadhyay, of Hong Kong University of Science and Technology, concluded in the news release that this is "the first research that has drawn a link between people's beliefs and the obesity crisis, which is growing as fast as people's waistlines".
Studies show that two-thirds of U.S. adults are overweight or obese. Obesity is also a growing problem in many developed nations.
The U.S. National Library of Medicine provides more information on obesity.