SYDNEY: Are you obese? Well, blame it on your social nature, for a new study has found that outgoing and sociable people are more likely to be overweight, while anxious and worried types tend to be thin.

Masako Kakizaki of Tohoku University and colleagues questioned 30,000 people, aged between 40 and 64, in north-eastern Japan about their height and weight. The participants were also given a personality test.

The researchers found that extroverts had a greater chance than other people to have a body mass index (BMI) of more than 25, a commonly used definition of overweight.

After controlling for other factors, such as smoking, men in the most outgoing group were 1.73 times more likely to be obese than their most introvert counterparts.

Meanwhile, sociable women were 1.53 times as likely to be obese.

On the contrary, those who had the most anxious personalities were twice as likely as the least anxious to be underweight, or have a BMI of less than 18.5, the researchers said.

"These results may provide clues to devising more effective measures for preventing overweight, obesity or underweight," News.com.au quoted the researchers, as saying.