Researchers say people who devour meals too quickly are more likely to become overweight. (Jim Witmer/Dayton Daily News/Associated Press)

People who devour their meals quickly and eat until full are three times more likely to become overweight, a Japanese study on eating habits suggests.

The findings suggest it is not only the widespread availability of large portions of calorie-rich foods that contributes to the obesity epidemic.

Hiroyasu Iso and colleagues at Osaka University reported that men and women who said they ate quickly and until full were three times more likely to be overweight than those who had neither eating behaviour.

Specifically, the odds of being overweight were 3.13 times higher for men and 3.21 times higher for women among those who ate quickly and until full.

In the study, researchers asked more than 3,000 men and women aged 30 to 69 to fill in diet questionnaires that included questions about speed of eating and eating until full.

Half of the men and 58 per cent of women said they ate until they were full, and 45 per cent of men and 36 per cent of women said they ate quickly.

Those in the ate "until full and ate quickly" group also showed a higher body mass index and higher intake of calories, which supported the validity of the questionnaire, the researchers said.

"In conclusion, eating until full and eating quickly were associated with being overweight in Japanese men and women, and the combination of the two eating behaviours may have a substantial impact on being overweight."

Cause and effect not established

But a cause-and-effect relationship between eating behaviour patterns and being overweight can't be determined from a cross-sectional study like this one, the team noted in calling for more research to explore the link.

The researchers adjusted for age, smoking, being a desk worker and engaging in regular physical activity.

"It may be that the changing sociology of food consumption, with fewer families eating together, more people eating while distracted (for example, while watching television), and people eating 'fast food' while on the go all promote eating quickly," Elizabeth Denney-Wilson from University of New South Wales in Sydney and Karen Campbell from Deakin University in Victoria, Australia wrote in an editorial accompanying the study.

They called on doctors to work with parents to encourage healthy eating habits in children such as eating slowly, serving appropriate portions and eating as a family in a non-distracting environment.