Eating Quickly, Until Full Increases Risk of Overweight, Study Finds

Posted Oct 21, 2008.By Jonathan Gardner

People who eat quickly and until full are significantly more likely to be overweight than are those who do not exhibit those behaviors, according to a Japanese study published online Oct. 22 in BMJ.

The cross-sectional study of 3,287 people in two Japanese communities who self-reported that they ate fast or very fast and also ate until full were more than three times as likely as those who did not eat quickly or until full to have a body mass index greater than 25 kg/m² (multivariable adjusted odds ratio 3.13 for men, 3.21 for women) (BMJ 2008 Oct. 22 [doi:10.1136/bmj.a2002]).

Past research has suggested that fast eating is associated with overweight, but this research suggests that the two behaviors combined have an additive effect on the likelihood of being overweight, said Koutatsu Maruyama of the department of social and environmental medicine at Osaka (Japan) University, and associates. The researchers measured a relative excess risk of being overweight of 1.10 for men and 1.27 for women who ate quickly and until full.

In an accompanying editorial, Elizabeth Denney-Wilson of the Centre for Primary Health Care and Equity at the University of New South Wales, Sydney, and Karen Campbell of the Centre for Physical Activity and Nutrition Research at Deakin University, Melbourne, said the study suggests that the rising prevalence of obesity may be in part the result of eating behaviors that can be modified (BMJ 2008 Oct. 22 [doi:10.1136/bmj.a1926]).

"The study builds on evidence that eating behaviours are important in promoting positive energy balance (taking in more energy than is expended) and may contribute to the current epidemic of obesity. The drive to overconsume energy when it is available is probably an evolutionary imperative; however, until the last decade or so, most adults did not have the opportunity to take in enough energy to enable fat to be stored."

The researchers recruited analyzed data from 1,122 men with a mean age of 55 years and 2,165 women with a mean age of 52 years who took part in surveys on cardiovascular risk factors from 2003 to 2006 in Ikawa, a rural community, and Yao, a suburban community, both in Japan. Subjects reported whether they ate until full and whether they ate very fast, fast, medium, slow, or very slow.

Of the men, 50.9% (571) reported eating until full and 58.4% (1,265) of the women reported doing so, the researchers write. Those reporting eating either fast or very fast were 46.6% (523) men and 36.3% (785) women, according to the researchers.

The researchers acknowledged that they based their findings on self-reports, which may have introduced some bias. They added that there may be other confounding factors such as educational history and that the association between speed and satiety with body mass index does not prove causality.

However, they said that the large size of the sample and the population basis of their study suggest that the findings are valid.