Quicker pace of eating associated with higher body mass index

A new study published on bmj.com finds that people who eat quickly and eat until full are three times as likely to be overweight than people who do not share those eating behaviours.

The obesity epidemic gripping the industrialised world is partially the result of eating behaviours that have drastically changed in the last few decades. With the wide availability of inexpensive food in larger portions and fast food, and the increased frequency of eating while distracted (by TV, for example), adults are now able to consume enough energy that their bodies are storing significant amounts of fat.

Professor Hiroyasu Iso (Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Japan) and colleagues studied 1,122 Japanese men and 2,165 Japanese women who were between the ages of 30 and 69 in 2003 and 2006. The researchers studied the association among the pace of eating, eating until full, and being overweight by analysing data collected from diet history questionnaires filled out by the participants.

The survey results showed that 50.9% of men and 58.4% of women ate until they were full; 45.6% and 35%, respectively, indicated that they ate quickly. Those participants who claimed to both eat until full and eat quickly had a higher total energy intake and higher body mass index (BMI) than those participants who did not share those behaviours. In fact, both men and women in the "eat until full and quickly" group were about three times as likely to be considered overweight that the same comparison group.

"The combination of the two eating behaviours had a supra-additive effect (additive interaction) on being overweight," conclude the authors. "As it is difficult to estimate these causal effects in a cross sectional study, prospective cohort and intervention studies will be needed to validate these associations between eating behaviour patterns and being overweight."

Elizabeth Denney-Wilson (University of New South Wales, Australia) and Karen Campbell (Deakin University, Australia) write in an accompanying editorial that the findings of Iso and colleagues emphasise the impact of current eating patterns on the current obesity epidemic.

"Clinicians should recognise that behavioural counselling, using cognitive therapy, can help in the management of this aggressively 'eat more' food environment. Evidence suggests that adults can successfully modify their speed of eating and in turn their energy intake. Furthermore, adults are likely to be responsive to monitoring feedback regarding feelings of fullness. Helping patients to increase their daily physical activity will further reduce energy imbalance," conclude Denney-Wilson and Campbell.

(Source: bmj.com: Osaka University: October 2008)