Faster self-reported speed of eating is related to higher body mass index in a nationwide survey of middle-aged women.

This study is the first nationwide population survey to explore the association between speed of eating and degree of obesity. The objective was to cross-sectionally examine the relationship between self-reported speed of eating and body mass index (BMI; calculated as kg/m(2)) in a nationally representative sample of New Zealand women. In May 2009, a sample of 2,500 New Zealand women aged 40 to 50 years was randomly selected from the nationwide electoral rolls. A 66% participation rate was achieved. Potential participants were mailed a self-administered questionnaire containing questions on self-reported speed of eating, demographics, health conditions, menopause status, physical activity, height, and weight. Univariate models were used to examine the associations between demographic, health and behavioral variables, and BMI, while a multivariate model was developed to investigate the relationship between self-reported speed of eating and BMI. After adjusting for age, smoking status, menopause status, thyroid condition, ethnicity, socioeconomic status, and physical activity, BMI statistically significantly increased by 2.8% (95% confidence interval: 1.5% to 4.1%; P<0.001) for each category increase in self-reported speed of eating. Although the direction of causality requires confirmation in longitudinal and randomized intervention studies, the results suggest that faster eating is associated with higher BMI in middle-aged women.