Eating fast leads to obesity: Findings based on self-administered questionnaires among middle-aged Japanese men and women

Background: Few epidemiologic studies have examined the association between the rate of eating and obesity. In this study, we cross-sectionally examined the association of the self-reported rate of eating with current Body Mass Index (BMI), and BMI-change from 20 years of age to the current age. Methods: Subjects were 3737 male (mean age + standard deviation and mean BMI ± standard deviation: 48.2 ± 7.1 years and 23.3 ± 2.7 kg/m ²) and 1005 female (46.3 ± 7.0 years and 21.8 ± 2.8 kg/m ²) Japanese civil servants. We measured self-reported categorical rate of eating, current BMI, BMI at age 20, and BMI-change from age 20. Energy intake was assessed over a 1-month period with a brief-type diet history questionnaire. Results: The multiple regression analysis in which the current BMI was regressed by categorical rate of eating, energy intake, age, and lifestyle factors showed that current BMI steadily increased by -0.99, -0.67, 0.81, and 1.47 kg/m ² along with the progress of categorical rate of eating from the 'medium' group to 'very slow', 'relatively slow', 'relatively fast', and 'very fast' groups, respectively, in men. In women, the corresponding values were -1.06, -0.35, 0.50, and 1.34 kg/ m ². When the BMI increment from age 20 to current age was regressed in the same manner, the increment was -0.63, -0.34, 0.57, and 1.05 kg/m ² in men and -0.71, -0.32, 0.34, and 1.14 kg/m ² in women, respectively. Additionally, both BMI at age 20 and current height were positively associated with rate of eating. Conclusions: Our results among middle-aged men and women suggest that eating fast would lead to obesity.