Speed of eating and 3-year BMI change: a nationwide prospective study of mid-age women

Objective: To conduct the first nationwide population survey to examine the associations between changes in speed of eating and weight gain over 3 years. The study also explored whether faster eating at baseline was related to healthy-weight women becoming overweight after 3 years. Design: Longitudinal. At baseline, participants were randomly selected from a nationally representative sampling frame to participate in a prospective study. Women completed self-administered baseline questionnaires on demographic and health measures. Self-reported speed of eating, smoking status, physical activity, menopause status, and height and weight were collected at baseline and again 3 years later. Setting: Nationwide study, New Zealand. Subjects: Women (n 1601) aged 40-50 years were recruited at baseline from New Zealand electoral rolls. Results: There was no evidence of associations between 3-year BMI adjusting for baseline BMI and either baseline speed of eating (slower and faster; P= 0.524) or change in speed of eating (consistently faster eating, consistently slower eating, slower eating at baseline but not at 3 years, faster eating at baseline but not at 3 years; P= 0.845). Of the 488 women with healthy BMI (18.5 to < 25.0 kg/m(2)) at baseline, seventy-seven (15.8 %) became overweight (BMI= 25.0 kg/m(2)) after 3 years. Compared with those who were slower eaters at baseline, faster eating at baseline did not increase the risk of becoming overweight 3 years later (P = 0.958) nor did change in speed of eating (P= 0.236). Conclusions: Results suggest that once women have reached mid-life, faster eating does not predict further weight gain.