Changes in eating behaviors and body weight in Koreans: The Healthy Twin Study

Objective: We examined the associations between eating behavior at baseline and changes in eating behaviors with weight change, and quantified the contribution of eating behavior and genetic effects on weight change. Methods: A prospective study of male (n = 482) and female (n = 879) Korean twins and family members who were weighed and assessed twice (baseline visit from December 2005 to December 2008, follow-up visit 2.7 ± 0.9 y later) using eating behavior subscales (external, emotional, and restrained eating) as measured by the Dutch Eating Behavior Questionnaire. Results: After adjusting for family variables, eating behavior subscales at baseline, changes in emotional and restrained eating, age, education, weight, and lifestyle at baseline, and menopausal status at baseline (for women), an increase in external eating was significantly associated with weight gain in men (1.08, 95% confidence interval 0.41-1.74) and in women (0.63, 95% confidence interval 0.13-1.12). None of the three eating behavior subscales at baseline or changes in emotional and restrained eating were associated with weight change. Eating behavior at baseline and changes in those eating behaviors accounted for 4% and 1% of the changes in weight in men and women, respectively. Additive genetic effects in women contributed to 18% of weight change, whereas in men there was no genetic contribution. Conclusions: These results suggest that an increase in external eating may predict adult weight gain in men and women. However, the relative contribution of eating behavior to weight change was very small, whereas the contribution of genetic effects on weight change was significant in women.