Influence of Behavioral and Environmental Factors on the Development of Obesity in Three-year-old Children -A Case-Control Study Based on Toyama Study-.

Obesity in children seems to be a risk factor for chronic diseases in adulthood. From the viewpoint of preventive medicine, factors influencing the development of obese children should be removed early in life.The purpose of this study was to the elucidate relationship between obesity in 3-year-old children and both behavioral and environmental factors by conducting a case-control study. Subjects were selected from the Toyama study. Matched-pair comparisons were performed between obese children whose Kaup's index was 18 or more (N=117) and control children (N=234) . Multivariate stepwised logistic regression analysis also applied to assess influence of confounding factors.The results indicated that the following 6 factors significantly influenced the development of obese 3-year-old children in exact Fisher's method analysis (p<0.05): person other than the mother responsible for taking care of the child, short sleep duration (9 hours or less), physical inactivity, eating snacks irregularly, overweight father (BMI≥24), and overweight mother (BMI≥24). For both sexes, after adjusting for confounders by multivariate stepwise logistic analysis, overweight mother (OR 2.54, 95 % CI 1.64-3.95), birth overweight (birth weight≥3,500g; OR 1.76, 95 % CI 1.15-2.69), the mother not responsible for taking care of the child (OR 1.65, 95% CI 1.10-2.48), overweight father (OR 1.62, 95%CI 1.09-2.40), eating snacks irregularly (OR 1.56, 95% CI 1.04-2.33), and gender (female;OR 0.51, 95% CI 0.34-0.77) had significant relationships with obesity in childhood. For boys, overweight mother (OR 2.53, 95 % CI 1.47-4.35), birth overweight (OR 2.03, 95%CI 1.22-3.39), eating snacks irregularly (OR 1.94, 95 %CI 1.19-3.18), and birth month (36-41 months; OR 0.47, 95 % CI 0.23-0.96) had significant relationships. For girls, overweight mother (OR 2.62, 1.28-5.35), and short sleep duration (OR 2.24, 1.11-4.52) had significant relationships. In neither Fisher's exact method nor multivariate logistic models, time to wake up, bedtime, duration of playing outdoors, regularity of meals, care about salty food, or frequency of eating snacks had significant relations with obesity in 3-year-old children (p<0.05).