[Study on food preference and dietary behavior to overweight/obesity in school children and adolescents in Guangzhou: a case-control study].

Objective: This study assessed the effect of food preference and dietary behaviors on the risk of overweight or obesity in school children and adolescents aged 6 - 19 years.

Methods: All overweight or obese students, with age- and school-matched controls were recruited for this case-control study from 28 elementary and secondary schools in Guangzhou urban districts from October 2006 to April 2007. Weight and height were measured, and body mass index was calculated for the classification of obesity, overweight and underweight. Their food preference and behaviors were assessed using a structured questionnaire completed by their parents. Behavior and food preference were classified into four levels, and the relevant bottom levels were defined as control groups. Logistic regression was used to assess independent determinants of overweight and obesity.

Results: Among 7136 participants, 1947 cases and 2136 normal weight controls from 5755 students with valid questionnaire data were included in the study. Results from univariate analysis showed that odds ratios for overweight or obesity were 0.60-0.69 in those with most preference (top group) on vegetables, fruits, candy, evening snacks, 0.50 in the students of less food partiality, 1.84, 1.30 and 1.26 in those of most preference for pork, beef and deep-fried foods, and 5.14 in students with fastest speed during eating, respectively (all P < 0.05). Vegetable intake, evening snacks preference, speed during eating and food partiality remained with significant association with overweight and obesity in multivariate analysis after adjusted for age, sex, family socio-economical status and their parents' body build. The adjusted odds ratios (OR) and 95% confidence intervals (95%CI) of the above items became 0.55 (0.42 - 0.73), 0.48 (0.35 - 0.65), 0.50 (0.39 - 0.65), and 4.32 (3.23 - 5.80) as compared to the relevant lowest categories, respectively.

Conclusion: Behaviors as eating more vegetables and slow-eating might be protective factors against overweight and obesity in school children.