Influence of adolescents’ and parental dietary knowledge on adolescents’ body mass index (BMI), overweight/obesity in 2004–2015: a longitudinal study

Abstract

ObjectiveThe global epidemic of overweight/obesity in children and adolescents poses a significant public health threat. This longitudinal study aims to investigate the relationship between adolescents’ and their parents’ dietary knowledge and overweight/obesity among adolescents in China.MethodsData were collected from the China Health and Nutrition Survey (CHNS) in 2004, 2006, 2009, 2011 and 2015. Overweight/obesity was defined according to the International Obesity Task Force (IOTF) cut-off for body mass index (BMI). A set of questions were used to assess the dietary knowledge scores of both adolescents and their parents during face-to-face interviews. Mixed effect models were used to analyze the data.ResultsA total of 2035 adolescents aged 12–17 years were included in the data analysis. The mean BMI increased from 19.2 in 2004 to 20.5 in 2015, with a significant increase in the prevalence of overweight and obesity from 6.8% and 0.5% in 2004 to 15.1% and 7.8% in 2015, respectively. Adolescents with medium-score dietary knowledge were less likely to be overweight/obese compared to those with low-score dietary knowledge (OR (95% CI): 0.20 (0.05–0.80), P < 0.05). However, there was no association between parental dietary knowledge and adolescents’ BMI or overweight/obesity (P > 0.05). Additionally, a significant interaction between adolescents’ dietary knowledge score and education in relation to adolescents’ BMI (P for interaction < 0.05).ConclusionAdolescents with medium dietary knowledge were less likely to be overweight/obese than those with low knowledge, but no association was found with parental knowledge. Promoting nutritional education and healthy eating habits is vital to prevent overweight/obesity.