Secular trends in dietary patterns and obesity-related risk factors in Korean adolescents aged 10-19 years

Background: Along with its rapid economic growth, Korea has been undergoing considerable changes in the diet. But the influence of these changes on nutrition and health profiles has scarcely been investigated. Objective: We explored secular trends in dietary patterns to clarify their influence on obesity and its related risk factors among Korean adolescents using data from three consecutive Korean Nutrition Health and Nutrition Examination Survey (KNHANES). Design: Using data from the three KNHANES, 4347 adolescents (1572 from 1998, 1484 from 2001, and 1291 from 2005), who completed a 24-h diet recall, were included in the analysis. Percentiles of BMI were used to determine obesity; abdominal obesity was identified by waist circumference; and serum triglycerides and HDL-cholesterol = high density lipoproteins (HDL)-cholesterol were measured for obesity-related risk factors. Results: We identified evident three dietary patterns: 'traditional' (45.8% of total population), 'modified' (19%), and 'western' (35.2%). Secular trends were observed in dietary patterns, with a decline in the traditional diet pattern and gradual increases in the modified and western patterns. The percent of energy from fat increased over time, and it was positively associated with abdominal obesity in boys. The western dietary pattern increased the risk of being overweight (P = 0.05) and having elevated serum triglycerides (P = 0.07) in boys. Conclusions: Gradual changes over time in dietary patterns are occurring in Korean adolescents. The emerging western dietary pattern and high-fat intake could negatively affect the adolescent population studied here in later life; therefore, appropriate monitoring is suggested. International Journal of Obesity (2010) 34, 48-56; doi:10.1038/ijo.2009.203; published online 13 October 2009