Trends in Ultraprocessed Food Consumption Among Korean Children and Adolescents, 2007 to 2024

The prevalence of childhood obesity has tripled between 1999 and 2021, and the greatest increases have been observed in Asia. Ultraprocessed foods are considered a major risk factor for obesity; however, trends in ultraprocessed food consumption among Korean youths remain understudied.

To examine 18-year trends in ultraprocessed food consumption stratified by obesity and demographic characteristics among Korean youths.

This population-based cross-sectional study used 24-hour dietary recall data from 6 cycles of the Korea National Health and Nutrition Examination Survey from 2007 to 2024. Participants included Korean youths aged 1 to 18 years.

Survey cycles.

The percentage of energy intake from ultraprocessed foods based on the Nova food classification system was estimated across survey cycles.

Among the 24 518 youths included, the weighted mean (SD) age of participants was 10.2 (5.1) years, of whom 12 797 (52.2%) were boys. From the 2007-2009 to 2022-2024 cycles, the percentage of energy from ultraprocessed foods increased from 24.6% (SE, 0.5%) to 33.0% (SE, 0.5%) (P < .001 for trend), while the percentage of energy from unprocessed or minimally processed foods decreased from 64.8% (SE, 0.5%) to 51.8% (SE, 0.4%) (P < .001 for trend). There was a greater increase in ultraprocessed food consumption among school-aged children (from 22.9% [SE, 0.6%] to 34.0% [SE, 0.6%]) and adolescents (from 28.7% [SE, 0.8%] to 36.9% [SE, 0.7%]) than among preschool-aged children (from 23.5% [SE, 0.6%] to 26.4% [SE, 0.9%]) and among youths without obesity (from 24.7% [SE, 0.5%] to 33.5% [SE, 0.5%]) than those with obesity (from 24.9% [SE, 0.8%] to 30.9% [SE, 1.1%]) (P ≤ .001 for interaction).

In this cross-sectional study of Korean youths, the estimated proportion of energy intake from ultraprocessed foods increased from 2007 to 2024, indicating that ultraprocessed foods became a more dominant part of Korean youths' diets, especially among older youths and those without obesity. These findings suggest the need for monitoring and preventive strategies to reduce intake.