Assessment of nutrient intake, nutrition knowledge, and dietary habits by sports type among adolescent athletes at a physical education high school: a cross-sectional study

TL;DR

This cross-sectional study of 144 adolescent athletes at a Seoul physical education high school compared track-and-field (TF, n=76) and weight-class (WC, n=68) athletes on nutrient intake, nutrition knowledge, and dietary habits. Both groups underconsumed energy and carbohydrates relative to sports nutrition recommendations, while the WC group had better micronutrient diet quality but more harmful weight-control behaviors and poorer breakfast/carbonated-drink habits.

Key findings

• Both TF and WC groups had energy and carbohydrate intakes substantially below sports nutrition recommendations; protein intake was comparable between groups (1.3±0.4 g/kg/day) and similar to prior reports, and fat was approximately 30% of total energy intake.
• The WC group had significantly higher overall diet quality: mean adequacy ratio (MAR) was significantly higher than in the TF group (P<0.01), and nutrient adequacy ratios for energy, vitamin C, riboflavin, niacin, vitamin B6, folic acid, phosphorus, iron, and zinc were significantly higher (P<0.05); female WC athletes consumed significantly more energy than female TF athletes (P<0.05 in the abstract; P<0.001 in Results).
• Nutrition knowledge was low in both groups, with total NKQA scores of 27.9±14.0 (TF) and 29.4±15.7 (WC) showing no significant between-group difference, but the WC group scored significantly higher in dietary fat knowledge (P<0.05).
• The WC group showed more harmful dietary and weight-control behaviors: fewer ate breakfast daily (P<0.001), more drank carbonated drinks beyond three times per week (P<0.001), and more used fasting (31.1% vs. 8.7%, P<0.05); approximately 40% of the TF group and 50% of the WC group were currently losing weight.

Methods

• Cross-sectional study conducted April–May 2018; included 144 of 401 adolescent athletes aged 15–18 years at a physical education high school in Seoul, South Korea, divided into TF (n=76) and WC (n=68) groups.
• Nutrient intake was assessed using 3-day food records including the weekend, confirmed by direct interview and analyzed with CAN-Pro 5.0; dietary quality was calculated via NAR and MAR for 12 nutrients. Nutrition knowledge used the 109-item Nutrition Knowledge Questionnaire for Athletes (NKQA), and dietary habits, body image, and weight control used Korean Youth Risk Behavior Survey items.
• Statistical comparisons used Student t-test, chi-squared test, and ANCOVA adjusted for sex, age, BMI, athletic career, and weekly training duration; a sensitivity analysis excluded 64 participants classified as energy under-reporters (reported energy intake/EER <0.70).

Limitations

• Stated: self-reported food intake, dietary habits, and nutrition knowledge are subject to recall and social desirability bias; data were collected in 2018 and may not reflect current nutritional status; recruitment from a single high school limits generalizability; nutrient adequacy was evaluated using 2015 KDRIs despite the release of 2025 KDRIs.
• Evident: the cross-sectional design cannot establish causality or temporality between sports type and nutrient intake, nutrition knowledge, or dietary behaviors; under-reporting may affect energy and nutrient estimates, although the authors conducted a sensitivity analysis excluding under-reporters.