Macronutrient intake as a prospective predictor of depressive symptom severity: An exploratory study with adolescent elite athletes

Background: Appropriate availability of macro- and micronutrients has an important impact on cognitive performance, mood and mental health. Although the critical role of nutrition for elite athletes' performance was recognized early on, little is known about whether consumption of specific macronutrients (carbohydrates, proteins, fat) predict the development of future depressive symptoms in adolescent elite athletes. Methods: Participants were recruited from three Swiss Olympic Partner Schools (SOPS) in the Northwestern German speaking part of Switzerland. A total of 97 adolescent elite athletes (38% girls, Mage = 16.35 +/- 1.19) participated in the study. Depressive symptoms (PHQ9) were assessed at baseline and after 10 months follow-up. A 3-day food recall was completed three months after the baseline assessment. Linear regression analyses were used to examine whether macronutrients predict depression symptom severity after controlling for covariates and baseline depressive symptoms. Results: Higher protein consumption in athletes was a prospective predictor of lower depressive symptom severity at follow-up (beta = -35, p < .05). Several deviations from recommended nutritional standards were observed in elite athletes. Conclusions: The findings of this exploratory study support the notion that dietary behaviour may be prospectively associated with athletes' mental health. However, more research is required with larger samples and more in-depth assessment techniques. Future research should also examine whether nutrition education and dietary modification can be used to prevent depressive symptoms among adolescent elite athletes.