A study in Switzerland found that teenage athletes who ate more protein in their diets had lower levels of depressive symptoms. The study was published in Sport and Exercise Psychology.
The food we eat is made up of different components. These include what is called macronutrients such as carbohydrates, proteins and lipids, but also micronutrients like vitamins and minerals. Macronutrients are nutrients that humans need in large amounts, while micronutrients are needed in relatively small amounts. Both of these types of nutrients are essential to our health and well-being.
Appropriate intake of macro and micronutrients is linked to our cognitive performance, mood and mental health. Studies have shown that people with mental health issues often make poor food choices. This leads to inadequate diets. For example, people with severe mental illnesses have been found to be more prone to excessive food consumption and lower quality diets compared to the general population.
Study author Markus Gerber and his colleagues noted that the relationship between diet and depressive symptoms has not yet been thoroughly studied and that mental health is of extreme importance for athletes. They conducted a 10-month study to determine whether consumption of specific macronutrients (carbohydrates, proteins, fats) would predict the development of future depressive symptoms in elite adolescent athletes.
The participants in their study were 134 athletes, recruited from 3 Swiss Olympic partner schools in German-speaking Switzerland. These schools provide a special academic track for elite teenage athletes, giving them the opportunity to combine elite sport with formal education.
Participants completed the assessments twice – at the start of the study (August 2018) and a second time (end of June 2019). Participants were asked to create 3-day retrospective nutrition protocols in which they would list all the foods they ate during a 3-day period. The 3-day period was fixed to include 2 weekdays and 1 day during the weekend.
Research assistants visited all classrooms in participating schools and instructed students on how to create this protocol. This protocol allowed researchers to calculate total energy intake and the amounts of specific macro and micronutrients consumed. Participants also completed depressive symptom assessments, and researchers collected data on participants’ age, gender, body mass index, number of years they had been involved in competitive sports. , the weekly hours of training and competition, the nationality and the school path in which they were.
The results showed that at the start of the study, 13.9% of participants reported moderate to severe levels of depressive symptoms. At the second evaluation, about a year later, this percentage was 11.4% (11 versus 9 participants). Higher protein intake was associated with lower levels of depressive symptoms at the second assessment. Consumption levels of other types of macronutrients were not associated with depressive symptoms.
In addition, the researchers found that the total energy intake of the participants, given their high level of physical activity, was below the recommendations of the German, Austrian and Swiss nutrition societies. The same was true for the consumption of fats and polyunsaturated fatty acids. Sugar intake was above recommendations, while protein intake was adequate.
“The main finding of this exploratory study is that higher protein intake in adolescent athletes was found to be a prospective predictor of lower depressive symptom severity at follow-up,” the researchers concluded.
The study contributes to the body of knowledge on the relationship between diet and psychological factors. However, it also has limitations that must be taken into account. Namely, food intake was only assessed at one time and for three days, meaning that changes in diet quality over time could not be taken into account. In addition, the study design does not allow for any causal conclusions about the relationships between the factors studied.
The study, “Macronutrient intake as a prospective predictor of depressive symptom severity: an exploratory study with elite adolescent athletes,” was authored by Markus Gerber, Sarah Jakowski, Michael Kellmann, Robyn Cody, Basil Gygax, Sebastian Ludyga, Caspar Müller, Sven Ramseyer, and Johanna Beckmann.