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It’s not a secret that what you eat affects your body, but did you know that having a balanced diet also affects your brain, mood, and energy? In this blog post, we’ll explore the scientific evidence that shows how nutrition and healthy eating can directly impact your mental health.
Depression and anxiety are considered the most common mental health conditions worldwide, with research showing that adolescent depression in the United States has risen from 8.1% in 2009 to 15.8% in 2019. Anxiety disorders are also considered the most common mental illness in the United States, developing from a complex set of risk factors, and affecting both adolescents and adults.
Considering the prevalence of depression and anxiety among teens in the US, it is vital to examine the approaches to managing these conditions, as well as the factors that can improve mental health.
A recent study published in 2020 by Firth et al., which examined epidemiological research on dietary patterns and mental health, states that a healthy, balanced diet, including a high consumption of fruits, vegetables, nuts, and legumes, is associated with a reduced risk of depression. They also acknowledge that the relationship between diet and mental health is very complex and multidirectional, containing effects from both scientific factors, like brain health and immune system activation, as well as financial and environmental determinants of health.
For example, clinical studies have shown that refined carbohydrates, like white bread, cakes, chips, etc, can have a negative causal effect on mood, meaning that a diet heavy on these foods can potentially increase depressive symptoms and worsen mood. The science behind this explains that a high consumption of processed carbohydrates leads to a high glycemic index, leading to a greater release of hormones like cortisol and adrenaline, which may cause changes in anxiety and irritability.
Another scientific connection to diet and mental health explores the effects of immune activation. Specifically, studies show that high calorie meals rich in saturated fat appear to stimulate immune activation and a heightened inflammatory response, and they propose that this may be one mechanism that causes negative effects on brain health. Additionally, since certain mental health conditions, like mood disorders, have been linked to heightened inflammation, this finding can also explain how a poor diet can increase the risk of depression.
However, considering all of this info provided by these research studies, it is also very important to acknowledge that diets that are too restrictive can actually make depressive symptoms worse. Therefore, one-size-fits-all diets are not exactly the solution and may negatively impact mental health. Everyone has their own individual nutritional needs, and diets that are too restrictive, especially with strict calorie or nutrient limitations, can lead to lower energy levels, poor sleep, and can negatively impact brain function. Notably, the study by Firth et al. explicitly recognizes that changes in food choices or preferences in response to our psychological state, including “comfort foods” when your mood is low and appetite changes during high stress, is a common human experience. Thus, the common saying, “Everything in moderation,” seems to be science-backed and a very important take-away message.
Ultimately, the various analyses and multiple research studies show that it is important to find a balance in healthy eating, prioritizing a diet focused on fruits, vegetables, whole grains, and lean proteins, while also avoiding diets that are too restrictive, in order to have the most beneficial impact on mental health.
References:
Firth, J., Gangwisch, J. E., Borisini, A., Wootton, R. E., & Mayer, E. A. (2020, June 29). Food and mood: How do diet and nutrition affect mental wellbeing?. BMJ (Clinical research ed.). https://pmc.ncbi.nlm.nih.gov/articles/PMC7322666/
Wilson, S., & Dumornay, N. M. (2022, March). Rising rates of adolescent depression in the United States: Challenges and opportunities in the 2020s. The Journal of adolescent health : official publication of the Society for Adolescent Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC8868033/
Anxiety disorders – facts & statistics. Anxiety and Depression Association of America (ADAA). (n.d.). https://adaa.org/understanding-anxiety/facts-statistics
Menniti, G., Meshkat, S., Lin, Q., Lou, W., Reichelt, A., & Bhat, V. (2025, June 3). Mental health consequences of dietary restriction: Increased depressive symptoms in biological men and populations with elevated BMI | BMJ Nutrition, Prevention & Health. BMJ Nutrition, Prevention & Health Journals. https://nutrition.bmj.com/content/early/2025/05/28/bmjnph-2025-001167
Storey, D. (2025, June 6). Restrictive diets could make depression worse. Psychiatrist.com. https://www.psychiatrist.com/news/restrictive-diets-could-make-depression-worse/