Trying to eat healthier? You might also be feeding something else—your depression. A new study reveals that popular restrictive diets may have mental health costs, especially for men and people with higher BMI.
Key Points at a Glance
- Calorie-restricted diets are linked to increased depressive symptoms
- Men and overweight individuals appear most vulnerable to mood effects
- Restrictive diets may cause cognitive and somatic symptoms, like fatigue and low mood
- Real-world dieting differs dramatically from clinical diet plans in controlled trials
New research published in BMJ Nutrition, Prevention & Health suggests that restrictive diets—especially those cutting calories or nutrients—may quietly worsen mental health. Drawing on data from over 28,000 U.S. adults, researchers found that those on calorie-restricted or nutrient-restricted diets were more likely to report symptoms of depression. The effects were particularly strong in biological men and people with elevated BMI.
“It’s not just what you eat, but how restricting it impacts your mental state,” says lead author Gabriella Menniti. Unlike many controlled studies showing improved mood with healthy eating, this study focused on real-world dieting behavior—where deficiencies, poor adherence, and emotional strain are more likely.
Using data from the National Health and Nutrition Examination Survey (NHANES), researchers analyzed dietary patterns and depressive symptoms measured by the PHQ-9 questionnaire. The results were eye-opening: calorie restriction was associated with a 0.29-point increase in depressive symptom scores. Among overweight individuals, that number jumped to 0.46 points for calorie restriction and 0.61 points for nutrient-restricted diets.
For biological men, the emotional toll was even more pronounced. Those on nutrient-restrictive diets showed increased cognitive-affective symptoms like low mood and poor concentration. Calorie restriction also corresponded to higher somatic symptoms—such as fatigue, sleep issues, and low energy—compared to women not on diets.
“Men have higher baseline nutritional needs,” says co-author Venkat Bhat. “Restrictive eating can cause deficiencies in key nutrients like vitamin B12, iron, and omega-3s—all essential for brain health and energy metabolism.”
In essence, dieting may be causing hidden distress in the very people most likely to pursue it. Many overweight individuals attempt calorie- or nutrient-restricted diets in pursuit of better health. But when expectations clash with results, or when nutrient intake is inadequate, it may lead to emotional exhaustion or even depression.
The findings contrast with clinical trials where calorie restriction often improves mood. Why the discrepancy? Real life isn’t a lab. In clinical studies, diets are balanced and carefully managed. In reality, they’re often self-guided, inconsistent, and lacking critical support. People may feel isolated, frustrated, or nutritionally deprived—especially if they don’t see results.
“We need to be more honest about the mental health risks of dieting,” says Amy Reichelt, one of the study’s co-authors. “It’s not just about cutting calories—it’s about how that experience affects the person psychologically and physiologically.”
The study doesn’t suggest avoiding all dietary changes—but it does urge caution. Rather than adopting extreme restriction, especially without professional guidance, individuals should be aware of potential emotional impacts. The authors argue for personalized nutrition strategies that consider not just weight, but mood, sex, and lifestyle.
Ultimately, the findings could reshape dietary counseling. If certain populations—like men or people with high BMI—are more vulnerable to depressive symptoms while dieting, healthcare providers may need to tailor advice accordingly. What’s “healthy” for the body should also be healthy for the mind.
