Many of us embark on a journey to improve our health through diet, meticulously counting calories, cutting out carbs, or restricting certain nutrients. We often link these efforts to physical improvements, like shedding pounds or managing a chronic condition. But what if your pursuit of a healthier body is inadvertently taking a toll on your mind? New research reveals a surprising and potentially concerning link: restrictive diets, particularly calorie-cutting or nutrient-specific plans, may actually heighten depressive symptoms. And the impact seems to hit harder for certain groups: biological men and individuals who are overweight.
This provocative finding challenges the common perception that any form of “healthy” eating automatically benefits overall well-being. While a diet rich in whole, unprocessed foods, fruits, vegetables, and lean proteins is generally associated with a lower risk of depression, the picture becomes more complex when specific restrictions come into play. A recent study, published in the open-access journal BMJ Nutrition Prevention & Health, delves into the under-examined mental health consequences of these popular dietary approaches. It indicates that the very diets many adopt for health might, in some cases, be contributing to feelings of low mood, a lack of pleasure in activities, trouble concentrating, and even changes in sleep or energy levels. For those of us navigating the complex world of dietary choices, these insights underscore the importance of understanding the full spectrum of effects our food choices can have, far beyond the scale.
How Researchers Studied Diet and Mood
To understand this connection better, researchers looked at a large group of people at a specific point in time, using data from the U.S. National Health and Nutrition Examination Survey (NHANES) collected between 2007 and 2018. This survey is a well-known, nationwide study designed to assess the health and nutritional status of the American population, using methods that ensure its findings accurately reflect a wide range of people across the U.S.
The study included a substantial number of participants: 28,525 adults, almost evenly split between women (14,329) and men (14,196). All participants were aged 18 or older and had answered questions about their eating habits and how severe any depressive symptoms were. To measure depressive symptoms, the researchers used a widely recognized tool called the Patient Health Questionnaire-9, or PHQ-9. This questionnaire asks nine questions about specific symptom frequencies over a two-week period, with scores ranging from 0 to 27. A score of 10 or higher is typically seen as indicating meaningful depressive symptoms.
People’s eating patterns were sorted into four main groups based on their answers to questions like, “Are you currently on any kind of diet, either to lose weight or for some other health-related reason?”
- Calorie-restricted diets: This included anyone reporting they were on a weight loss or low-calorie diet.
- Nutrient-restricted diets: This group covered those on diets specifically low in fat/cholesterol, sugar, salt, fiber, or carbohydrates.
- Established dietary patterns: This category included diets prescribed by doctors, such as those for diabetes, or well-known healthy eating plans like the DASH diet.
- Not on a diet: The majority of participants (87.23%) fell into this group, reporting no specific diet.
The researchers also considered various other factors that could affect mental health, including age, background, education, marital status, income, smoking and drinking habits, food security, and existing conditions like diabetes and high blood pressure. This thorough approach helped them zero in on the potential impact of dietary choices on depressive symptoms.
Surprising Links Between What You Eat and How You Feel
The study’s results reveal a clear, though intricate, connection. Overall, nearly 8% of the participants reported experiencing depressive symptoms.
One of the most notable discoveries was that people following calorie-restricted diets had higher PHQ-9 scores, pointing to an increase in depressive symptoms, compared to those not on a specific diet. This suggests that simply cutting calories, a common weight-loss strategy, could be linked to a dip in mood.
The effect was particularly strong in overweight individuals. Among this group, both calorie-restricted diets and nutrient-restricted diets were associated with higher PHQ-9 scores. This implies that if you’re overweight and trying to lose weight by cutting calories or specific nutrients like carbs or fats, you might be at a higher risk for depressive symptoms. Interestingly, this connection wasn’t observed in individuals considered to be at a healthy weight or those who were obese.
Perhaps the most thought-provoking insight concerns biological men. While the general link between dietary patterns and depressive symptoms didn’t differ much between sexes, a closer look at specific types of symptoms brought something critical to light. Men on a nutrient-restricted diet showed a notable increase in what are called cognitive-affective symptom scores compared with women not following a diet. Cognitive-affective symptoms include feelings of sadness, anhedonia (loss of pleasure in things you usually enjoy), guilt, and difficulty concentrating. Also, men on any type of diet reported higher somatic symptom scores than men not on a diet. Somatic symptoms involve physical signs like sleep problems, low energy, appetite changes, and changes in movement or speech. The researchers theorize that “because biological men typically have higher caloric needs, restrictive diets may pose unique challenges that influence mood differently compared with biological women.” This idea is supported by earlier studies that show sex differences in how restrictive diets affect behavior.
It’s important to remember that this study observed existing patterns rather than conducting an experiment where people were assigned diets. This means it highlights a potential connection, but more research is needed to determine if restrictive diets directly cause depressive symptoms or if other factors are involved.
Key Takeaways for Your Health Journey
This study doesn’t tell us to give up on eating healthier. Instead, it offers a crucial reminder: the relationship between what we eat and our mental well-being is complex. For individuals, especially men and those who are overweight, starting restrictive diets without considering the possible mental health consequences could be counterproductive. The findings emphasize the vital need for a more all-encompassing approach to dietary advice. This means moving beyond simple calorie counting or cutting out certain nutrients and instead considering individual needs, biological differences, and the detailed impact of diet on both physical and mental health. This research provides valuable insights for doctors and dietitians, encouraging them to offer personalized dietary recommendations that take into account a person’s sex and body mass index (BMI) as potential factors for depression. Ultimately, it urges us to think carefully about our food choices, not just for our physical health, but for our overall mental well-being.
Paper Summary
Methodology
This cross-sectional study analyzed data from the U.S. National Health and Nutrition Examination Survey (NHANES) from 2007–2018. It included 28,525 adults who completed dietary assessments and the Patient Health Questionnaire-9 (PHQ-9) to assess depressive symptoms. Dietary patterns were self-reported as calorie-restricted, nutrient-restricted, established diets, or not on a diet.
Results
Among participants, nearly 8% reported depressive symptoms. Individuals on calorie-restricted diets showed increased depressive symptoms. Overweight individuals on both calorie-restricted and nutrient-restricted diets also experienced higher depressive symptoms. Biological men on any diet reported more physical symptoms (somatic), and those on nutrient-restricted diets had increased cognitive-affective symptoms compared to women not on a diet.
Limitations
This was a cross-sectional study, so it can only show associations, not cause-and-effect. Dietary information was self-reported, which can be inaccurate. Specific diet types were not always consistently available in the survey, and the term ‘diabetic diet’ was not clearly defined for participants. Underweight individuals were excluded due to small numbers.
Funding and Disclosures
The paper states: “Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.” No other specific funding or disclosures were provided within the text.
Publication Information
The article is titled “Mental health consequences of dietary restriction: increased depressive symptoms in biological men and populations with elevated BMI.” It was authored by Gabriella Menniti, Shakila Meshkat, Qiaowei Lin, Wendy Lou, Amy Reichelt, and Venkat Bhat. It was published as an open-access article in BMJ Nutrition, Prevention & Health on June 3, 2025, with the DOI: 10.1136/bmjnph-2025-001167.