Reduced Calorie Diets May Increase Risk of Depression Symptoms

Recent research published in the open-access journal BMJ Nutrition Prevention & Health indicates that following a low-calorie diet could be associated with a higher likelihood of experiencing depressive symptoms. The study analyzed data from over 28,500 adults participating in the US National Health and Nutrition Examination Survey (NHANES) between 2007 and 2018, focusing on their dietary patterns and mental health status.

Participants were categorized into different dietary groups, including calorie-restrictive, nutrient-restrictive, established dietary patterns, and those not on any specific diet. Findings revealed that individuals adhering to calorie-restrictive diets exhibited slightly higher scores on the Patient Health Questionnaire-9 (PHQ-9), indicating more severe depressive symptoms. This association was particularly pronounced among overweight and obese individuals, with calorie restriction linked to increased cognitive-affective and somatic symptoms.

Interestingly, the study found that men living with obesity and following nutrient-restrictive diets also showed higher depressive scores compared to healthy-weight counterparts. The research highlights that while traditional dietary advice promotes consuming minimally processed foods rich in omega-3 fatty acids, vitamins, and minerals, restrictive diets—especially when they lead to nutritional deficiencies—may have adverse effects on mental health.

The researchers caution that this is an observational study, meaning it cannot establish causality. Additionally, participants may have misreported their diets, and the findings seem to contrast with previous randomized controlled trials which typically show improvements in depression with calorie restrictions. The discrepancies could stem from real-life factors such as nutritional deficiencies and physiological stress caused by restrictive dieting or weight cycling.

Further explanations point to the importance of essential nutrients like glucose and omega-3 fatty acids for brain health. Diets low in these nutrients may impair cognitive function and worsen symptoms of depression, especially among men with higher nutritional needs.

Professor Sumantra Ray from the NNEdPro Global Institute emphasizes the need for further high-quality research to better understand this complex relationship. Ultimately, these findings suggest that restrictive dieting might have unintended mental health consequences, especially in vulnerable populations such as those with overweight or obesity.

Source: https://medicalxpress.com/news/2025-06-calorie-diets-linked-heightened-depressive.html