Can Cutting Calories Increase the Risk of Depressive Symptoms? Study Sheds Light - Video

Following a low-calorie diet may be linked to an increased risk of depressive symptoms, particularly in men and those who are overweight, according to new research published in the open-access journal BMJ Nutrition, Prevention & Health. The study draws attention to the mental health risks associated with restrictive diets that are commonly followed for weight loss or medical reasons.

For the study, researchers analysed data from 28,525 adults who participated in the US National Health and Nutrition Examination Survey between 2007 and 2018. All participants had completed the Patient Health Questionnaire-9, a validated tool used to assess depressive symptoms.

The study found that participants on calorie-restrictive diets had PHQ-9 scores that were 0.29 points higher than those not on any specific diet. Among overweight individuals, the scores were even higher—up to 0.46 points with calorie restriction and 0.61 with nutrient-restrictive diets. These dietary patterns were also associated with elevated cognitive-affective and somatic symptom scores, particularly among men.

The findings appear to contradict earlier clinical trials that suggested low-calorie diets improve mood. However, researchers explained that “this discrepancy may arise because prior studies were primarily randomised controlled trials (RCTs) where participants adhered to carefully designed diets ensuring balanced nutrient intake. In contrast, real-life calorie-restricted diets and obesity often result in nutritional deficiencies and induce physiological stress, which can exacerbate depressive symptomatology including cognitive-affective symptoms.” Another possible explanation might be a failure to lose weight or weight cycling—losing weight and then putting it back on, they suggest.

They also noted gender differences, suggesting that men’s higher nutritional needs, particularly for glucose and omega-3 fatty acids, may explain their increased vulnerability to mood disturbances from restrictive diets.

Reference: Gabriella Menniti, Shakila Meshkat, Qiaowei Lin, Wendy Lou, Amy Reichelt, Venkat Bhat - Mental health consequences of dietary restriction: increased depressive symptoms in biological men and populations with elevated BMI: BMJ Nutrition, Prevention & Health 2025;:bmjnph-2025-001167.