Is your weight loss diet triggering depression? Study warns of mental health risks

A recent study led by Gabriella Menniti at the University of Toronto has found a concerning link between calorie-deficit weight loss diets and increased depression risk.

The research, based on data from 28,525 adults participating in the US National Health and Nutrition Examination Survey (2007–2018), warns that while restrictive diets are popular for rapid fat loss, they may come at a mental health cost.

Participants were categorised into four groups: those not on any diet, those on calorie-restricted diets, people on nutrient-specific diets (such as low-carb or low-fat), and individuals following structured dietary patterns like DASH or diabetic diets. Depression levels were assessed using a standard questionnaire, with scores of 10 or above indicating significant mental health concerns.

The results showed that individuals on calorie-restricted diets were more likely to show signs of depression than those not following a diet. The mental health impact was more pronounced in overweight individuals. Notably, men appeared to experience more physical symptoms of depression—such as fatigue, disturbed sleep, and changes in appetite—than women.

Researchers pointed out that unlike clinical diet trials with balanced nutrient intake, real-world diets often result in nutritional deficiencies. These include insufficient protein, essential vitamins, and omega-3 fatty acids—factors that can impair brain function and contribute to depressive symptoms.

“Diets low in carbohydrates or fats may theoretically worsen brain function and cognitive-affective symptoms, particularly in men who have greater nutritional needs,” the study noted.

While prior research suggested weight loss might improve mood, this new analysis highlights the need for careful nutritional planning in calorie-deficit diets to avoid negative psychological effects.

(Disclaimer: This article is for informational purposes only and should not be considered medical advice. Always consult a healthcare professional before making dietary changes.)