A Population-based Study of Macronutrient Intake According to Mental Health Status with a Focus on Pure and Comorbid Anxiety and Eating Disorders

Purpose: Eating disorders (ED) and anxiety impact food choices. In addition, comorbid anxiety seems to increase ED symptoms and severity. However, the association between such comorbidity and dietary intake is unknown. This population-based, cross-sectional study aimed to assess macronutrient intake according to mental health status (i.e., no disorder, pure and comorbid anxiety and ED).

Methods: The study included N = 24,771 participants (74% female, mean age = 53.2 ± 13.7 years) in the NutriNet-Santé cohort, who completed once the trait subscale of the State-Trait Anxiety Inventory (STAI-T; high anxiety: ≥ 40 points) between 2013 and 2016 and the SCOFF questionnaire screening for ED in 2014. The Expali algorithm was applied to categorize ED (no ED; restrictive: RS; bulimic: BL; hyperphagic: HP; other ED). Participants were divided into ten groups by crossing their anxiety status (two groups: low or high) and their ED status (five groups). Macronutrient intakes were evaluated from ≥ 3 24-h dietary records. Analyses of covariance (ANCOVA) and Dunnett-Hsu tests (reference = no disorder) were performed.

Results: Significant differences in macronutrient intake were seen between the pure and comorbid forms, especially for RS and HP. Compared to the "no disorder" group, a significantly higher percentage of energy from carbohydrates, higher intakes of total carbohydrates, simple sugars, and plant-based protein, lower intakes of total fat, saturated and monounsaturated fatty acids, and cholesterol were observed in the comorbid anxiety + RS group, but not in the pure RS group. In contrast, significantly lower intakes of added sugar and plant-based protein, and a higher intake of cholesterol were observed in the pure HP group, but not in the comorbid anxiety + HP group. For BL and other ED, similar results were observed between the pure and comorbid forms.

Conclusion: This large epidemiological study provided some support for differences in macronutrient intake between individuals with pure or comorbid anxiety and ED. Differences in intake were largely dependent on ED type. Future prospective studies and studies using clinically defined anxiety and ED are needed to elucidate causality as well as potential effect modification of the observed associations.