High/low cortisol reactivity and food intake in people with obesity and healthy weight

Increased food intake, termed "comfort eating", is a pathologic coping mechanism in chronic stress. Cortisol reactivity under stress is a potent predictor of stress-induced eating behavior affecting the body mass index (BMI). However, cortisol reactivity and food intake under stress in people with obesity has not been evaluated. The aim of this study was to investigate the effect of high/low cortisol reactivity on food intake in people with obesity and healthy weight test controls, following standardized stress induction and a resting condition. Thirty-six men and women with obesity (BMI: 33.00 ± 3.23 kg/m²), as well as 36 age- and gender-matched healthy weight controls (BMI: 21.98 ± 1.81 kg/m²) were categorized into high cortisol reactors (HCR) and low cortisol reactors (LCR) in the Trier Social Stress Test (TSST). Following the TSST and a resting condition, the food intake of all participants was recorded in a standardized laboratory meal. Obese HCR demonstrated a significantly higher food intake than LCR (t (34) = -2.046, p ≤ 0.05). However, there were no significant differences between HCR and LCR in the healthy weight controls (p = 0.26). In addition, HCR of the people with obesity showed lower values in the emotion coping strategy of cognitive reappraisal than obese LCR (t (32) = 2.087, p ≤ 0.05). In conclusion, the magnitude of the cortisol reactivity to stress predicts stress-induced food intake in people with obesity, but not in the healthy weight controls. Limited use of cognitive reappraisal in emotion regulation in the obese HCR may be a marker of vulnerability to stress-induced eating.