A modified Trier Social Stress Test enhances cortisol release, but not energy intake, in females: A randomized trial

Cortisol has been linked to increased energy intake, a phenomenon colloquially referred to as "stress eating". Laboratory stress paradigms, however, often elicit inconsistent cortisol responses and have limited generalizability. Enhancing cortisol reactivity and the external validity of stress paradigms may improve the knowledge gained from laboratory studies on stress-induced eating. This study aimed to enhance anticipatory stress and realism, thereby elevating cortisol reactivity and energy intake. Female participants (N = 87) were randomly assigned to a modified Trier Social Stress Test (TSST), the original TSST, or a no-stress condition. Participants in the modified TSST were told that they would undergo an initial interview to determine their eligibility for the study, but otherwise it was identical to the original TSST. Snacks were provided either at the start of or after the stressor and visit energy intake was measured. In addition, a dietary recall was conducted for evening intake. Stress measurements, including salivary cortisol, heart rate, systolic blood pressure, and anxiety, were taken throughout the visit. The modified TSST, unlike the original TSST, elevated cortisol levels above baseline, although cortisol reactivity did not correlate with energy intake. Systolic blood pressure and anxiety were higher at baseline in the modified TSST, indicating greater anticipatory stress. Energy intake during the lab visit was not affected, but evening intake was higher after the original TSST. Therefore, studies that require a reliable cortisol response should consider this new protocol; however, studies that focus on stress-induced energy intake may prefer the original TSST. In addition, novel insights were found on temporal patterns of stress-related eating, showing the importance of measuring energy intake on a longer timeframe than is currently practiced.