Precommitment promotes healthier food choices under stress

Stress can result in unhealthier food choices with detrimental consequences for our health. Precommitment is a behavioural strategy whereby individuals restrict their future choice set and can promote healthier food choices - we may forgo buying cake when grocery shopping so we are not tempted to eat it at home. Yet, it is not known whether precommitment can buffer the effects of stress on food choices by providing opportunities to avoid unhealthy food altogether, enabling healthier food choices under stress. To investigate this, we developed a novel 'precommit-to-eat' paradigm which involved two stages. This enabled us to first assess precommitment decisions (precommitment stage) and, subsequently, participants' propensity to select healthier items to eat in a food choice stage (choice stage). Participants (n = 29) who all reported generally trying to eat healthily completed this two-stage paradigm twice - once under acute stress and once in a non-stressful control condition. The propensity to choose unhealthier but tastier food to eat increased with subjective stress, but this effect was counteracted by stress-related increases in precommitment. Thus, our findings show the effectiveness of precommitment under stress. This has important implications for interventions aimed at promoting healthier food choices, especially in stressful environments, that could particularly benefit individuals with lower dietary restraint.