A brief mindfulness intervention reduces unhealthy eating when hungry, but not the portion size effect

Objective: The present research examined the effects of a mindfulness-based intervention to foster healthy eating. Specifically, we tested whether a brief mindfulness manipulation can prevent the portion size effect, and reduce overeating on unhealthy snacks when hungry. Methods: 110 undergraduate participants (MAge = 20.9 ± 2.3; MBMI = 22.3 ± 2.5) were served a small or a large portion of chocolate chip cookies after listening to an audio book or performing a mindfulness exercise (i.e., body scan). Current level of hunger was assessed unobtrusively on a visual analog scale before the eating situation. Main outcome measure: Calorie intake from chocolate chip cookies. Results: When presented with a large compared to a small portion, participants consumed more cookies (+83 kcal). This was not affected by the mindfulness intervention or by hunger. However, while control participants ate more unhealthy food when hungry than when not hungry (+67 kcal), participants in the mindfulness condition did not (+1 kcal). Conclusions: Findings confirm the prevalence and robustness of the portion size effect and suggest that it may be independent from awareness of internal cues. Prevention strategies may benefit more from targeting awareness of the external environment. However, mindfulness-based interventions may be effective to reduce effects of hunger on unhealthy food consumption.