Abstract
Background: Food content pervades social media, yet how everyday exposure shapes momentary craving and snacking in daily life remains unclear. We tested whether experimentally adding unhealthy (H1) vs. healthy (H2) food content on top of participants’ Instagram feeds increased craving for and intake of unhealthy and healthy snacks, relative to adding art content (control). Method: In this preregistered randomized controlled field trial, 116 healthy-weight young adults (Mage = 22.46 years, 79.3% female) completed a 10-day smartphone ecological momentary assessment protocol (five prompts/day; five baseline, five manipulation days). Participants were randomly assigned to follow existing preselected Instagram accounts featuring unhealthy food, healthy food, or art (control); the number of additional accounts was 5% of those already followed. Outcomes (craving, consumption) were modeled using multilevel linear mixed models. Results: Manipulation checks confirmed expected shifts in food-related Instagram content. Against H1, added unhealthy content increased neither craving for (p = .194) nor intake of (p = .867) unhealthy snacks. Supporting H2, healthy food content increased craving for healthy snacks relative to both the control and the unhealthy condition (p < .001), but not healthy snack intake (p = .061). Conclusions: Curating a healthier Instagram feed may increase the desire for healthy snacks, but this effect, possibly due to the short duration of the manipulation, did not extend to intentions and/or intake. In conclusion, food craving may thus be used as early intervention target in future weight loss intervention, whereas changing actual intake likely requires longer or personalized exposure.