Short Daily Texts Raised Teens’ Plant-Based Lunch Choices to 59%, AI Style-Matching Added No Extra Effect

A randomised controlled trial found that brief, fact-based messages sent to adolescents' phones increased the share of plant-based school lunches chosen from 44% to 59% over a two-week period. However, rewriting the messages in each teenager's own texting style using a large language model did not have any additional effect on lunch choices. The study, conducted with 586 adolescents aged 11 to 16 in the UK and the Republic of Ireland, showed that plain messages performed just as well as tailored ones in promoting healthier and more sustainable dietary choices.

Participants received messages from a fictional influencer containing evidence-based facts about health, the environment, or animal welfare without moral framing. The findings suggest that concise, fact-based digital messages can be effective in influencing teenagers' dietary choices, with tailored messages not significantly outperforming standard ones. This study highlights the importance of message content in promoting healthier and more sustainable dietary choices among adolescents, showing that personalization through AI styling did not provide any additional benefit in this context.