Sugar Habit Hacker: A Pilot Randomised Controlled Trial of Personalised Normative Feedback to Change Sugar Consumption

Background: Excessive sugar consumption is a major public health concern, yet effective, scalable interventions remain limited.

Aim: To explore the effects of a brief online intervention of personalised normative feedback (PNF) on sugar consumption, mental well-being, craving, and self-efficacy at one and two months in New Zealanders.

Methods: Random assignment was to PNF on sugar consumption with feedback on mental wellbeing, craving, and self-efficacy scores, and information on strategies for change or a personalised summary of total sugar consumption and scores on measures. The main outcome was change in sugar intake from baseline, assessed using a self-reported Food Frequency Questionnaire (FFQ). Secondary outcomes were change in craving strength, craving frequency, self-efficacy and mental well-being.

Results: A total of 605 participants were recruited over a four-week period. Most participants were female (86%), aged >45 years (56%), and consumed sugar within the recommended 10% daily energy intake limit (72%). Sugar consumption reduced by 10.2% at one-month post-intervention (Cohen's d = −0.27; 95% CI [−0.43, −0.11]), and this change was maintained at two months. Improvements were found for all secondary outcomes except mental well-being. There were, however, no significant group-by-time interactions for sugar intake or other outcomes.

Conclusion: PNF shows promise in improving sugar consumption, but outcomes were similar to offering a personalised summary of scores alone. Given rapid recruitment and strong retention, future research should compare these conditions with a true control group that provides no feedback. Further work should also examine the reliability and validity of the FFQ for measuring sugar consumption.