Improvements in stage of change correlate to changes in dietary intake and clinical outcomes in a 5-year lifestyle intervention in young high-risk Sri Lankans

The objectives of a stage-matched approach to lifestyle change are that individuals progress forward through the stages of change. It also posits that progression through the stages of change is associated with positive changes in lifestyle behaviours. Measuring the relationship between stage of change and food intake is challenging due to the plurality of dietary behaviours. Furthermore, it is not clear whether changes in behaviour are sustained long-term. In this study we assess the movement through stages of change in the intensive (visits every 3 months) and control groups (visits annually) of a large-scale primary prevention study in cardiovascular disease, carried out in 2637 children and young adults in Sri Lanka between 2007 and 2012. We also examine their relationship to dietary behaviours and clinical outcomes. We demonstrate that individuals in both groups continue to progress through stages of change over the course of the study and that measures of dietary behaviours improved from baseline to final follow-up. We also demonstrate that stage of change positively correlates to dietary behaviours including the ratio of recommended:not-recommended items, unpolished:polished starches and low-fat:high-fat food items throughout each year of the study. Finally, participants in the later stages of change at Y2, Y3 and Y4, had a significantly attenuated increase in weight and waist circumference at the final visit in both groups. We therefore demonstrate the usefulness of stage-matched approach in modifying complex dietary behaviours, and that stage of change is a valid measure of dietary behaviours across a large population over time.