A Randomised Controlled Trial Comparing the Effects of Personalised Diet and Physical Activity Intervention Versus...

Background: Adults with inflammatory bowel disease (IBD) have a high prevalence of modifiable cardiometabolic risk factors. This study investigates the impact of a personalised diet and physical activity intervention versus usual care on the risk factors. Methods: A 6-month randomised controlled trial was conducted at three hospitals in New Zealand (NZ) from 2023 to 2024. Adults with IBD in remission, a body mass index > 25 kg/m², and a low fibre intake < 25 g/day were recruited. Participants were randomised to receive either generic healthy eating and physical activity education or personalised heart-healthy eating education based on the NZ Heart Foundation and a self-led physical activity program. The primary outcome was change in body fat, and secondary outcomes included disease activity, biomarkers, quality of life, physical activity, and dietary intake. Between-group differences were analysed using multivariable regression. Results: Sixty-four participants were randomised, and 51 (80%) completed the intervention. The median age was 47 years (LQ, UQ: 37, 55), 59% participants were female, 61% had Crohn's disease, and 85% had faecal calprotectin < 150 µg/g. Common cardiometabolic risks were high waist circumference (88%) and abnormal lipid profile (56%). There were no significant differences in primary or secondary outcomes except for dietary intakes: increased fruit (0.5 serves/day; 95% CI: 0.1, 1.0) and dietary fibre (3.1 g/1000 kcal/day; 95% CI: 1.1, 5.1); reduced discretionary food and drink (-1.7 serves/day; 95% CI: -3.0, -0.3), and sodium (-911 mg/day; 95% CI: -1783, -40). Conclusions: Personalised dietitian advice led to meaningful dietary changes without exacerbating disease activity. More intensive activity modalities can be recommended to support body composition improvements.