Dietary patterns and change in food consumption in overweight or obese breast cancer survivors: the InForma randomized intervention trial

Background and aims: InForma is a randomized controlled trial designed to promote weight loss in overweight or obese breast cancer survivors by encouraging adherence to a healthy diet and/or increased physical activity. This secondary analysis evaluated its effects on dietary patterns, nutrients and food groups intake, over a two-year period. Methods and results: 260 breast cancer survivors with a BMI ≥25 kg/m2 were randomized into four arms: Dietary Intervention (DI), Physical Activity Intervention (PAI), Physical Activity and Dietary Intervention (PADI), and Minimal Intervention (MI). Participants were followed for 24 months and dietary intake and adherence to the Mediterranean diet were assessed throughout validated questionnaires (EPIC-FFQ, QueMD). Principal component analysis identified three baseline dietary patterns explaining 33.6 % of the variance: MEDITERRANEAN loaded heavily on “olive oil” and “vegetables”; SWEET on “cake, sweets”; and WESTERN on “red, processed meat”. Dietary factors contributing predominantly to each pattern decreased over follow-up visits, indicating an overall reduction in food consumption. Enrollment in DI and PADI arms compared to MI arm and being ≥60 years compared to <50 years, significantly predicted weight loss >5 %. Significant nutrient and energy intake reductions were observed, particularly at 6 months. Adherence to the Mediterranean diet improved in the whole study population, with no differences between intervention arms. Conclusion: A lifestyle intervention can promote significant reductions in energy and nutrient intake, and modifications in dietary patterns. This study provides new insights into the effectiveness of personalized lifestyle interventions in promoting long-term dietary changes among breast cancer survivors. Trial registration: ISRCTN53325751; ClinicalTrials.gov NCT02622711.