Preliminary effects of an online diet, walking, and mindfulness-integrated lifestyle intervention for breast cancer survivors with overweight or obesity: A pilot randomized controlled trial.

Objective: To examine the preliminary effects of an online intervention integrating diet, walking, and mindfulness, compared with diet and walking alone, on weight-related outcomes in breast cancer survivors. Methods: This pilot randomized controlled trial enrolled women with stage I-III breast cancer and a body mass index ≥ 24 kg/m Results: Forty-two participants were enrolled, with 21 assigned to each group. Both groups showed reductions in body weight, waist circumference, and body fat percentage over 12 months. The DWM group showed a more favorable pattern of body weight change over time than the DW group, with a significant overall group × time interaction. For waist circumference and body fat percentage, both groups improved over time, but between-group differences were not consistently supported by the overall interaction tests; exploratory time-specific estimates suggested possible differences at Week 48. Engagement was similar between groups. More frequent dietary recording was associated with greater reductions in body weight and body fat percentage. Conclusions: This pilot trial provides preliminary evidence that an online intervention integrating diet, walking, and mindfulness may be associated with a more favorable long-term pattern of body weight change in breast cancer survivors. Evidence for differential effects on waist circumference, body fat percentage, and psychosocial outcomes was limited, and the contribution of mindfulness-specific mechanisms remains uncertain. Larger, adequately powered trials with longer follow-up and more targeted process measures are needed. Trial registration: ClinicalTrials.gov Identifier: NCT06427473.