ISEO – Inaugural Conference July 22nd & 23rd 2026 - organized by DKFZ

The Effects of a Remote Diet and Exercise Intervention and Behavioral Change Constructs on Health Behaviors in the Prostate 8-II Randomized Controlled Trial

22 Jul 2026, 11:30

15m

Heidelberg Congress Center ( Heidelberg Congress Center )

3 - Talk Oral Session

Speaker

Stacey Kenfield (University of California, San Francisco (UCSF))

Description

Purpose: We evaluated if diet or exercise habits changed in a randomized controlled trial (RCT) of a remote behavior intervention vs. control, in men with prostate cancer. We assessed associations of behavioral change constructs with health behaviors.
Methods: Prostate 8-II is a RCT testing a remote diet and exercise intervention among 202 men with prostate cancer, opting for surgery at primary treatment, and not meeting all exercise/diet recommendations. The intervention included an interactive website, text messages, and health coaching. The control arm received print education. We used mixed effects models to assess intervention effects on the P8 diet score (higher=healthier) and meeting moderate to vigorous physical activity (MVPA) and P8-II resistance exercise guidelines (2+ d/wk, 8 exercises/session) at 6 and 12 months. We examined cross-sectional associations between baseline behavior constructs (social support, self-efficacy, perceived barriers, and use of change strategies) and baseline diet and exercise behaviors using multivariable linear and logistic regression.
Results: Among those with two-timepoint survey data, men randomized to the intervention (N~79) vs. control (N~83) increased their P8 diet score (p<0.001). A greater proportion of those randomized to exercise (N~91) vs. control (N~97) made improvements in meeting the resistance exercise recommendation (p=0.004); the exercise intervention did not improve MVPA between arms. At baseline, reporting more barriers was associated with lower step count (assessed via Actigraph GT3X+ accelerometers) and being less likely to meet MVPA guidelines; and use of change strategies was positively associated with MVPA guidelines. Higher self-efficacy for healthy eating was positively associated with P8 diet score.
Conclusions: The P8-II intervention increased the adoption of a prostate cancer-specific healthy diet and resistance exercise (vs. control). Future study will examine if changes in behavior were modified by behavioral constructs and evaluate the effect of the intervention on prostate-specific antigen levels.

Keywords

prostate, RCT, exercise, diet