A Prolonged Nightly Fasting Plus Telehealth Coaching Intervention (PNF+) for Men on Androgen Deprivation Therapy for PCa: A Pilot Feasibility Randomized Controlled Trial

Background/Objectives: This study aimed to assess the feasibility and acceptability of a 3-month health coaching intervention to promote PNF and healthy diet for men on ADT for PCa. Methods: The study was carried out via a two-armed randomized controlled trial including 40 patients with PCa at a medical center in Philadelphia. During the 3-month period, the intervention group (PNF+) received health coaching utilizing an interactive text message system, and the control group received healthy eating text messages for the same duration. The outcome variables were feasibility and acceptability. Results: The PNF+ group (n = 27) had high adherence to health coaching (82%), picture response (85%) and moderate adherence to the PNF window (69%). The intervention was rated highly acceptable with no reported A/E associated with the intervention, and most participants planning to continue in some capacity. At 3 months, the PNF+ group had numerically lower BMI (29.1) and body weight (195.2 lbs) compared to the control group (n = 13; BMI 31.6, weight 223.3 lbs). Improvements in patient-reported outcomes were observed in both groups. FACIT-F scores (higher scores indicate less fatigue) increased in the PNF+ group (43.6 to 45.2) and in the control group (42.5 to 45.5). FACT-P scores (higher scores indicate better quality of life) increased in the PNF+ group (121.3 to 125.5) but decreased slightly in the control group (121.1 to 119.8). Between-group comparisons of change from baseline showed no statistically significant differences across outcomes (all p > 0.05). Conclusions: The intervention demonstrated partial feasibility and high acceptability. It was associated with numerically lower BMI and body weight and favorable changes in patient-reported outcomes, particularly quality of life; however, no statistically significant differences were observed between groups. These findings should be interpreted cautiously given the small sample size and require confirmation in larger, adequately powered trials.