Comparing Appetite and Dietary Intake Responses to Resistance Exercise in Breast Cancer Survivors Undergoing Adjuvant...

Breast cancer survivors (BCS) undergoing adjuvant endocrine therapy have increased risk of obesity. Estrogen and exercise suppress appetite in non-BCS populations, but their combined effects in BCS are unknown. This secondary analysis compared the impact of acute resistance exercise (REx) on appetite and energy intake in estrogen-suppressed BCS versus females without cancer ('non-BCS'). Premenopausal inactive BCS (stage 0-III estrogen receptor-positive breast cancer, <5 years post-diagnosis, undergoing estrogen-targeted therapy) and non-BCS completed REx or sedentary (SED) conditions 35 min after a standardized breakfast. Appetite visual analog scales and hormones (ghrelin and peptide-YY [PYY]) were measured before and after breakfast and REx/SED; energy intake was assessed 3 h post-breakfast (1.5 h post-REx or SED). Fifteen BCS (age: 46 ± 7; BMI: 25.0 ± 3.8 kg/m²) and 12 non-BCS (age: 37 ± 8; BMI: 29.0 ± 5.1 kg/m²) were included. BCS showed greater PYY 90 and 120 min post-breakfast compared to non-BCS, particularly after REx (group x time x condition: p = 0.009, p = 0.005, respectively). No group effects were observed for ghrelin. BCS had lower body mass-adjusted energy intake compared to non-BCS (p = 0.036), despite similar appetite ratings. Estrogen-suppressed BCS exhibit heightened PYY and lower energy intake after REx, revealing novel effects of exercise on appetite in a state of low estrogen.