Reduced adipose tissue with limited loss of lean mass after weight loss: results from the Prostate Cancer Active Lifestyle Study.

Adiposity reduction has cancer-specific and overall health benefits for patients with overweight or obesity. The indiscriminate loss of lean mass accompanying weight loss, however, remains a concern for older patients with cancer. Body composition was evaluated in the Prostate Cancer Active Lifestyle Study, a randomized controlled weight loss trial targeting caloric restriction and increased physical activity among patients with prostate cancer and overweight or obesity on active surveillance. Compared with control individuals, the intervention statistically significantly decreased total fat (‒3.4%, 95% CI = ‒5.3% to ‒1.5%), android fat (‒2.0%, 95% CI = ‒3.6% to ‒0.4%), and visceral adipose tissue mass (‒613 g, 95% CI = ‒894 to ‒331 g) (all 2-sided P < .001), with no difference in lean mass (P = .70) and a statistically significant increase in lean mass to fat ratio (0.40, 95% CI = 0.06 to 0.73; 2-sided P = .02). Weight loss interventions incorporating diet and physical activity among patients with prostate cancer and overweight or obesity can yield statistically significant reductions in adiposity while limiting lean mass loss.