Both weight loss and low-carbohydrate diets (LCD) without weight loss prolong survival in prostate cancer models. Few human trials have tested weight loss or LCD on prostate cancer.Experimental Design: We conducted a multi-site randomized 6-month trial of LCD versus control on PSA doubling time (PSADT) in patients with prostate cancer with biochemical recurrence (BCR) after local treatment. Eligibility included body mass index (BMI) ≥ 24 kg/m 2 and PSADT 3 to 36 months. The LCD arm was instructed to eat 20 g/carbs/day; the control arm instructed to avoid dietary changes. Primary outcome was PSADT. Secondary outcomes included weight, lipids, glucose metabolism, and diet.Results: Of 60 planned patients, the study stopped early after an interim analysis showed futility. Twenty-seven LCD and 18 control patients completed the study. At 6 months, although both arms consumed similar protein and fats, the LCD arm reduced carbohydrates intake (À117 vs. 8 g, P < 0.001) and lost weight (À12.1 vs. À0.50 kg, P < 0.001). The LCD arm reduced HDL, triglycerides, and HbA1c with no difference in total cholesterol or glucose. Mean PSADT was similar between LCD (21 months) and control (15 months, P ¼ 0.316) arms. In a post hoc exploratory analysis accounting for prestudy PSADT, baseline PSA, primary treatment, and hemoconcentration, PSADT was significantly longer in LCD versus control (28 vs. 13 months, P ¼ 0.021) arms. Adverse events were few, usually mild, and returned to baseline by 6 months.Conclusions: Among BCR patients, LCD induced weight loss and metabolic benefits with acceptable safety without affecting PSADT, suggesting LCD does not adversely affect prostate cancer growth and is safe. Given exploratory findings of longer PSADT, larger studies testing LCD on disease progression are warranted.

Background Women have higher rates of obesity than men and develop more pronounced functional deficits as a result. Yet, little is known about how obesity reduction affects their functional status, including whether their responses differ when protein intake is enhanced. Objective The aim of this study was to confirm the feasibility of delivery of a higher-protein (balanced at each meal) calorie-restricted diet in obese women and determine its efficacy for influencing function and retention of lean mass. Method Obese community-dwelling women [n = 80; body mass index (in kg/m2), in means ± SDs: 37.8 ± 5.9; aged 45–78 y; 58.8% white] were enrolled in a weight-loss (−500 kcal/d) study and randomly assigned to either a Control–Weight-Loss (C-WL; 0.8 g protein/kg body weight) group or a High-Protein–Weight-Loss (HP-WL; 1.2 g protein/kg body weight; 30 g protein 3 times/d) group in a 1:2 allocation. Primary outcomes were function by 6-min walk test (6MWT) and lean mass by using the BodPod (Life Measurement, Inc.) at 0, 4, and 6 mo. Results Both groups reduced calorie intakes and body weights (P < 0.001), and the feasibility of the HP-WL intervention was confirmed. The 6MWT results improved (P < 0.01) at 4 mo in the HP-WL group and at 6 mo in both groups (P < 0.001). Both groups improved function by several other measures while slightly decreasing (P < 0.01) lean mass (−1.0 kg, C-WL; −0.6 kg, HP-WL). Weight loss was greater in white than in black women at both 4 mo (6.0 ± 3.6 compared with 3.7 ± 3.4 kg; P < 0.02) and 6 mo (7.2 ± 4.8 compared with 4.0 ± 4.7 kg; P < 0.04) and tended to be positively related to age (P < 0.06). Conclusions A clinically important functional benefit of obesity reduction was confirmed in both study groups, with no significant group effect. Our findings of racial differences in response to the intervention and a potential influence of participant age lend support for further studies sufficiently powered to explore the interaction of race and age with functional responses to obesity reduction in women. This trial was registered at clinicaltrials.gov as NCT02033655.

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