Effect of a diet and physical activity intervention on body weight and nutritional patterns in overweight and obese breast cancer survivors

Energy restriction from a low-calorie diet and increased energy expenditure induced by physical activity (PA) could promote weight loss/maintenance and be important determinants of breast cancer (BC) prognosis. The aim of this study was to assess participation and adherence of overweight and obese BC survivors to a lifestyle intervention and to demonstrate the capacity of this intervention to induce weight loss and nutritional changes. This single-arm pre-post study, which involved one-hourly weekly diet sessions delivered by a dietician and 75-min bi-weekly PA sessions of moderate-to-high intensity led by PA monitors, was offered to overweight and obese BC survivors shortly after treatment. Before and after the intervention, anthropometry, dietary information, quality of life (QoL) and cardiorespiratory fitness (CRF) were collected. A total of 112 BC survivors were invited to participate: 42 of them started the intervention and 37 completed it. Participants attended more than 90 % of the sessions offered and showed a significant weight loss of 5.6 ± 2.0 kg, as well as significant decreases in body mass index, fat mass and waist circumference. Significant decreases in total energy (-25 %), fat (-35 %), saturated fat (-37 %) and carbohydrate (-21 %) intakes were observed while QoL and CRF showed significant increases. This feasibility study demonstrated the success of a short-term diet and PA intervention to induce weight loss and promote healthful changes in BC survivors. Assessing the long-term effects of these changes, and in particular their possible impact of BC prognosis, and designing interventions reaching a wider number of BC survivors are still issues to be addressed.