Lifestyle Behavioural Intervention on Breast Cancer Survivors for the Treatment of Overweight/Obesity.

The goal of this clinical trial is to compare a behavioural lifestyle intervention program (BL) to usual care (UC) in breast cancer survivors. The main questions it aims to answer are: 1. If the participants of the BL group will lose more weight than the UC group. 2. If the participants of the BL group will have more lifestyle benefits than the UC group. Volunteers will participate in a 24-week behavioural program. This program aims to improve their nutrition and physical activity in order to lose at least 10% of their initial body weight.

Eligible participants should be female breast cancer survivors between the ages of 18 and 65, with a BMI between 25 and 40 kg/m2, and no active cancer therapy or ongoing treatment, except for hormonal or immune therapy. The usual care (UC) group will receive WCRF cancer prevention recommendations. The behavioural lifestyle intervention program (BL) group will participate in a 24-week intervention targeting diet and physical activity to lose weight. The program will be considered successful if participants lose at least 10% of their initial body weight. A secondary goal is to improve their nutrition and physical activity levels. The third and last goal is to improve their overall quality of life and their anxiety levels. The behavioral program includes in-person online meetings, group online sessions, and digital counseling material. Considering that participants will be residing all around Greece, an internet videoconferencing technology will be required. A qualitative study incorporating focus groups undertaken prior to this study to establish the methodology resulted in the utilization of synchronous and asynchronous media, as well as a combination of in-person and group sessions.