According to the World Health Organisation (WHO) , overweight and obesity are the most important known avoidable causes of cancer after tobacco.
A strong relationship exists between obesity and breast cancer(and various other cancers). This co-relation is complex and not well understood.
Obesity has also been related to advanced disease at diagnosis and with a poor prognosis in both pre-menopausal and postmenopausal breast cancer
Weight gain is common, after receiving a breast cancer diagnosis, in many women . Weight gain and obesity lead to poorer breast cancer prognosis, worse surgical outcomes including higher infection rates, poorer healing, lymphedema, fatigue and functional decline.
Breast cancer–associated mortality is greater in women with higher BMI scores (body mass index [BMI] of 30 kg/m2 or higher).
Weight management plays a key role in the prevention of breast cancer and in improving the prognosis once breast cancer is diagnosed.
Achieving or maintaining a desirable body weight by
eating a healthy, well-balanced diet and regular exercise
may be one of the most important lifestyle behaviors in the
prevention of breast cancer and to improve
survival after a breast cancer diagnosis.
Breast Cancer Care and Support 