Lower body weight and being physically active could reduce risk of dying from breast cancer

25 October 2022

Published today in the International Journal of Cancer*, a major review of published research has found that certain key factors could impact the risk of death for women after a breast cancer diagnosis.

As part of World Cancer Research Fund International’s Global Cancer Update Programme, housed at Imperial College London, the review sought to understand the links between body weight, physical activity, diet and the risk of death after a breast cancer diagnosis.

Key findings of the review after a breast cancer diagnosis

Body weight

  • Strong evidence that higher body weight, after diagnosis, increases the risk of death.
  • 226 studies were analysed from around the world, comprising more than 456,000 women with breast cancer; among them, 36,000 died, 21,000 of breast cancer.

Physical activity

  • Some evidence that being more physically active could reduce the risk of death after a breast cancer diagnosis.
  • Some evidence that physical activity could reduce the risk of breast cancer recurrence.
  • 23 studies were analysed from around the world, comprising more than 39,000 women with breast cancer; among them, around 5,000 died, 2,000 of breast cancer.

Most studies looked at recreational physical activity, such as aerobics, walking and running, with limited studies on other types of activity.


  • Some evidence that eating more dietary fibre could reduce the risk of death.
  • Some evidence that eating soy could reduce the risk of death, as well as breast cancer recurrence.
  • Some evidence that people with certain healthy eating patterns* have a reduced risk of death.
  • 108 studies were analysed from around the world, comprising more than 151,000 women with breast cancer; among them, 14,900 died, 5,900 of breast cancer.

Breast cancer is the most common type of cancer among women in the UK, with 56,987 new cases in 2019. Three in 10 new cases of cancer in women in 2019 was breast cancer.

In 2020, globally, breast cancer was the most common cancer among women. There were an estimated 2.3 million cases and 700,000 deaths. As of the end of 2020, there were 7.8 million women worldwide living at least five years after a breast cancer diagnosis.

Researchers and healthcare professionals are invited to join a panel of experts who contributed to the breast cancer reviews at a Hot Topics in Nutrition & Cancer: Diet and Breast Cancer Survivorship on the 25 October 1:00–2:30 PM ET (6:00–7:30pm BST).

Dr Helen Croker, Head of Research Interpretation at WCRF International, said:

For over 20 years our Recommendations have supported the creation of an environment where individuals can pursue, and governments can support, healthier choices to reduce cancer risk.

We now hope to develop a set of recommendations specifically for people living with and beyond cancer so that, alongside their healthcare team, they have the latest evidence-based information about healthy eating, physical activity and weight. Analysing and interpreting the existing literature is the first step towards these efforts.

Nikki Bednall, diagnosed with stage 3 breast cancer in 2017, said:

After my diagnosis and treatment, I made a few lifestyle changes to reduce my risk of health problems. These included maintaining a healthy weight, eating a variety of healthy foods and exercising regularly.

I know from experience the feeling of jumping through hoops after a cancer diagnosis. However, as the evidence from these reviews gets stronger it gives me greater confidence that there are things I can do to help improve my chances of living beyond my breast cancer.

Dr Doris Chan, co-author at Imperial College London, said:

Many women living with breast cancer seek lifestyle advice. It is important that they have access to reliable information about healthy living.

The findings from these reviews strengthen the case for women with breast cancer to be supported by their healthcare team to make positive behaviour changes. These could include eating a healthier diet and being physically active, all of which play a role in maintaining a healthy weight.


For all media enquiries contact please contact Melanie Marks Purnode at m.purnode@wcrf.org

Notes to editors

*All four published papers can be found here:

Post-diagnosis body fatness, recreational physical activity, dietary factors and breast cancer prognosis: Global Cancer Update Programme summary of evidence grading. https://doi.org/10.1002/ijc.34320

Post-diagnosis recreational physical activity and breast cancer prognosis: Global Cancer Update Programme systematic literature review and meta-analysis. https://doi.org/10.1002/ijc.34324

Post-diagnosis body fatness, weight change and breast cancer prognosis: Global Cancer Update Programme systematic literature review and meta-analysis. https://doi.org/10.1002/ijc.34322

Post-diagnosis dietary factors, supplement use and breast cancer prognosis: Global Cancer Update Programme systematic literature review and meta-analysis. https://doi.org/10.1002/ijc.34321

** In these studies, the dietary patterns were specific patterns such as a low fat and high fibre/ fruit/ vegetable diet and following the WCRF/ AICR Cancer Prevention Recommendations.

“Body weight” is a simplified term to cover a range of anthropometric measurements in the review including body mass index (BMI), waist circumference and waist-hip-ratio.

“Some evidence” refers to a ‘limited suggestive’ conclusion. This means that there is evidence of an effect but there are issues with the evidence which could include the amount of research available or the quality of the research. The Panel of experts uses a grading criteria to ensure the evidence is judged appropriately.

About Global Cancer Update Programme

World Cancer Research Fund International’s flagship Global Cancer Update Programme provides an analysis of international scientific research into how diet, nutrition, physical activity and weight affect cancer risk and survival. The programme is produced in partnership with American Institute for Cancer Research, World Cancer Research Fund in the UK and Wereld Kanker Onderzoek Fonds in The Netherlands.

As part of its development the Global Cancer Update Programme has built the largest cancer prevention database in the world, housed at Imperial College in London. It is the only authoritative scientific resource of its kind, is evaluated by an independent Panel of leading cancer experts and to date contains approximately 12,000 papers on cancer prevention and survival.

About World Cancer Research Fund International

World Cancer Research Fund International examines how diet, nutrition, body weight and physical activity affect your risk of developing and surviving cancer. As part of an international network of charities, we have been funding life-saving research, influencing global public health policy, and educating the public since 1982.

While society continues searching for a cure, our prevention and survival work is helping people live longer, happier, healthier lives – free from the devastating effects of cancer. www.wcrf.org and Twitter, Facebook, YouTube & LinkedIn.

About Imperial College London

Imperial College London is one of the world’s leading universities. The College’s 20,000 students and 8,000 staff are working to solve the biggest challenges in science, medicine, engineering and business.

Imperial is University of the Year 2022 in the Times and Sunday Times Good University Guide. It is the world’s fifth most international university, according to Times Higher Education, with academic ties to more than 150 countries. Reuters named the College as the UK’s most innovative university because of its exceptional entrepreneurial culture and ties to industry.

Imperial has a greater proportion of world-leading research than any other UK university, according to the Research Excellence Framework (REF). Imperial ranks first in the UK for research outputs, first in the UK for research environment, and first for research impact among Russell Group universities.