Half of all cases of womb cancer and a type of oesophageal cancer in women are caused by being overweight or obese, according to a new report published online in the British Medical Journal today (Wednesday).

This study provides the first reliable evidence on the relevance of being overweight or obese for a wide range of cancers in women in the UK today.

Its findings suggest that among middle aged and older women in the UK, around five percent of all cancers, that is 6000 cancers each year, are caused by being overweight or obese.

As well as pinpointing womb cancer and one type of oesophageal cancer as examples where being overweight or obese is a major risk factor, the study also finds that excess weight increases the risk of kidney cancer, leukaemia, multiple myeloma, pancreatic cancer, non-Hodgkin’s lymphoma, ovarian cancer and, in some age-groups, breast and bowel cancer.

The Million Women Study, funded by Cancer Research UK, is the biggest study ever undertaken to look at women and cancer risk. Over one million UK women were studied during seven years. More than 45,000 cases of cancer and 17,000 cancer deaths occurred during that time.

Lead researcher Dr Gillian Reeves, Cancer Research UK epidemiologist based at Oxford University, said: “Based on our findings, we estimate that being overweight or obese accounts for around 6,000 out of a total 120,000 new cases of cancer each year among middle-aged and older women in the UK.

“Our research also shows that being overweight has a much bigger impact on the risk of some cancers than others. Two thirds of the additional 6000 cancers each year due to overweight or obesity would be cancers of the womb or breast.”

But the research found that the relationship between body mass index (BMI)* and cancer also depended on a woman’s stage of life. For example, being overweight increases the risk of breast cancer only after the menopause and the risk of bowel cancer only before the menopause.

Sara Hiom, director of Cancer Research UK’s health information, said: “This research adds to the evidence regarding the impact of being overweight or obese on developing cancer and dying from the disease.

“While most people readily associate carrying extra weight with being a general health risk, many do not make a specific link with cancer. These findings need to be taken into consideration alongside the established strong relationships between body fatness and other common illnesses such as diabetes and heart attacks.”


For media enquiries contact the Cancer Research UK press office on 020 7061 8300, or the duty press officer, out of hours, on 07050 264059


There are more than 44,000 cases of breast cancer diagnosed in the UK each year. More than 6,000 women are diagnosed with endometrial cancer and around 2,700 women are diagnosed with oesophageal cancer each year.

*Women with a BMI of 25-29 were defined as “overweight” and women with a BMI of 30 or more as “obese” in accordance with the World Heath Organisation’s criteria.

Calculate your BMI on the NHS Direct website.

Ten Top Tips to help achieve and maintain a healthy body weight

The tips are simple habits that everyone can permanently fit into their daily routines. Keeping up all ten tips in the long term will help you lose weight and keep it off.

  1. Keep to your meal routine. Try to eat at roughly the same times each day, whether this is two or five times a day.
  2. Go reduced fat. Choose reduced fat versions of foods such as dairy products, spreads and salad dressings where you can. Use them sparingly as some can still be high in fat.
  3. Walk off the weight. Walk 10,000 steps (about 60-90 minutes of moderate activity) each day. You can use a pedometer to help count the steps. You can break up your walking over the day.
  4. Pack a healthy snack. If you snack, choose a healthy option such as fresh fruit or low calorie yogurts instead of chocolate or crisps.
  5. Look at the labels. Be careful about food claims. Check the fat and sugar content on food labels when shopping and preparing food.
  6. Caution with your portions. Don’t heap food on your plate (except vegetables). Think twice before having second helpings.
  7. Up on your feet. Break up your sitting time. Stand up for ten minutes out of every hour.
  8. Think about your drinks. Choose water or sugar-free squashes. Unsweetened fruit juice contains natural sugar so limit it to 1 glass per day (200ml / 1/3 pint). Alcohol is high in calories; try to limit the amount you drink.
  9. Focus on your food. Slow down. Don’t eat on the go or while watching TV. Eat at a table if possible.
  10. Don’t forget your 5 a day. Eat at least five portions of fruit and vegetables a day (400g in total).

About Cancer Research UK

  • Together with its partners and supporters, Cancer Research UK’s vision is to beat cancer.
  • Cancer Research UK carries out world-class research to improve understanding of the disease and find out how to prevent, diagnose and treat different kinds of cancer.
  • Cancer Research UK ensures that its findings are used to improve the lives of all cancer patients.
  • Cancer Research UK helps people to understand cancer, the progress that is being made and the choices each person can make.
  • Cancer Research UK works in partnership with others to achieve the greatest impact in the global fight against cancer.
  • For further information about Cancer Research UK’s work or to find out how to support the charity, please call 020 7009 8820 or visit our homepage.