Bodyweight and risk of cancer statistics
This page presents information on bodyweight and cancer. Excess bodyweight is linked to risk of at least eight different types of cancer, and may affect risk of several other types.
There is convincing evidence that being overweight or obese increases cancer risk 1. A study published in December 2011 estimated that around 17,000 cases of cancer in the UK each year are linked to people being overweight or obese. The study notes that the list of cancers considered as being related to bodyweight in this study is conservative, so the actual number of cancers due to this factor may be higher.2
section reviewed 01/06/05
section updated 01/01/12
Table 2.1 summarises what we currently know about overweight, obesity and risk of cancer.
Body mass index (BMI) is the most commonly used measure of bodyweight. A BMI of 25-30 is overweight and a BMI of over 30 is obese.
The best evidence for a relationship between cancer and excess bodyweight is for cancers of the endometrium, kidney, oesophagus and gastric cardia (adenocarcinoma), colon, breast cancer in post-menopausal women, gallbladder and pancreas. Figure 2.1 shows the proportions of these cancers in the UK in 2010 caused by being overweight or obese. 2
Figure 2.1: Proportion of cancers linked to excess body mass index (BMI), UK, 2010
Obesity increases the risk of developing endometrial cancer by two to four-fold and the risk increases linearly with increases in BMI above 25. 3 Obesity also increases the risk of breast cancer in post-menopausal women by up to 30%. 4, 5,13By contrast, pre-menopausal women with a BMI of 31 or more have been shown to have a 46% reduced risk of breast cancer, compared with women whose BMI is less than 21. 5 This risk reduction may be because obesity can disrupt ovulation 6.
A likely mechanism for the increased risk for breast and endometrial cancer in overweight women is that fatty tissue alters the levels of sex steroids. In men and post-menopausal women, fatty tissue is a major site for synthesis of oestrogens. Obesity can also increase concentrations of oestradiol in the plasma by reducing levels of sex-hormone binding globulin caused by higher insulin production and insulin-like growth factor I activity. Breast cancer risk is also affected by age at menarche and height, both of which are influenced by bodyweight earlier in life 6.
The risk of colon cancer increases by about 25% in overweight men and by about 50% in obese men compared to men with a BMI under 25. 15. The link between overweight and colon cancer is weaker in women, with a meta-analysis showing a non-significant 9% increase in risk for obese women compared to women with a healthy bodyweight (BMI<25). 15. Central obesity may be a better indicator for colon cancer risk than BMI, with the European Prospective Investigation into Cancer and Nutrition showing similar risk increases in men and women, of up to 50%, for having a higher waist circumference or waist-to-hip ratio. 17 It has been shown that high levels of physical activity can reduce or remove the effect of obesity on the risk of colon cancer 7.
Risk of renal cell cancer increases by 24% in men and 34% in women with a 5-point increase in BMI, risk of oesophageal adenocarcinoma by approximately 50% in men and women and risk of gallbladder cancer by 59% in women, but not in men, for the same increase in BMI. 16
Two recent large prospective studies in America support an association between obesity and pancreatic cancer, and a meta-analysis showed a 19% risk increase for obese individuals. 9, 10,20. Other cancers that have been linked with BMI in at least one meta-analysis include non-Hodgkin lymphoma, thyroid, leukaemia, multiple myeloma and ovary. 13,16,19,21 Liver cancer has been linked with excess bodyweight in one meta-analysis,18 but not in another.16 Brain cancer has been linked with excess bodyweight in the Million Women Study.24
section reviewed 01/06/05
section updated 01/01/12
In the UK, the latest data show that a total of 69% of men and 59% of women have a BMI of 25 or more: this includes 24% of men and 32% of women who are obese. 12 In addition, 30% of boys and 31% of girls aged 2-18 in the UK are overweight or obese 12. The proportion of men and women in England with a BMI over 25 has increased since the 1990s, as Figure 2.2 shows. 23 The proportion of adults in Scotland that are overweight or obese has increased over the same period.25
It has been estimated, based on non-linear regression of trends in BMI in England between 1993-2004, that by 2050 60% of males and 50% of females in England will be obese. Based on the same analysis, it has been estimated that, by 2021, the proportion of overweight adult men in England will be equal to the proportion of obese men – around 43% in each group, while the proportion of men with a healthy bodyweight (BMI <25) will be 13%. For women, it has been estimated that the proportion of overweight and obese adults will be equal in 2024 (both 35%), while only a quarter of adult women will have a healthy BMI. 22
BMI is not a perfect measure of levels of overweight, especially for athletes, bodybuilders and children. However, trends in waist circumference in adults in England also show an increase in levels of overweight, as shown in Figure 2.3
section reviewed 01/06/05
section updated 01/06/11
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- World Health Organisation. Diet, Nutrition, and the Prevention of Chronic Disease: Report of a joint WHO/FAO expert consultation, in WHO Technical Report Series. Geneva: World Health Organisation/Food and Agriculture Organization; 2002.
- Parkin, D.M., Boyd, L. 8. Cancers attributable to overweight and obesity in the UK in 2010. Br J Cancer 2011; 105(S2):S34-S37.
- Bianchini F, Kaaks R, Vainio H. Overweight, obesity, and cancer risk. Lancet Oncol 2002; 3(9):565-74.
- Lahmann PH, Hoffmann K, Allen N, et al. Body size and breast cancer risk: Findings from the European prospective investigation into cancer and nutrition (EPIC). Int J Cancer 2004; 111(5):762-71.
- van den Brandt PA, Spiegelman D, Yaun SS, et al. Pooled analysis of prospective cohort studies on height, weight, and breast cancer risk. Am J Epidemiol 2000; 152(6):514-27.
- Key TJ, Schatzkin A, Willett WC, et al. Diet, nutrition and the prevention of cancer. Public Health Nutr 2004; 7(1A):187-200.
- Murphy TK, Calle EE, Rodriguez C, et al. Body mass index and colon cancer mortality in a large prospective study. Am J Epidemiol 2000; 152(9):847-54.
- Moore LL, Bradlee ML, Singer MR, et al. BMI and waist circumference as predictors of lifetime colon cancer risk in Framingham Study adults. Int J Obes Relat Metab Disord 2004; 28(4):559-67.
- Michaud DS, Giovannucci E, Willett WC, et al. Physical activity, obesity, height, and the risk of pancreatic cancer. JAMA 2001; 286(8):921-9.
- Patel AV, Rodriguez C, Bernstein L, et al. Obesity, recreational physical activity, and risk of pancreatic cancer in a large U.S. Cohort. Cancer Epidemiol Biomarkers Prev 2005; 14(2):459-66.
- The NHS Information Centre for Health and Social Care. Health Survey for England 2004: Updating of trend tables to include childhood obesity data. [Summary of key findings]. London: The NHS Information Centre for Health and Social Care; 2006.
- Department of Health/Food Standards Agency. National Diet and Nutrition Survey: headline results from year 1 (2008/09). PDF (416KB). London: Department of Health/Food Standards Agency.
- Reeves GK, Pirie K, Beral V, et al. Cancer incidence and mortality in relation to body mass index in the Million Women Study: cohort study. BMJ 2007; 335(7630):1134.
- Merry AH, Schouten LJ, Goldbohm RA, et al. Body mass index, height and risk of adenocarcinoma of the oesophagus and gastric cardia: a prospective cohort study. Gut 2007; 56(11):1503-11.
- Moghaddam AA, Woodward M, Huxley R. Obesity and Risk of Colorectal Cancer: A Meta-analysis of 31 Studies with 70,000 Events. Cancer Epidemiol Biomarkers Prev 2007; 16(12):2533-47.
- Renehan AG, Tyson M, Egger M, et al. Body-mass index and incidence of cancer: a systematic review and meta-analysis of prospective observational studies. Lancet 2008; 371:569-78.
- Pischon T, Lahmann PH, Boeing H, et al. Body size and risk of colon and rectal cancer in the European Prospective Investigation Into Cancer and Nutrition (EPIC). J Natl Cancer Inst 2006; 98(13):920-31.
- Larsson SC, Wolk A. Overweight, obesity and risk of liver cancer: a meta-analysis of cohort studies. Br J Cancer 2007; 97(7):1005-8.
- Schouten LJ, Rivera C, Hunter DJ, et al. Height, body mass index, and ovarian cancer: a pooled analysis of 12 cohort studies. Cancer Epidemiol Biomarkers Prev 2008; 17(4):902-12.
- Berrington de Gonzalez A, Sweetland S, Spencer E. A meta-analysis of obesity and the risk of pancreatic cancer. Br J Cancer 2003; 89(3):519-23.
- Leitzmann MF, Koebnick C, Danforth KN, et al. Body mass index and risk of ovarian cancer. Cancer 2009; 115:812-22.
- McPherson K, Marsh T, Brown M. Tackling obesities: Future choices -- Modelling future trends in obesity and the impact on health. 2nd Edition. 2007.
- The Health and Social Care Information Centre, 2011 Health Survey for England - 2009 trend tables. London: The Health and Social Care Information Centre; 2011.
- Benson VS, Pirie K, Green J, et al. Lifestyle factors and primary glioma and meningioma tumours in the Million Women Study cohort. Br J Cancer 2008; 99(1):185-90.
- The Scottish Government. The Scottish Health Survey 2010. Volume One: Main Report. Edinburgh: The Scottish Government; 2011.