We did an exhaustive Medline search of scientific publications between 1966 and 2000, which formed the basis of a recent panel discussion by an international expert group convened by the International Agency for Research on Cancer, in Lyon, France.38 We selected studies on the basis of the number of cases included—at least 200 cases for breast and colorectal cancers; 100 cases for colon adenomas, endometrial, and prostate cancers; and 50 cases for cancers at other organ sites. Only those
ReviewOverweight, obesity, and cancer risk
Section snippets
Methods for assessing obesity
An individual's BMI is defined as their weight in kilograms divided by the square of their height in metres; it is generally used as an indirect measure of adiposity in epidemiological studies. ‘Normal weight’ is classified as BMI between 18·5 and 25 kg/m2, ‘overweight’ is over 25 kg/m2, and ‘obesity’ is defined as a BMI of greater than 30 kg/m2.13 Although BMI does not distinguish directly between adipose tissue and lean body masses, there is a good correlation between BMI and the percentage
Adiposity and cancer risk
In this review, relative risks (RRs) are given for the highest versus the lowest categories of BMI (Figure 2, Figure 3, Figure 4, Figure 5). BMI ranges differed between cancer sites and between studies, but on average the ranges were:
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<22 kg/m2 and >28·5 kg/m2 for colon and breast cancer,
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<23·5 kg/m2 and >30 kg/m2 for endo-metrial cancer.
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<22·5 kg/m2 and >27 kg/m2 for kidney and prostate cancer, and
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<21·5 kg/m2 and >25 kg/m2 for oeso-phageal cancer.
Case-control and prospective cohort studies
Mechanisms of altered cancer risk
The relation between excess body weight and cancer risk suggests that excess energy is an important risk factor for development of cancer. This notion is supported by experimental observations that energy restriction can confer a strong protection against the development of several types of tumours in different species.40, 41, 42, 43 Furthermore, there is evidence that individuals who take regular physical activity are protected against cancers of the breast, colon, and possibly the endometrium.
Weight control and physical activity
Avoidance of weight gain should become one of the mainstays of chronic disease prevention in modern societies. Weight control can be achieved by changes in energy intake and by increased physical activity. About half of the adult population of industrialised countries are insufficiently active in their leisure time and one quarter to one third can be classified as totally inactive.38 Promotion of physical activity seems particularly effective for prevention of weight gain,79 but results are
Conclusions
There is sufficient evidence that adiposity can cause cancers of the colon, breast (in postmenopausal women), endometrium, kidney, oesophagus, and gastric cardia. Furthermore, plausible mechanistic explanations exist for most of these associations. Nevertheless, uncertainties remain about the extent of excess weight that constitutes an increase in cancer risk. For prevention of diabetes and cardiovascular disease, a BMI in the range 18·5–25 kg/m2 has been recommended. The breadth of this range
Search strategy and selection criteria
References (79)
- et al.
Association between teen-age obesity and cancer in 56 111 women: all cancers and endometrial carcinoma.
Prev Med
(1976) - et al.
Body weight: estimation of risk for breast and endometrial cancers.
Am J Clin Nutr
(1996) - et al.
Height and weight at various ages and risk of breast cancer.
Ann Epidemiol
(1992) - et al.
Protection of DNA damage by dietary restriction.
Free Radic Biol Med
(1992) - et al.
Effects of aging and caloric restriction on hepatic drug metabolizing enzymes in the Fischer 344 rat. II: Effects on conjugating enzymes.
Mech Ageing Dev
(1989) - et al.
Effects of caloric restriction on rodent drug and carcinogen metabolizing enzymes: implications for mutagenesis and cancer.
Mutat Res
(1993) - et al.
Regulation of proliferation, invasion and growth factor synthesis in breast cancer by steroids.
J Steroid Biochem Mol Biol
(1990) - et al.
Pathophysiology of sex hormone binding globulin (SHBG): relation to insulin.
J Steroid Biochem Mol Biol
(1991) Adipose tissue as a source of hormones.
Am J Clin Nutr
(1987)- et al.
Circulating concentrations of insulin-like growth factor-I and risk of breast cancer.
Lancet
(1998)
Incidence, increasing prevalence, and predictors of change in obesity and fat distribution over 5 years in the rapidly developing population of Mauritius
Int J Obes Relat Metab Disord
Overweight and obesity in the United States: prevalence and trends, 1960–1994.
Int J Obes Relat Metab Disord
The epidemiology of obesity
Shifting obesity trends in Brazil.
Eur J Clin Nutr
Global prevalence and secular trends in obesity
Obesity in women from developing countries.
Eur J Clin Nutr
The continuing epidemics of obesity and diabetes in the United States.
JAMA
Prevalence and trends of obesity in the Netherlands 1987–1991.
Int J Obes Relat Metab Disord
Trends in cardiovascular risk factors in Australia: results from the National Heart Foundation's Risk Factor Prevalence Study, 1980–1989.
Med J Aust
WWW publications from the WHO MONICA project
Overweight, obesity, and health risk
Arch Intern Med
Energy and protein requirements: report of a joint expert consultation
WHO TR 724
Body-mass index as a measure of body fatness: age- and sex-specific prediction formulas.
Br J Nutr
Body size and the risk of colon cancer in a large case-control study.
Int J Obes Relat Metab Disord
Diet, body mass and colorectal cancer: a case-referent study in Stockholm.
Int J Cancer
Leisure-time physical activity, body size, and colon cancer in women. Nurses' Health Study Research Group.
J Natl Cancer Inst
Obesity and colorectal adenomatous polyps.
J Natl Cancer Inst
Physical activity, obesity, and risk of colorectal adenoma in women (United States).
Cancer Causes Control
Obesity, weight gain, large weight changes, and adenomatous polyps of the left colon and rectum.
Am J Epidemiol
Associations of sedentary lifestyle, obesity, smoking, alcohol use, and diabetes with the risk of colorectal cancer.
Cancer Res
The association of body size and large bowel cancer risk in Wisconsin (United States) women.
Cancer Causes Control
Obesity, weight gain and risk of colon adenomas in Japanese men.
Jpn J Cancer Res
A prospective study in general practice on breast-cancer risk in postmenopausal women.
Int J Cancer
Combined effects of body size, parity, and menstrual events on breast cancer incidence in seven countries.
Am J Epidemiol
Diet, body size, and breast cancer.
Epidemiol Rev
Dual effects of weight and weight gain on breast cancer risk.
JAMA
Body size in different periods of life and breast cancer risk in post-menopausal women.
Int J Cancer
Breast cancer and hormone replacement therapy: collaborative reanalysis of data from 51 epidemiological studies of 52 705 women with breast cancer and 108 411 women without breast cancer
Lancet
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