Mixed
Higher body-mass index (BMI) is associated with significantly increased mortality rates from all cancers combined and from multiple specific cancer sites, with the highest risks observed in individuals with a BMI of 40 or greater.
Maintaining a BMI in the normal range (18.5-24.9) is one of the most effective ways to reduce your risk of dying from cancer. The risk of cancer death increases steadily as BMI increases, with those having a BMI of 40 or higher facing more than a 50% higher risk of cancer death compared to those of normal weight. This applies to both men and women and covers many specific cancer types.
The heaviest members of this cohort (those with a body-mass index [the weight in kilograms divided by the square of the height in meters] of at least 40) had death rates from all cancers combined that were 52 percent higher (for men) and 62 percent higher (for women) than the rates in men and women of normal weight.
Why this rating
Large prospective cohort (n>900,000), long follow-up (16 years), rigorous statistical adjustment for confounders.
Source
Overweight, Obesity, and Mortality from Cancer in a Prospectively Studied Cohort of U.S. Adults
Eugenia E. Calle et al. · New England Journal of Medicine · 2003
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