The researchers compiled data from 141 studies and considered the impact of weight on 15 cancer sites on more diverse populations than had been done previously. The research covered more than 280,000 cases from North America, Europe, Australia and Asia.
Increased weight was most strongly linked to an increased risk for cancer of the esophagus in men and women and for endometrial and gallbladder cancers in women.
The study also found a link between obesity and the risk for more common malignancies such as postmenopausal breast cancer in women, colon cancer in men, and blood cancer in both sexes.
However, being overweight was not associated with an increase in risk for prostate cancer in men, premenopausal breast cancer and ovarian cancer in women, and lung cancer in men and women.
Researchers tracked their subjects for about nine to 15 years for their body mass index, or BMI, a calculation based on weight and height, and correlating it with incidents of cancer.
BMI is a numerical measure of fatness based on a person's weight relative to height. A BMI of 18.5 to below 25 is considered normal weight, while 25 to just under 30 is considered overweight, but not obese. Someone is considered obese if they have a BMI of 30 or above.
In men, an average weight gain of 33 pounds increased the risk of esophageal cancer by 52 percent, thyroid cancer by 33 percent, and colon and kidney cancers each by 24 percent, the research found.
In women, a weight gain of 29 pounds increased the risk of cancer in the uterus and gall bladder by nearly 60 percent, esophagus by 51 percent and kidney by 34 percent, the study said.
The new study, published Friday in the journal Lancet, suggests it could also increase chances for cancer of the esophagus, thyroid, kidney, uterus and gall bladder, among others.
