Keep a healthy weight to prevent cancer recurrence, U.S. report urges

Cancer survivors should try to keep from packing on the pounds because obesity increases the risk of the disease returning, the American Cancer Society said in its new guidelines Wednesday.

The recommendations update advice issued in 2001 and 2003.

Obesity is a known risk factor for some forms of cancer such as breast cancer in post-menopausal women, and cancers of the colon, esophagus, liver, gallbladder, pancreas, kidney, uterus and prostate.

There is also evidence that being overweight increases the risk of cancer recurring and reduces the chances of survival, the report said.

For some types of cancer, one to three hours of exercise weekly can reduce the risk of cancer recurrence and death, according to preliminary evidence cited in the report.

The report's authors also looked at the benefits of eating a vegetarian diet, which tend to be low in saturated fat and high in fibre and vitamins.

"However, no direct evidence has determined whether consuming a vegetarian diet has any additional benefit for the prevention of cancer recurrence over an omnivorous diet high in vegetables, fruits and whole grains, and low in red meats," they wrote.