According to the World Cancer Research Fund and the American Institute for Cancer Research, excess body fat and red meat are linked to an increased risk of common cancers and should be avoided.

About 40 percent of all cancers are linked to food, lack of exercise, and body weight, the organizations said in a 571-page report released yesterday. A panel of 21 researchers who compiled the report said it was the most comprehensive evaluation ever of evidence linking personal habits to cancer risk.

The findings are meant to guide future scientific research, cancer prevention education programs, and health policy around the world, panelists said.

Hundreds of specialists evaluated more than 7,000 studies over five years to compile the report. Panelists found "convincing evidence" that carrying extra weight, particularly around the waist, may lead to cancer of the esophagus, pancreas, colon, kidney, and uterus, as well as postmenopausal breast cancer.

The panelists recommended keeping extra weight off, exercising at least 30 minutes a day, and limiting consumption of alcohol and high-fat foods, such as burgers, French fries, milk shakes, pastries, and sugary drinks. The guidelines also apply to cancer survivors, the report said.

Red meat, such as beef, pork, and lamb, which are linked to colorectal cancer, should be replaced with poultry, fish, and eggs. Processed meats that include bacon and lunchmeat should also be avoided, researchers said.

The causes of cancer are "extremely complex and involve factors like genetics, the environment, lifestyle, and a host of other issues," said Randy Huffman, vice president of scientific affairs at the Washington-based American Meat Institute, in a statement.