Feb. 26, 2009 -- About a third of common adult cancers may be preventable in the U.S. -- and that doesn't even count cancers that could be prevented by not smoking.

That's according to a new report from the World Cancer Research Fund (WCRF) and its sister organization, the American Institute for Cancer Research (AICR).

In the new report, the WCRF and AICR estimate that in the U.S., eating a nutritious diet, being physically active, and keeping body fat under control may prevent:

38% of breast cancers

45% of colorectal cancers

36% of lung cancers

39% of pancreatic cancers

47% of stomach cancers

69% of esophageal cancers

63% of cancers of the mouth, pharynx, or larynx

70% of endometrial cancers

24% of kidney cancers

21% of gallbladder cancers

15% of liver cancers

11% of prostate cancers

Diet, physical activity, and limited body fat could prevent 34% of those 12 cancers overall in the U.S., and 24% of all cancers, according to the report.

Those estimates are all about the big picture -- the effect on the overall population -- not an individual's chance of developing cancer.

The WCRF/AICR report also includes tips for governments, industries, school, media, and other institutions worldwide to promote healthy lifestyles. Among those recommendations:

New developments should be designed to encourage walking and cycling.

Government and school cafeterias should provide healthy foods and drinks.

Food and drink industries should price healthy fare competitively with other products and stop promoting sugary drinks and unhealthy foods to kids.

Workplaces should have policies and environments that are supportive of breastfeeding.

Media should promote cancer prevention and flag misleading cancer claims.

That guidance is in line with the American Cancer Society's recommendation for community action, notes Colleen Doyle, the American Cancer Society's director of nutrition and physical activity. "Reversing the obesity epidemic will require bold action and multiple strategies, including policy changes at national, state, and local levels that make it easier for people to eat better and be more active," Doyle says in an American Cancer Society statement.

The WCRF/AICR, which has previously published cancer prevention tips for individuals, stresses that cancer prevention means trimming the odds of developing cancer, not totally eliminating cancer.

Many factors affect cancer risk, and some of them -- like family history -- aren't within your control. A healthy lifestyle doesn't wipe out cancer risk -- but it also has no downside. And, because early detection is often a big help in treating cancer when it does occur, check with your doctor about routine cancer screening tests.