Obesity is strongly linked to several of the most common cancers in the US.
But a new survey finds most Americans are not aware of the risk.
"This is critically important because, in the next few years, obesity will replace tobacco as the leading modifiable risk factor for cancer," says Dr. Clifford Hudis, the CEO of the American Society of Clinical Oncology.
The survey from the American Society of Clinical Oncology finds less than a third of people understand large amounts of excess weight contribute to 13 different types of cancer including the breast, colon, and prostate.
Alcohol is another cancer risk factor correctly identified by only about a third of respondents. Less than a quarter surveyed are aware that viruses can cause tumors.
Nearly all cases of cervical cancer and a growing number of head and neck tumors are a direct result of human papillomavirus.
"On the other hand, there are some factors that people are worried about, and maybe they shouldn't be so much," says Dr. Clifford Hudis, the CEO of the American Society of Clinical Oncology.
Of the 4,016 people surveyed, 14% thought cell phones cause cancer and 8% incorrectly thought caffeine causes cancer.
There is plenty of evidence to suggest Americans should give more weight to cancer's link to obesity.
More than 70-percent of US adults are overweight or obese, greatly increasing their odds of developing tumors.