BMI, CANCER RISK PERCEPTION, AND PREVENTIVE BELIEFS

Purpose: To examine differences in cancer risk perception and preventive cancer beliefs by body mass index (BMI).

Method: We used the 2007 Health Information National Trends Survey random digit dialed data. These data include 3104 (unweighted) responses (from 4092 total) for those who report never having been diagnosed with cancer and who provided information on BMI. We used frequencies and weighted percentages to explore associations between BMI categories of obese (30+), overweight (25-<30), and normal/underweight (<25) by perceived likelihood of getting cancer (somewhat/very high vs somewhat/very low/moderate), frequency of cancer worry (often/all the time vs sometimes/rarely/never), agreement cancer is caused by lifestyle (strong/somewhat agreement vs strong/somewhat disagreement), and  agreement there is not much you can do to lower cancer chances (strong/somewhat agreement vs strong/somewhat disagreement).

Result: Those overweight and obese were slightly more likely than those normal/underweight to think they had a high chance of developing cancer (18% vs 14%; p<0.0001)). Obese respondents were more likely than other BMI groups to worry often/all the time about getting cancer (10% vs 5-6%; p<0.0001). Among obese individuals, 65% classified themselves as being overweight; 25% believe a lot that obesity is inherited. BMI groups did not vary in: reporting the percentage who felt physical activity or exercise decreases the chances of getting some types of cancer (62-64%); agreement that cancer is most often caused by a person’s behavior or lifestyle (49-51%); or agreement that there’s not much you can do to lower your chances of getting cancer (25-26%). There was no difference across BMI groups in modifiable behavior beliefs (12-14%), defined as those who agreed there’s not much you can do to lower cancer chances, and disagreed that cancer is most often caused by a person’s behavior.

Conclusion: Healthy lifestyle has been associated with the reduction in risk of certain cancers. Overweight and particularly obese persons are more likely to report worry or perceive a high chance of getting cancer, but do not appear to have internalized the potential for modifiable lifestyle changes that might reduce their risk. Educating overweight and particularly obese individuals about their ability to potentially reduce their cancer risk may help motivate uptake of a healthy lifestyle.