US Adults Fall Short of the Dietary Guidelines for Cancer Prevention Regardless of BMI Category

Abstract

BackgroundCancer risk is determined by specific factors, including body weight and dietary patterns. Accordingly, the World Cancer Research Fund/American Institute for Cancer Research published updated cancer prevention recommendations in 2018 based on comprehensive reviews of modifiable behaviors associated with cancer risk. ObjectiveThe objective of this study was to determine the extent to which US adults meet these evidence-based recommendations and how adherence differs by weight status. DesignThis was a cross-sectional study using nationally representative data from the 2005-2016 National Health and Nutrition Examination Survey (NHANES). Participants/settingDietary intake data for 30,888 adults 18 years and older with normal body mass index (BMI), overweight, or obesity were analyzed. Main outcome measuresDifferences in dietary intakes and the proportion of adults meeting guidelines were compared across BMI categories. Statistical analyses performedLogistic regression and 1-way analysis of covariance were used to analyze differences in adherence to recommendations, controlling for age, sex, race/ethnicity, and family income as a percent of the federal poverty rate. ResultsRegarding fruit and nonstarchy vegetables, 62.8% of adults with normal BMI, 64.5% with overweight, and 70.1% with obesity fell short of recommendations. Regarding whole grains, 67.9% of adults with normal BMI, 70.2% with overweight, and 73.1% with obesity did not meet the recommendation. Regarding red meat, 36.7% of adults with normal BMI, 41.6% with overweight, and 43.5% with obesity consumed >18 oz/week, with a significant difference in mean intakes between adults with normal BMI and obesity (P < .001). Adults with obesity consumed significantly less dietary fiber and more processed meat than adults with normal BMI and overweight (P < 0.001). ConclusionsFew U.S. adults meet cancer prevention recommendations; adults with obesity are significantly less likely to do so. Future research should evaluate compounded risk resulting from obesity and poor dietary patterns inconsistent with current evidence-based guidelines, and inform targeted interventions to address these issues.