Nutrition/Obesity
The modifying role of fruit and vegetable intake and physical activity in obesity and chronic disease associations Muskan Ahuja* Muskan Ahuja Ahuja Ahuja Ahuja Ahuja Department of Epidemiology, University of Nebraska Medical Center, Omaha, NE
Obesity affects 40% of U.S. adults and is associated with increased risks for a variety of chronic diseases. We examined the relationship between self-reported body mass index (BMI) and chronic diseases and assessed effect modification by fruit and vegetable intake and physical activity. We analyzed cross-sectional data from the Behavioral Risk Factor Surveillance System for 2017, 2019, and 2021 (all U.S. states and DC, n = 1,306,916 adults). BMI was calculated from self-reported height and weight and categorized as underweight, normal weight (reference), overweight, and obesity. Participants reported whether they have ever been diagnosed with certain chronic diseases, including diabetes (type I/II), hypertension, coronary artery disease (CAD), myocardial infarction, stroke, and depression. We created a counter outcome variable (0, 1, or ≥2 diseases) to assess multimorbidity. Risk differences (RDs) were estimated using weighted modified Poisson regression, adjusting for sociodemographic and socioeconomic factors, and key health behaviors such as smoking, alcohol, fruit and vegetable intake, and physical activity. Effect modification was assessed using four strata combining fruit and vegetable intake (≥5 vs <5 servings/day) and physical activity (any vs none). Compared with normal weight, obesity was associated with excess risk for all outcomes, with the strongest associations for hypertension (RD = 181.6 per 1,000), diabetes (RD = 116.3), and depression (RD = 72.4). Obesity was also associated with 345 excess cases of ≥2 chronic diseases per 1,000 adults. In stratified analysis, obesity associations with diabetes, CAD, stroke, depression, and multimorbidity were weaker among adults with high fruit and vegetable intake, any physical activity, or both. These findings add to the existing body of literature suggesting that improved diet and physical activity may reduce chronic disease burden among adults with obesity, though longitudinal and trial studies are needed.