Using Oaxaca-Blinder Decomposition To Assess The Role Of Lifestyle Behaviors In Obesity Increase

With the growing share of older adults in the population and the rising prevalence of obesity among them, understanding the relative impact of contributing factors is crucial for explaining this trend and developing effective strategies to address this issue. PURPOSE: This study investigated the relative contributions of demographics and lifestyle behaviors in explaining differences between two continuous measures of obesity risk across two cycles of the National Health and Nutrition Examination Survey (NHANES). METHODS: A total of 1,461 participants aged 65 and older from the 2005-2006 and 2017-2018 NHANES cycles were analyzed using a two-fold Oaxaca-Blinder regression decomposition. Lifestyle behaviors were categorized into three groups: (1) diet, which included sugar intake, dietary fiber intake, saturated fatty acid intake, protein intake, and food consumed away from home; (2) physical activity, which was further divided into light, moderate, and vigorous intensities; and (3) other lifestyle factors, such as alcohol intake, smoking, sleep duration and quality, and intentional weight loss. Demographic factors included age, gender, ethnicity, education level, marital status, and annual family income. RESULTS: The decomposition analysis revealed that contributing factors explained nearly one-third (29.38%) of the overall increase in obesity (38.02%, p < 0.001) between the 2005-2006 and 2017-2018 periods. More than half of the changes in obesity during the 12-year study were attributed to lifestyle behaviors (54.86%), particularly diet (19.87%) and physical activity (9.00%). CONCLUSION: The significant role of lifestyle behaviors in the increase of obesity provides valuable evidence to guide future interventions aimed at promoting healthy aging and positively influencing obesity trends among older adults.