Association Between Obesity and Education Level Among the Elderly in Taipei, Taiwan

The aging population in Taiwan, particularly in Taipei, is rapidly increasing, transforming it into an aged society. Concurrently, obesity prevalence has nearly tripled globally since 1975, with Taiwan experiencing a similar rise, including among the elderly. Geriatric obesity is a serious public health concern associated with increased mortality and numerous chronic diseases. While prior research has established a link between obesity and education levels in various countries, focusing on elderly populations remains limited. This study addresses this gap by exploring the association between obesity and education level among the elderly in Taipei, Taiwan, considering other demographic factors like age, race, income, and smoking status.

Existing literature demonstrates an inverse association between obesity and education level in many developed countries. Studies in the US, Canada, Australia, and England show lower obesity prevalence among college graduates. However, results from Korea indicate a positive association in men but an inverse association in women. Previous Taiwanese studies have also shown an inverse relationship between obesity and education in women and a correlation between morbid obesity and low socioeconomic status (SES). Limited research has focused on obesity among elderly populations, with one study suggesting a 5-9% reduction in the likelihood of obesity for each additional year of education among the elderly in Japan and the US. The need for identifying risk factors associated with geriatric obesity is crucial due to its increasing financial burden on healthcare.

This cross-sectional study analyzed data from Taipei's elderly health examination program (2013-2015). The program's participants (≥65 years, or ≥55 years for aborigines) underwent physical examinations, including height and weight measurements. Obesity was defined as BMI ≥27 kg/m² (Taiwan's standard). Data included sex, age, race, income status, smoking status, and education level (categorized into years of education). Multivariate logistic regression analyzed the association between education level and obesity after controlling for confounding factors. Subgroup analyses were conducted based on data collection year and age group (≤70, 71-80, >80 years). The study received ethical approval and informed consent was waived due to minimal risk and de-identified data.

The final analysis included 28,092 men and 31,835 women. Obesity prevalence increased as years of education decreased, significantly so for both sexes. Compared to those with ≥16 years of education, men with ≤6 years of education had 1.44 times higher odds of obesity, while women had 2.28 times higher odds. This inverse association was more pronounced among women. Aboriginal participants had considerably higher obesity rates (men: 43.7%, women: 38.3%) compared to non-aboriginal participants. Current smoking showed a negative correlation with obesity in men but not women. Income status did not significantly affect obesity rates. Subgroup analyses by year and age group confirmed the inverse association between education and obesity. Younger age groups showed a higher prevalence of obesity across all education levels, suggesting a cohort effect related to improved nutritional intake rather than age alone.

This study confirms the inverse association between education level and obesity among the elderly in Taipei, mirroring findings from other developed nations. The stronger trend among women might reflect societal factors influencing women's educational attainment and lifestyle choices. The higher obesity rates among aborigines suggest the influence of sociocultural factors beyond education and income. The lower odds of obesity among older smoking men requires careful interpretation, considering the overall health risks associated with smoking. The study's limitations include its cross-sectional design, which prevents establishing causality, and potential selection bias due to the nature of the data source. The higher participation rate of higher-educated individuals in the health examination program may affect the generalizability of the findings.

This study establishes a correlation between lower education levels and higher obesity prevalence among elderly individuals in Taipei. The inverse association was more pronounced in women, and aboriginal ethnicity was a significant factor in obesity prevalence. Future longitudinal studies with quasi-experimental designs are needed to determine causality. Targeted public health programs addressing dietary habits, physical activity, and access to healthy food are essential for improving health outcomes, particularly among disadvantaged groups with lower education and SES.

The cross-sectional design limits causal inference. Selection bias may exist due to the study relying on participants in the elderly health examination program, possibly over-representing those with higher education and health consciousness. The limited income status categories and the small proportion of lower-income participants may have restricted the ability to analyze the effect of income status on obesity. The data may not represent the entire elderly population in Taiwan.