Increased body mass index may have more happiness, life satisfaction, and self-rated health in the aging process: A 10-year longitudinal study

Understanding intricate relationships among various determinants of overall well-being is crucial for promoting healthy aging. The body mass index (BMI), happiness, life satisfaction, and self-rated health are key indicators of well-being in older adults. However, the dynamic interplay among these factors and the BMI was previously unclear. This study aimed to investigate longitudinal associations between the BMI and happiness, life satisfaction, and self-rated health. The study design was a 10-year longitudinal study. Data were retrieved from the database of the Panel Study of Family Dynamics, Taiwan. In total, 1298 participants with a mean age of 64.71 years at the time of the first wave served as the main sample for the secondary data analysis. Parallel latent growth modeling was performed to assess relationships between the BMI and various indicators over time. Results for all participants showed that the intercept of the BMI was positively associated with the intercepts of happiness (β=0.260, p = 0.038) and life satisfaction (β=0.274, p = 0.021) and negatively associated with the intercept of self-rated health (β=-0.145, p = 0.041). The slope of the BMI was positively associated with the slopes of happiness (β=0.003, p = 0.036), life satisfaction (β=0.005, p < 0.001), and self-rated health (β=0.002, p = 0.007). All indices suggested a satisfactory model fit. These findings suggested that a slight increase in the BMI may be beneficial for the well-being of older adults, leading to a happier, healthier, and more satisfying later life.