Although an obesity epidemic has spread to people of all age groups, empirical knowledge about elderly obesity remains largely scant, particularly in non-Western societies. This dissertation addresses that gap by examining the social determinants of overweight and obesity and weight gain among men and women, using 1999 and 2003 waves of the longitudinal Survey of Health and Living Status of the Near Elderly and Elderly in Taiwan. Existing literature shows that the effect of socioeconomic status (SES) on body weight shifts from positive to negative as the level of development of a society progresses from low to high, and social gradients in obesity appear first among women. A gender-specific pattern of social disparities in overweight and obesity is expected to have emerged in Taiwan.

The analysis captures a gendered pattern in the transition of the SES-obesity relationship in Taiwan. Similar to less-developed countries, men and women with more material resources (i.e. income and wealth) have an elevated risk of overweight and obesity, indicating the importance of material resources in getting access to food through most of the lifetime of this elderly population. However, household wealth is inversely associated with short-term weight gain among women, suggesting that wealth may become a protective factor against overweight and obesity.

The education effect has shifted to the pattern of Western societies, particularly among women. While education has strong negative impacts on cumulative body weight among women, it is inversely associated with short-term weight gain for both men and women. The protective effect of education emerges earlier among women than among men, probably as a result of educated women adopting the Western ideal of thinness. Also, the negative effect of childhood SES on body weight among women is transmitted through education. Hence, social disparities in overweight and obesity among older women is mainly produced by differential weight gains in adulthood for individuals of different SES.

Finally, the relationship between social participation and excess body weight is explored. Men and women with active social participation have a reduced risk for greater weight gain, suggesting that social participation may have some buffering effects on unhealthy weight outcomes of the disadvantaged groups, especially among women.