Dietary transformation during social development: a case study of China

The observed fast increasing obesity rate and related health problems in urban China can be attributed to changing patterns of both diet and physical activity. This thesis focuses on the transformation of at-home dietary patterns and examines this against the background of concomitantly happening rapid social development. “Dietary pattern” is defined by six broad food groups. The three key aspects of social development discussed are the urbanisation process, the ageing population and supermarket revolution. “Community” is taken as the unit of analysis which is distinct from the extant studies that investigate individual, household or provincial level food choice. Thus, the impacts of both economic and social-transforming factors that underlie at-home diet decisions are examined through the food choice of communities. A Linearised Almost Ideal Demand System (LAIDS) model with a standard Tobit structure is adopted to capture the effects of social changes on at-home food choice, and Bayesian approach is followed in the estimation of the quantities of interest. Based on the estimated results, the ageing population and supermarket penetration are projected to their potential levels in 2050 urban China to investigate the potential impacts of their changes on diet. Findings confirm the differences in food demand between city and town areas. Contrary to the extant evidence, population ageing exhibits a significant negative effect on expenditure share of grains and a significant positive effect on that of less-commonly-eaten animal products. Such inconsistency could result from the interaction term between senior proportion and dietary knowledge included in the estimated demand model and the differently defined food groups. Supermarket penetration does not necessarily increase the expenditure share on snacks and drinks, and this fact also tends to be in contrary to most extant findings. This indicates that supermarket penetration may be linked to an overall lifestyle shift trend which does not necessarily have to be “unhealthy” in terms of its diet component for the overall community. The scenarios of 2050 with projected levels of supermarket penetration and population ageing are augmented by dietary knowledge. Estimates from augmented scenarios confirm the potential health outcomes of diet knowledge on food choice. With the goal of promoting vegetable and fruit consumption and reducing oil and sugar intake in the context of 2050 urban China, the scenario of increasing the convenience of modernised wet markets relative to supermarkets plus improving dietary knowledge could be the optimal choice