Introduction

China is a developing world with more than 1.1 billion people, accounting for about 22% of the world's total population, but occupying only 7% of the world's arable land. The per capita food availability has fluctuated over the past 40 years since 1949, when the People's Republic of China was founded (State Statistic Yearbook, 1991). With the rapid development of the economy since 1978, there was a marked improvement in the per capita income and food consumption of the people. Food patterns have also changed in the 1980s (Ge, Chen & Shen, 1991; Popkin et al., 1993). During this decade China conquered problems of food scarcity at the national level and has undergone a remarkable dietary transition. In order to examine the changes in diet and nutritional status, two large-scale surveys were conducted in the 1980s. One was the nationwide nutrition survey in 1982 (CNS-82), which consisted of a dietary survey, anthropometric measurements, clinical examinations and biochemical assays; the other was the 1989 China Health and Nutrition Survey (CHNS-89), which collected detailed social, economic and ecological information in addition to biological data.

The International Dietary Energy Consultancy Group proposed the use of body mass index (BMI: kg/m²) for specifying chronic energy deficiency (CED) in adults, and cut-off points were identified for its classification (James, Ferro-Luzzi & Waterlow, 1988). For assessing nutritional status, the BMI of Chinese adults was examined based on the CNS-82 and CHNS-89 data and the distribution of BMI was linked with some dietary and social economic factors. The main results and the* possible significance are discussed in this paper.