[Differences in diet intake frequency of adults: findings from half a million people in 10 areas in China].

Objective: To describe the differences in diet intake frequency of adults in 10 areas surveyed by China Kadoorie Biobank (CKB) project.
Methods: CKB project recruited voluntary residents aged 30-79 years from 5 urban areas and 5 rural areas in China. The baseline survey was conducted among 512 891 eligible subjects during 2004-2008. The intake frequencies of 12 food groups were assessed through in-person interviews and analyzed. The results were adjusted for age and sex structure of the study population.
Results: Rice was the main cereal consumed every day in urban areas (99.0%) and rural areas (99.9%) in southern China, while wheat was the main cereal consumed every day in rural areas (99.0%) and Qingdao (88.4%) in northern China. Most subjects in Henan (98.8%) consumed other staple food every day. The lowest proportion of daily intake of fresh vegetables was observed in Gansu (74.0%) . In both southern and northern areas, urban subjects had higher proportions of daily intakes of fresh fruits, preserved vegetables, and meat than rural subjects. Similar results were found when comparing the proportions of intakes of poultry and fish/seafood at least 1 day every week. Contrast to southern China (urban: 6.5%, rural: 6.9%) , the proportions of daily intake of fresh eggs were higher in both urban areas (37.1%) and rural areas (14.6%) in northern China. The highest proportions of daily intake of soybean products and dairy products were observed in Harbin (10.0%) and Qingdao (34.3%).
Conclusion: The intake of cereal, fresh eggs and soybean products differed between the south and the north of China. The intake of meat, poultry, fish/seafood, fresh fruits, preserved vegetables and dairy products varied considerably between urban areas and rural areas.