Understanding the nutrition transition: measuring rapid dietary changes in transitional countries.

OBJECTIVE To understand methodological concerns related to dietary intake collection in transitional societies. DESIGN Three days of household weighing and measurement of all food used and repeated 24-hour recalls. SETTING Eight Chinese provinces. SUBJECTS Five thousand nine hundred and fifty-two and 5152 adults aged 20-45 years in 1989 and 1997, respectively. RESULTS Great variance exists in the types and quantity of animal products used in common recipes. For example, the proportion of pork from lean cuts in 'stir-fried fresh pepper and pork' varies between 14 and 24% in urban and rural areas and the total pork content for 100 g (dish) varies by 15 to 19 g between rural and urban areas in each of eight provinces. Another challenge relates to the variation in the edible vegetable oil content added during food preparation. Reliance on standard recipes for each fried dish would miss the variations in oil use over time, space and socio-economic status. CONCLUSIONS Dietary change is rapid in transitional countries. Reliance on recipes standardised for animal food and edible oil contents will lead to very large systematic errors in the measurement of energy, fat and protein intakes.