Prospective study on nutrition transition in China

Transcription

1 Prospective study on nutrition transition in China Fengying Zhai, Huijun Wang, Shufa Du, Yuna He, Zhihong Wang, Keyou Ge, and Barry M Popkin The aim of the prospective study reported here was to examine the effects of social and economic transformation on dietary patterns and nutritional status in China. The study began in 1989 and continued with follow-ups in 1991, 1993, 1997, 2, and 24. A total of subjects aged 18 4 years from 428 households in nine provinces were included. Weighed records and three consecutive 24-h recalls were used. Over the study period, average consumption of all animal foods except milk increased, while cereal intake decreased. The proportion of animal protein and fat as a percentage of energy also increased. However, vitamin A and calcium intake did not increase and remained low. Child height and weight increased while undernutrition decreased and overweight increased. The results indicate that rapid changes in dietary pattern are associated with economic reforms in China. 29 International Life Sciences Institute INTRODUCTION Twenty-five years ago, China introduced sweeping reforms in the structure of its rural economy. The economy has experienced exponential growth in the past decade, with per-capita GDP rising from 46 yuan in 198 to 91 yuan in Since 199, the annual rate of per-capita GDP growth has been 8.6%. 2 A rapid rise in economic productivity has resulted in continuing increases in income and changes in the traditional Chinese diet. But these changes are occurring at markedly different rates across the country. Following rapid economic and social change, the pace of nutrition transition has accelerated in China. 3,4 The study presented here focused on the interplay of demographic and economic changes that affect food demand and nutritional status in China s population. Data and study population SUBJECT AND METHODS The data was derived from the China Economic, Population, Nutrition and Health Survey, which covers nine provinces that vary substantially in geography, economic development, public resources, and health indicators. A multistage, random cluster sample was used to draw the sample surveyed in each of the provinces. In there were 19 primary sampling units; a new province and its sampling units were added in Currently, there are about 38 households in the overall survey, covering 16, individuals, including all age groups. The surveys collected information on all individuals living in the household. A complete household roster was used as a reference for subsequent blocks of questions on individual, household, and community infrastructure. The study included adults aged 18 4 years in the survey to comprise the study population (Table 1). Trends in dietary intake RESULTS Over the past years, adult intake of cereals and starchy roots declined. During the same period, consumption of animal food, especially meat and eggs, increased (Table 2). The proportion of dietary energy derived from fat in the adult diet increased dramatically, from 19% to 28%, mainly due to replacement of calories from Affiliations: F Zhai, H Wang, SDu, YHe, Z Wang, and KGeare with the Institute of Nutrition and Food Safety, China CDC, Beijing, China. BM Popkin is with the Carolina Population Center, University of North Carolina at Chapel Hill, North Carolina, USA. Correspondence: F Zhai, Institute of Nutrition and Food Safety, China CDC, No. 29 Nan Wei Road, Xuan Wu District, Beijing, China. zhai@infh.ac.cn. Key words: China Health and Nutrition Survey, dietary pattern, nutrition transition, trends S6 doi:.1111/j x

2 Table 1 Composition of the study population in China by year. Population group n % n % n % n % n % n % Sex Male Female Total Age Total Community Urban Suburb Town Rural Total carbohydrate (Figure 1). About one-half of dietary fat was derived from edible oil, while the consumption of refined animal fat decreased. Comparing the surveys from 1989 and 24 revealed that energy and protein intake had decreased over time, but the quantity of protein had increased as a percentage of total calories. The average calcium intake among the city and suburban populations was only about 43 mg per day, while among the town and village populations, the average calcium intake was about 38 mg per day. Intake of vitamins and other minerals remained steady (Table 3). Trends in nutritional status Trends in the nutritional status of the Chinese population clearly demonstrate that undernutrition is declining rapidly, while overweight and obesity are increasing in both children and adults. Moreover, the rate of overweight increase is becoming increasingly rapid (Figure 2). The distribution of BMI estimated from this survey in 1989, 1997, 2, and 24 is shown in Figures 3 and 4 and the line of BMI shifted to the right in both males and females. Thus, the proportion to the right of the distribution has increased with time. If action is not taken, the prevalence of overweight and obesity will increase more rapidly than before. DISCUSSION Over the past 2 years, the status of diet and nutrition among the urban and rural populations in China has undergone significant improvement, and the prevalence of malnutrition and nutrition deficiencies has been decreasing continuously. 7 However, China is also 24 2 Year protein fat carbonhydrates % 2% 4% 6% 8% % Figure 1 Trends in percent of macronutrients as proportion of total dietary energy intake in the Chinese population. S7

3 Table 2 Trends in intake (g/day) of food groups for adults in China by residence and year. Food Total Rural Urban Rice Wheat Other cereals Tubers Legumes and products Vegetables* Fresh fruit Pork Other meats Poultry Milk and products Eggs and products Fish Vegetable oil Animal fat Cakes Sugar Salt Pastes and soy sauce Other foods * Total vegetables; excludes potatoes. Products containing milk. Products in which egg is the key ingredient. All processed meats. S8

4 Table 3 Nutrient intake by community and year in China. Community Year No. of subjects Nutrient Energy Protein Calcium Iron Zinc Retinol Thiamin Riboflavin Niacin Ascorbic acid (MJ) (g) (mg) (mg) (mg) (RE) (mg) (mg) (mg) (mg) City Suburb Town Village Total S9

5 A percent (%) rural underweight urban underweight rural overweight urban overweight B 3 male underweight male overweight female underweight female overweight 2 2 percent (%) Figure 2 Trends in under- and overnutrition in adults in China by urban and rural residence (A) and gender (B). undergoing a remarkably fast, but undesirable, shift towards a stage of nutrition transition dominated by a high intake of fat and animal foods, as well as a high prevalence of diet-related non-communicable diseases such as obesity, diabetes mellitus, cardiovascular disease, and cancer. The classic Chinese diet includes cereals and vegetables with few animal foods. 8 Itisadietthatmany scholars consider as extremely healthy when adequate levels of intake are achieved. With the presently prosperous economy, the quality of the average diet of the Chinese people has improved significantly. The energy and protein intakes among the urban and rural populations have, on the whole, been satisfactory; the consumption of meat, poultry, eggs, and other animal products has increased significantly and the percentage of 2 Percent(%) BMI Figure 3 Changes in distribution of adult male BMI in China. S6

6 2 Percent (%) BMI Figure 4 Changes in distribution of adult female BMI in China. good-quality protein in the diet has also increased. However, to a certain extent, the dietary pattern among urban residents is not so exemplary. The level of meat and oil consumption is too high, and cereal consumption is at a relatively low level. Low-level consumption of dairy and soy products remains a common problem in China. High dietary energy, high dietary fat, and less physical activity are closely related to the occurrence of overweight, obesity, diabetes, and abnormal blood lipid levels; high salt intake is associated with the risk of hypertension. It should be particularly emphasized that subjects who had higher levels of fat intake and lower levels of physical activity were at highest risk for the above-mentioned chronic diseases. 9, CONCLUSION In conclusion, China is undergoing a remarkable, but undesirable, rapid transition towards a stage of nutrition transition characterized by high rates of diet-related noncommunicable diseases in a very short time. China is facing simultaneous challenges of under- and overnutrition. On the one hand, the government s efforts in the past decades to reduce undernutrition have been very successful and the prevalence of stunted and underweight children has decreased significantly. On the other hand, the prevalence of overweight and obesity and the morbidity associated with noncommunicable diseases have increased significantly in the past 2 years. 11,12 In the same time period, the burden of chronic noncommunicable diseases in China has also become greater. Acknowledgment Declaration of interest. The authors have no relevant interests to declare. REFERENCES 1. National Bureau of Statistics of P.R. China. Chinese Statistical Yearbook. Beijing: China Statistics Press; Statistics Division. Statistical Indicators for Asia and the Pacific. Vol. XXXIV: 24. Bangkok: United Nations Economic and Social Commission for Asia and the Pacific; Du S, Lu B, Zhai F, Popkin BM. A new stage of the nutrition transition in China. Public Health Nutr. 22;: Zhai F, Wang H, Du S, Ge K, Popkin BM. The changing trend of dietary pattern of Chinese population: an eight provinces case study in China. Acta Nutrimenta Sinica. 22;24:6.. Popkin BM, Horton S, Kim S, Mahal A, Shuigao J. Trends in diet, nutritional status, and diet-related noncommunicable diseases in China and India: the economic costs of the nutrition transition. Nutr Rev. 21;9: Zhai F, Wang H, Chang S, Fu D, Ge K, Popkin BM. The current status, trend, and influencing factors to malnutrition of infants and children in China. J Community Nutr. 24;6: Zhai F, Fu D, Du S, Ge K, Chen C, Popkin BM. What is China doing in policy-making to push back the negative aspects of the nutrition transition? Public Health Nutr. 22;: Du S, Mroz TA, Zhai F, Popkin BM. Rapid income growth adversely affects diet quality in China particularly for the poor! Soc Sci Med. 24;9: Bell AC, Ge K, Popkin BM. The road to obesity or the path to prevention: motorized transportation and obesity in China. Obes Res. 22;: Stookey JD. Energy density, energy intake and weight status in a large free-living sample of Chinese adults: exploring the underlying roles of fat, protein, carbohydrate, fiber and water intakes. Eur J Clin Nutr. 21;: Wang Y, Monteiro C, Popkin BM. Trends of obesity and underweight in older children and adolescents in the United States, Brazil, China, and Russia. Am J Clin Nutr. 22;7: Wang H, Zhai F, He G, Du S, Hao H. Trends in overweight among Chinese adult in some provinces from 1989 to 2. Acta Nutrimenta Sinica. 24;26: S61