Nutrition transition in China--a challenge in the new millennium. (Editorial).

In recent decades, economic progress in fast developing countries has brought about demographic and epidemiological transitions. In addition, public health nutritionists have also witnessed the impact of economic growth on the transformation of dietary habits and nutritional status of these populations--nutrition transition. China is an outstanding example in this regard with its rapid economic development over the last 30 years. The successful agricultural and economic reforms as well as the continuing political stability since the late 1970s has led to a significant reduction in the number of people living under the poverty line. The sustainable food security system marked with stable food pricing and food provisions allows the nation's 1.26 billion population access to essential food items for health. Starvation is seldom seen in modern day China. The proportion of low birth weight infants (birth weight < 2.5 kg) has significantly decreased from 20 to 25% in 1982 to 4.2% in the late 1990s. The incidence of childhood chronic malnutrition has also declined in the country except in some rural mountainous areas such as Tibet where there are poor quality cultivated lands and the local people are still living in poverty.

The rapid economic performance as evident in a rising GDP in China has also brought about an increase in average family income. People can afford to enjoy more food variety, in particular animal foods and edible oils (mainly vegetable cooking oils) which were rationed and required to be purchased by using food stamps prior to the 1980s. Consequently, data from national dietary surveys and household food consumption surveys in the last 20 years have documented an accelerated increase in the consumption of meats, poultry, eggs and edible oils. Nowdays approximately 50% of the adult Chinese population has shifted towards an affluent diet high in fat content. There is also a tendency of shifting the use of staples from coarse grains such as sorghum, barley, rye, maize and millet to those of polished rice and wheat flour products in most parts of the country. In urban areas, the classic low fat, low meat and cereal-based diet is regarded as 'outdated poor-man's diet'. However, the consumption of fruits and vegetab les has been rising during the same period of time. The consumption of sugar and dairy products is still relatively low among Chinese people.

The percentage of dietary energy from fat intake has been doubled to 33% and the percentage of dietary energy from carbohydrate intake has been reduced from 72% to 53% in urban areas between 1978 and 1997, whereas the changes have been found less subtle in the rural communities with the percentage of dietary energy from fat intake increased from 10 to 25% and the percentage of dietary energy from carbohydrate intake increased by 19.5% to 62%. Recently, it has been found that energy intake has increased in the low income group and decreased in the high income group. However, the proportion of fat content has increased in both groups.

As a result of rapid industrialisation in some major cities of China, more than half of urban dwellers work in the office, service or manufacturing sectors in which the level of energy expenditure has dramatically reduced in comparison to the pre-industrialised agrarian economy. Together with increased utilisation of public transport and motor vehicles instead of pedalling bikes, rapid home electrification, preferences for sedentary leisure activities, and a shift in affluent dietary patterns, all these lifestyle factors link to a rapid escalation of BMI and lead to a greater risk of developing obesity among people in urban areas. In fact, the prevalence of obesity in Chinese men tripled while among Chinese women it doubled between 1989 and 1997. Using BMI of 25 to 30 to indicate those who are overweight, the proportion of Chinese people who are overweight (17.5%) is nowdays higher than those who have chronic under-nutrition (5.2%, BMI < 18.5). Among children and adolescents, there is a rising trend of being overweight rather than underweight in urban areas. However, there are slightly more children and adolescents who are underweight in rural areas of China. Obesity, a recognised risk factor for many diet related non-communicable diseases, is becoming an emerging public health problem in China. However, there is evidence to show that the BMI cut-off for overweight (BMI of 25) underestimates the health risk of being overweight among Chinese people. The use of BMI cut-off for assessing overweight and obesity in Chinese people needs to be redefined.

Epidemiological transition evolved in China and is also an outcome of economic progress and advancement of modern medicine, immunisation and hygiene. There is a shift from infectious diseases and malnutrition towards non-communicable diseases namely, cancers, hypertension, coronary artery disease and strokes. In 1995, 42% of deaths in-China were attributable to non-communicable diseases and the WHO has projected the proportion will increase to 52% by 2025. With the decline in the prevalence of communicable diseases, the health costs of under-nutrition will be reduced and the health care system will be burdened by the increasing prevalence of non-communicable diseases in the next 25 years.

China is a vast country with over 1.2 billion people. The rapid economic development of the country in the last 20 years mainly centres in the eastern coastal region provinces and cities such as Guangdong, Fujian, Shanghai, Jijiang, Jiangsu and Beijing. However, the economic development and living standards in the middle and western parts of the country are still lagging behind those in the eastern coastal region. The Chinese Authority in the new millennium has announced an ambitious economic development plan to develop the north-western part of the country in order to improve the economic performance, living standard of the local people and most importantly to alleviate poverty in this economically underdeveloped area. Therefore, nutrition transition in China as seen today is just a beginning of a lengthy process.

In human history, economic development is a powerful engine for driving human development, creation of wealth and alleviation of poverty. Western industrialised countries have already been through this similar painful process of a rise in mortality and morbidity resulting from industrial development, epidemiological and nutritional transitions. However, experience from these countries has shown that the prevalence of non-communicable chronic diseases can be significantly reduced through preventative measures and intervention including dietary modification and an adoption of a healthy lifestyle. Timely initiation of preventive measures and promotion of healthy lifestyle are of a paramount importance to curb the foreseeable rise in the mortality and morbidity of non-communicable diseases in developing countries undergoing transition.

The Chinese Authority realises that the co-existence of under-nutrition and over-nutrition in the country is a result of unsynchronised economic development across the country. In order to develop strategies to curb the co-existence of under-nutrition in certain rural areas and the ever increasing prevalence of diet-related affluent diseases in the urban areas of China, documents on food and nutrition policy were developed by the central government namely, 'National Plan of Action for Nutrition in China' in 1997, and 'Chinese Food and Nutrition Development Outline' in 2001. Highlights of some of the specific action plans to address the issue of prevention of over-nutrition and diet-related chronic diseases are listed below.

* Strengthening food and nutritional surveillance systems to monitor food security, food safety and nutritional status of the population.

* Encouragement of breastfeeding.

* Promotion of healthy school lunch program. By 2010, half of the school students in urban areas are to be provided with healthy school lunches.

* Strengthening professional nutrition and dietetic education in tertiary institutions, and expansion of training.

* Improvement of the status of dietitians.

* Gradual introduction of dietetic services to hospitals, kindergartens, schools and food catering establishments.

* Incorporation of basic nutrition education with fixed class hours into both the primary and secondary school curricula.

* Promotion of public nutrition education including healthy eating in the life cycle for the prevention of diet-related affluent diseases.

* Utilisation of the mass media to give nutrition messages to the general public.

* Promotion of low salt, low fat and low energy foods to the elderly.

To conclude this editorial, the remarks from Professor V. Ramalingaswami in his plenary speech addressing global perspectives on malnutrition at the 15th International Congress of Nutrition (Adelaide, Australia, 1993) are appropriate:

In nutrition, one sees a repetition of history in time and space. It would seem a wise policy to go back to some of the nutritionally sound and wholesome principles and practices in indigenous and traditional systems before they are lost in the avalanche of modernity.

Dr Warren T. K. Lee

Research Fellow

Department of Orthopaedics and Traumatology 

Faculty of Medicine

The Chinese University of Hong Kong