Dietary intake data

Dietary intake survey data provide a more precise measure of the food consumption habits of households and individuals. These data can be used to look at differences in consumption by such characteristics as income, gender and place of residence.

Most of the dietary intake data from the case study countries come from nationally representative surveys that use a variety of methodologies and capture different age groups. Although it is not appropriate to compare these data with data from FAOSTAT, trends from both could be expected to go in the same direction, but this is not always the case.

Trends in dietary energy intake

Nearly all the case study countries show a trend towards declining energy intake (measured as kilocalories [kcal] per capita per day) (Table 5). This pattern has also been observed in other developing countries, leading to debate over the seemingly paradoxical increase in overweight and obesity at lower reported dietary energy intakes (Stubbs and Lee, 2004; Heini and Weinsier, 1999; Prentice and Jebb, 1995). The declining trend in dietary energy intake also contrasts with FAOSTAT data on total dietary energy availability. The real picture of what is happening appears to lie somewhere in between.

Some researchers support their intake data with the theory that there have been large declines in energy expenditure. Thus, increasing overweight is possible even at lower intakes because there is a greater energy imbalance (India case study). Others conclude that the declining trend reflects problems with data collection and the well-documented tendency of underreporting and systematic bias in intake measures, with heavier persons consistently underreporting more frequently than individuals of normal weight (Mexico case study; Livingstone and Black, 2003).

Both of these explanations may be true. Underreporting of energy intake is one of the major limitations of dietary intake studies (Livingstone and Black, 2003). At the same time, energy expenditures have fallen dramatically as a result of the modernization of agriculture and the increased use of motor vehicles, computers and labour-saving technologies. Recent evidence from the United States, where obesity rates have risen from 15 to 31 percent, has reversed the idea of the "American paradox" in which reported energy intakes were falling while obesity rates climbed. Reports for recent years show increases in reported energy intakes for both men and women (MMWR Weekly, 2004).

These findings highlight a need for better dietary intake instruments and training of the staff who carry out dietary intake studies, as well as a critical need for more and better information on energy expenditure. Information on energy expenditure is not routinely included in most national-level surveys. However, if energy expenditure is believed to be a major factor in rising obesity and risk of NCD, measurement instruments and collection of energy expenditure data need to be improved and supported.

TABLE 5
Trends in dietary energy intake from household surveys

Energy density of the diet

One apparently consistent trend is that of increased energy density of diets. The percentage of energy derived from fat has increased in all the case study countries, especially China where it rose by nearly 10 percent over the past decade. The highest percentage of dietary energy from fat (31 percent) is in Mexico, and the lowest in India (14 percent). The low meat consumption in India is a likely explanation for this low figure.

TABLE 6
Trends in percentage of dietary energy from fat

Trends in dietary intake by food group

FAOSTAT data are used to show changes in food intake in much of the initial work on the occurrence of a nutrition transition in developing countries (Popkin, 1994). There is fairly good concordance between commodity trends using FAOSTAT data and trends in consumption of different food groups using dietary intake data.

The five case study countries for which trend data on dietary intake by food group are available show much the same pattern of dietary changes. The main trends observed from intake data are:

• decreasing intakes of cereals, roots and tubers;
• decreasing intakes of legumes, nuts and seeds (except in China);
• no change or an increase in intakes of edible fats and oils;
• large increases in intakes of fish, meat and poultry (except in India);
• increasing intakes of sugars and sweets;

• increasing intakes of fruits and vegetables (except in rural China and the Philippines).

The adverse effects of the observed patterns of dietary change, including the increases in saturated fat, cholesterol and dietary energy density, have been the subject of much recent literature, while the positive effects have largely been overlooked. Transition from a predominantly cereal-based diet to one that includes more meat and dairy products should have a positive impact on the intakes of high-quality protein and several micronutrients. In particular, intakes of vitamin A and iron, two of the most widespread micronutrient deficiencies worldwide, should show improvement.

The crossover from beneficial to detrimental is experienced when intakes of commodities (sugar, alcohol) or dietary components (saturated fat, salt) reach levels known to create disease risk factors. These levels have been reviewed recently in the WHO/FAO report on diet, nutrition and the prevention of chronic disease, which forms the basis for the population nutrient intake goals listed in Table 7 (WHO/FAO, 2003). The Philippines case study highlights the beneficial effects of the dietary changes, which are reflected by an increased proportion of people consuming the recommended percentages of energy from carbohydrates and fat. However, decreasing consumption of fruits and vegetables in the Philippines and China is reflected in lower percentages of the population with recommended intakes of these commodities (Table 7).

TABLE 7
Trends in achievement of population nutrient intake goals

The impact of changes in dietary patterns on micronutrient intake

Given the increasing intake of animal source foods, and in some countries the increased intake of fruits and vegetables, a trend towards improved intakes of micronutrients (particularly iron and vitamin A) could be expected. Data from Mexico, China and the Philippines indicate that there is a marginal positive trend towards increased consumption of iron in the diets of children (Table 8). Intakes of vitamin A also increased for children in the Philippines and China, while vitamin C intake decreased slightly in China but increased in the Philippines.

In the Philippines, adult intake of vitamin A has increased, but intakes of iron and vitamin C have not shown any change. In Mexico, adult intake of vitamin A has increased, but intake of iron has decreased.

The trends among children are encouraging, and indicate that dietary changes are having a positive impact on micronutrient intakes. Changes among adults are less dramatic, and do not indicate much of a positive trend, except in the case of vitamin A. Given the large increase in meat, fish and poultry consumption, an improvement in the iron intake of adults could be expected, but this is not observed. This seemingly contradictory pattern could be the result of:

• changes in consumption patterns within animal source foods - the Philippines consumes more pork, which has lower iron content than beef;

• revisions in food composition tables - again in the Philippines, where the tables now include more processed and canned fish products, which contain less iron than the values used previously.

Trends in nutritional anthropometry and micronutrient deficiencies among children and adults

Caution is needed regarding inter-country comparisons of data related to trends in nutritional anthropometry and micronutrient status of adults and children, because years, age groups and cut-off points may not be consistent. An effort was made to document such differences among the countries.

Trends in the nutritional status of children

Some progress in reducing child undernutrition has been achieved in all of the case study countries. The differing biological significance of anthropometric indicators of child growth is an important consideration in the current analysis. Stunting is a deficit in gain in length/height caused by deficits of a chronic nature. Wasting reflects short-term deprivation. Underweight is a combination of the two indicators, and has been termed "overall malnutrition". In situations of improving food security and improvements in health, water and sanitation, wasting prevalence should decrease rapidly. Stunting prevalence will be slower to improve, as the indicator is cumulative of past deprivation. Prevalence of underweight will usually decline at a faster rate than that of stunting.

China’s progress between 1992 and 2000 has been the most rapid of the case study countries, with rates of stunting falling by 55 percent, from 31 to 14 percent, prevalence of underweight declining 42 percent, from 17.4 to 10 percent, and wasting decreasing by 35 percent, from 3.4 to 2.2 percent. Progress has been slower in all the other countries, with prevalence rates of stunting declining 38 percent in Egypt, 13 percent in the Philippines and 22 percent in Mexico (calculation of percentage changes was not possible for India and South Africa because of differences in age groups). Reductions in the prevalence of underweight have been faster, with reductions of more than 30 percent in Egypt and Mexico, but only 5 percent in the Philippines. Wasting prevalence is now very low in Mexico and Egypt, but has increased in the Philippines from 5.6 to 6.5 percent.

The Center for Disease Control classifies rates of stunting of more than 30 percent, underweight of more than 20 percent and wasting of more than 10 percent as high prevalence (Epi-info Manual), indicating the level of public health significance. In India, all three nutritional anthropometric measures are still at high levels. In the Philippines, stunting and underweight are classified as high, while wasting has fallen to less than 10 percent. In the other case study countries, prevalence levels of stunting, underweight and wasting are classified as medium or low, at least at the nationally aggregated level. Nationally aggregated data hide disparities within regions and among different ethnic and socio-economic groups. For example, in poor, rural areas of China, stunting prevalence is 29 percent. In Mexico, it is more than 30 percent for children aged one to four years in rural areas, the south region and the lowest socio-economic bracket. Clearly, child growth remains an important public health problem.

The use of resources to ensure appropriate foetal and early child growth is justified, not only by the direct cost of undernutrition in terms of loss of life and diminished mental and physical potential, but also by more recent evidence of links between suboptimal foetal and early child growth and later problems with NCDs, particularly cardiovascular disease (CVD), type-2 diabetes and hypertension (Delisle, 2002).

Overweight in children is an emerging concern in many of the case study countries. In Egypt, prevalence of overweight among children is higher than prevalence of underweight and stunting, signalling an urgent need for Egypt to develop strategies to address this new problem. Increasing rates of overweight and obesity in children signal a very alarming trend. Half of the children who are obese at six years of age will go on to become obese adults (Georgetown University Center for Aging, 2002). Obesity is a risk factor for a range of chronic health problems, including type-2 diabetes, coronary heart disease, hypertension and some types of cancers (WHO, 1997). Early onset of obesity confers higher risk of developing these obesity-related chronic diseases.

TABLE 9
Trends in child anthropometry

¹ Oversampling of low socio-economic groups
Source: WHO Global Database on Child Growth.

Trends in nutritional status of adults

The prevalences of under- and overweight among adults are strikingly different from those of children (Table 10). Overweight is more prevalent than underweight in adults in China, Egypt, Mexico and the Philippines. Overweight prevalence has been increasing in all countries, while underweight is on the decline.

Data presented at the national level hide large disparities in prevalence rates among regions and socio-economic classes. For example, in India, 23.5 percent of women 15 to 45 years of age living in urban areas have a body mass index (BMI) ³ 25, and in Delhi more than 40 percent of women have a BMI above 25. In the highest socio-economic classes, obesity rates of more than 50 percent for females and 32 percent for males have been reported (Shetty, 2002). In Mexico, there are important differences between northern and southern regions; 31 percent of adults living in the north are obese (BMI > 30), compared with 24 percent in the south.

TABLE 10
Trends in adult anthropometry

Micronutrient deficiencies

In addition to the double burden of under- and overnutrition, which is demonstrated principally in differences in the prevalence of undernutrition among preschool children and of overweight in adults, many of the case study countries continue to have high prevalence rates of micronutrient deficiencies. Approximately one-third of women and children in China and the Philippines are anaemic, and a staggering 90 percent of women and children in India are diagnosed with anaemia (Table 11). Persistently high levels of anaemia in the Philippines are attributed to poor child feeding and weaning practices and poor compliance with iron supplementation programmes (Philippines case study). In India, the dietary intakes of iron and folate are low, and there are high rates of blood loss from malaria and parasitic infections (India case study).

TABLE 11
Prevalence of anaemia in women and children (last available year)

Large percentages of the populations in the case study countries are also suffering from vitamin A deficiency (VAD). Few countries have trend data for VAD, but the Philippines recorded a higher prevalence of children with VAD in 2003 compared with ten years earlier. VAD among children in China differs according to residence. The prevalence of low serum retinol among children aged three to 12 years is 3.0 percent in urban and 11.2 percent in rural areas.

TABLE 12
Prevalence of vitamin A deficiency¹ in children and adults

¹ Serum retinol < 20 µg/dl.

Burden of disease

Although the classic definition of the double burden of malnutrition is concerned primarily with the dual burden of over- and undernutrition, it is also useful to examine morbidity and mortality trends given the close links among disease, disability and under- and overnutrition.

Disability-adjusted life years (DALYs) report on the time lived with a disability and the time lost because of premature mortality. Globally, the proportion of DALYs lost to NCD has been increasing, while DALYs from communicable disease, including nutritional disorders, are declining (Figure 3).

FIGURE 3
Trends in DALYs by disease category

In its annual publication State of the world’s health, the World Health Organization (WHO) reports data on DALYs from specific diseases by region and mortality stratum (Table 14). The double burden of disease is most clearly evident in the proportional DALYs of the Southeast Asia and Eastern Mediterranean regions, with high DALYs lost from both communicable and non-communicable diseases. The regions of the Americas and Western Pacific are moving away from high levels of communicable disease, while malaria, HIV and respiratory infection remain high in the Africa region.

TABLE 13
DALYs lost from communicable and non-communicable diseases and injuries

Data estimates from 2002. Africa: high child/very high adult mortality stratum; Americas: low child/low adult mortality stratum; Southeast Asia: high child/high adult mortality stratum; Eastern Mediterranean: high child/high adult mortality stratum; Western Pacific: low child/low adult mortality stratum.

Source: WHO. World Health Report 2004. Geneva.

NCDs and NCD risk factors

In addition to obesity, diabetes, CVD and some cancers are also related to diet and lifestyle (WHO/FAO, 2003), as are certain risk factors including high blood pressure, increased cholesterol and elevated blood sugar.

For most of the case study countries, monitoring the incidence and prevalence of NCDs and associated risk factors is relatively new, so examination of trends is not possible. Some of the case study countries do not yet have nationally representative monitoring systems in place, and data on the magnitude of the problem of NCDs have to be inferred from various small studies.

In the four case studies with data, more than 20 percent of adults have high blood pressure, a risk factor for CVD. In Egypt and Mexico, prevalence of diabetes is nearly 10 percent (Table 14). In China, prevalence rates of diabetes in people over 60 years of age reach as high as 17 percent.

TABLE 14
Prevalence of hypertension and diabetes

Physical activity

Trend data on physical activity are weak or non-existent in most of the case study countries. China is the exception, and has information from 1989 to 2000 on light, moderate and heavy physical activity. The data show a 20 percent decrease in people reporting heavy activity and a 46 percent increase in people reporting light physical activity.

Double burden of malnutrition

The data presented in this section clearly demonstrate that most countries in the study are struggling to some degree with the double burden of malnutrition. The countries were classified into the following three typologies based on predominant health and nutrition problems.

Typology one: (India and the Philippines)

• High prevalence of undernutrition in both children and adults.
• Emerging problems of overnutrition, diabetes and high blood pressure, mainly in urban areas.

• High prevalence of micronutrient deficiencies.

• Stunting at levels of public health significance, but declining underweight and wasting.
• In adults, overweight/obesity more of a problem than underweight.
• Rising incidence of NCD, particularly CVD, diabetes and cancer.
• Rise in some infectious diseases, notably TB and HIV.

• High prevalence of micronutrient deficiencies.

• Both stunting and overweight appear as public health problems in children.
• Low prevalence of underweight and wasting in children.
• Underweight in adults no longer of public health significance, but prevalence of overweight high and/or rapidly increasing.
• Iron and vitamin A deficiencies remain public health problems.

• Diabetes and coronary heart disease are increasing, while infectious disease is decreasing (although certain diseases such as TB and HIV remain high in China and Egypt).

The different typologies suggest that country programmes should focus on different areas. For example, in India and the Philippines, reducing child and adult undernutrition and micronutrient deficiencies should remain a top priority, and efforts to limit the rise of overweight/obesity and diet-related chronic diseases should be initiated. In Egypt, Mexico and, to a lesser degree, China and South Africa, overweight and obesity among adults is already widespread and the problem is becoming more significant among children. In these countries, in addition to prevention efforts, more focus needs to be directed to early detection and treatment.

Conclusions

Noticeable changes in dietary patterns have occurred in all of the case study countries; these changes have not necessarily corresponded to increased intakes of total dietary energy, but have corresponded to increased fat content of diets. The most striking changes have been increases in pork, poultry and beef, sugar and sweet products, and - in most countries - fats and oils.

Some of the dietary changes have brought welcome improvements to nutritional status, contributing to reduced child undernutrition and improved micronutrient intake in some countries. However, the combination of an energy-dense diet with low physical activity has contributed to an increasing prevalence of overweight adults. This pattern will probably continue, given that current economic and social trends are conducive to widespread changes in lifestyle.

Although some progress has been made in reducing undernutrition of children, national and regional efforts to improve child growth need to continue and should not be overshadowed by the need to address NCD among adults. It is worth bearing in mind the continuing evidence generated by the Barker hypothesis, which links undernutrition in foetal and early life to greater risk of NCD in adulthood.

Dietary and lifestyle choices, including food choice, smoking, physical inactivity and alcohol consumption, are some of the most strikingly modifiable risk factors. The challenge is to develop effective programmes and policies aimed at both prevention and control. Developed countries have attempted to tackle these problems for many years, but with little success. Ideally, strategies that are effective in ameliorating both under- and overnutrition should be identified and developed. In the shorter term, priority should be given to preventive action by addressing undernutrition of infants, children and pregnant women, thereby circumventing the risks predicted by the Barker hypothesis.

References

Barker, D.J.P. 2004. The developmental origins of adult disease. Journal of the American College of Nutrition, 23(6): 588S-595S.

Chopra, M. 2004a. From apartheid to globalization: Health and social change in South Africa. Hygiea Internationalis, 4(1): 153-174.

Chopra, M. 2004b. Globalization, urbanization and nutritional changes in South Africa. In FAO. Globalization of food systems in developing countries: impact on food security and nutrition, pp.119-133. FAO Food and Nutrition Paper No. 83. Rome, FAO.

Cook, I. & Dummer, T. 2003. Changing health in China: re-evaluating the epidemiological transition model. Health Policy, 67: 329-343.

Delisle, H. 2002. Programming of chronic disease by impaired foetal nutrition. Evidence and implications for policy and intervention strategies. WHO/NHD/02.3. Geneva, WHO Department of Nutrition for Health and Development.

Delisle, H. 2005. Early nutritional influences on obesity, diabetes and cardiovascular disease risk. International Workshop, 6-9 June 2004, Montreal University, Quebec, Canada. Maternal and Child Nutrition, 1(3), 128-129.

Development Policy Review. 2003. Issue September/November 2003.

FAO. 2004. Globalization of food systems in developing countries: impact on food security and nutrition. FAO Food and Nutrition Paper No. 83. Rome.

Georgetown University Center on Aging. 2002. Childhood obesity. A lifelong threat to health. Data profile March 2002. Institute for Health Care Research and Policy, Georgetown University. Available at: http://hpi.georgetown.edu/agingsociety/pdfs/obesity.pdf.

Gillespie, S. & Haddad, L. 2003. The double burden of malnutrition in Asia. Causes, consequences and solutions. Washington, DC, International Food Policy Research Institute. Sage Publications. pp. 236.

Heini, A. & Weinsier, R. 1997. Divergent trends in obesity and fat intake patterns: the American paradox. The American Journal of Medicine, 102: 259-264.

Kitange, H. The worst of two worlds. Adult mortality in Tanzania. Available at: www.id21.org/zinter/id21zinter.exe?a=0&i=insightshealth%231art3&u=41fe3e16

Livingstone, M.B. & Black, A. 2003. Markers of the validity of reported energy intake. Journal of Nutrition, 133: S895-S920.

Mendez, M., Du, S. & Popkin, B. 2004. Urbanization, income and the nutrition transition in China: a case study. In FAO. Globalization of food systems in developing countries: impact on food security and nutrition, pp.169-194. Rome, FAO.

Mendez, M. & Popkin, B. 2004. Globalization, urbanization and nutritional change in the developing world. In FAO. Globalization of food systems in developing countries: impact on food security and nutrition, pp.55-80. FAO Food and Nutrition Paper No. 83. Rome, FAO.

MMWR Weekly. 2004. Trends in intake of energy and macronutrients in the United States, 1971-2000. MMWR weekly, 53(04): 80-82.

Popkin, B. 1994. The nutrition transition in low-income countries: an emerging crisis. Nutrition Reviews, 52(9).

Popkin, B. 2002. The shift in stages of the nutrition transition in the developing world differs from past experiences. Public Health Nutrition, 5(1A): 205-214.

Popkin, B. 2003. The nutrition transition in the developing world. Development Policy Review, 21(5-6): 581-597.

Prentice, A. & Jebb, S. 1995. Obesity in Britain: Gluttony or sloth? British Medical Journal, 311: 437-439.

Public Health Nutrition. 2002. Volume 1(A), 2002.

Sawaya, A., Martins, P. & Martins, V. 2004. Impact of globalization on food consumption, health and nutrition in urban areas: a case study of Brazil. In FAO. Globalization of food systems in developing countries: impact on food security and nutrition, pp. 253-274. FAO Food and Nutrition Paper No. 83. Rome, FAO.

Shetty, P. 2002. Nutrition transition in India. Public Health Nutrition, 5(1A): 175-182.

Shetty, P. & Gopalan, C., eds. 1998. Diet, nutrition and chronic disease: an Asian perspective. London, Smith-Gordon and Co.

Shetty P. & McPherson, K., eds. 1997. Diet, nutrition and chronic disease: Lessons from contrasting worlds. Chichester, UK, John Wiley and Sons.

Stubbs, C. & Lee, A. 2004. The obesity epidemic: both energy intake and physical activity contribute. Medical Journal of Australia, 181(9): 489-491.

UNDP. 2004. Human Development Report, 2004. Cultural liberty in today’s diverse world? New York, United Nations Development Programme (UNDP). Available at: http://hdr.undp.org/reports/global/2004/.

UN Millennium Project. 2005. Halving hunger: It can be done. Task Force on Hunger. London, Earthscan.

WHO. 1997. Obesity - preventing and managing the global epidemic. Report of a WHO Consultation on Obesity. Geneva.

WHO. 2002. World Health Report 2002. Reducing risks, promoting healthy life. Geneva.

WHO/FAO. 2003. Diet, nutrition and the prevention of chronic diseases. Report of a Joint WHO/FAO expert consultation. WHO Technical Report Series No. 916. Geneva, WHO.

World Cancer Research Fund. 1997. Food nutrition and the prevention of cancer: a global perspective. Washington, DC, American Institute for Cancer Research.