Dimension of the Nutritional Problem in the World

International organisations (UNO, FAO, WHO, UNICEF, World Bank) have established methods of evaluating available foods, the consumption of food, and nutritional status by taking into consideration parameters of agricultural production, anthropometrical measurements, birth-rate, mortality and morbidity rates, and clinical, immunolog-ical, haematological, and biochemical parameters.

One of the most frequently used comprehensive indexes of alimentary and nutritional condi tion is the DES (dietary energy supply). The DES expresses the daily average of available energy per person, taking into account all the alimentary sources of a country during a certain period. However, because of the unequal distribution of available food among social classes, age groups, and those with special physiological needs (pregnancy, childhood, old age, and illness), the DES underestimates the real alimentary needs.

DES tables are produced by the FAO based on food balance sheets (FBS), which track the supply and use of food worldwide but do not indicate actual consumption or equity in the distribution of available supplies. Nevertheless, trends in food and energy supplies at the national and regional levels are well-expressed by the FBS. Accordingly, the diets of 800 million people lack 100-400 kcal per day, but most of these people are not dying of starvation; they become thin but are not emaciated (Fig. 1).

Evidence of chronic hunger is not always apparent because the body compensates by slowing down metabolism and physical activity. In children, growth and school activity are compromised, susceptibility to disease is increased.

Mothers may give birth to underweight babies. The situation is particularly serious in sub-Saharan Africa, where acute malnutrition occurs more often, while the majority of chronically hungry people is in Asia and the Pacific area.

In 46% of countries, the undernourished have an average deficit of more than 300 kcal/ person/day, including deficits in every nutrient, particularly the starchy staple foods (carbohydrate-rich maize, potatoes, rice, wheat, and cassava) that usually provide the greatest part of energy. About 11 countries have a DES that is less than 2000 kcal per person. While some people generally get enough of the staple foods, they lack other foods, including legumes, meat, fish, oils, dairy products, vegetables, and fruit, which provide protein, fat, micronutrients, and energy.

The global availability of food in the world has increased in the last few years, except in the poorest developing countries, including the subSahara, which is afflicted by frequent famine for climatic and social reasons. About 18 million inhabitants of these regions seriously risk starving to death.

Moreover, 60% of the world population con

Percent of countries

Percent of countries

Kcal/person/day
Fig. 1. Average food deficit in the world

sumes about 2600 Kcal per person per day, which is considered barely sufficient for limited activity. In 41 developing countries, food intake is more than 2600 Kcal per day per person, while in 15 countries it is more than 3000 Kcal/inhabitant per day. In 11 countries, the DES is less than 2000 Kcal/person/per day, resulting in the inevitable development of severe malnutrition (Table 4).

To identify the groups and individuals who are most affected by denutrition within a population, methods have been established that estimate chronic alimentary defects and long-term needs, with reference to basal metabolism and during working activity. The FAO World Food Survey has fixed the new limit of the minimum alimentary need at 1.54 times the basal metabolic rate (BMR), previously 1.2-1.4 times the BMR. The earlier value expressed a person's energy expenditure before meals and at complete rest, whereas the more recent index corresponds, in a more realistic manner, to the energy level required to maintain body weight and carry out light physical activity. Raising the value of the minimum amount of energy needed automatically increases the number of undernourished people in the world. Malnutrition, both under and over, can no longer be addressed without considering global food insecurity; socioeconomic disparity, both globally and nationally; and global cultural, social, and epidemiological transitions. The economic dispar-

ity between more and less affluent countries is growing. At the same time, the income gap is growing within most countries, both developed and developing. Concurrently, epidemiological, demographic, and nutritional transitions are taking place in many countries. Current information on malnutrition and the consequences of socioeconomic disparities on global nutrition and health reveal dramatic trends. One-third of young children residing in the world's lowest-income countries suffer from growth deficits and rickets because of malnutrition. One-half of all deaths among young children are, at least in part, a consequence of malnutrition. In the developing world, 40% of women suffer from iron deficiency anaemia, a major cause of maternal mortality and low birth weight infants. Despite such worrying trends, there have been significant increases in life expectancy in almost all countries of the world. The proportion of malnourished children has generally decreased, although the actual numbers have not changed in sub-Saharan Africa and southern Asia. However, inequalities are increasing between the richest developed countries and the poorest developing countries. Social inequality is an important factor in differential mortality in both developed and developing countries. Pockets of malnutrition and a high morbidity and mortality of children are emerging in many countries, while the prevalence of obesity and non-

Table 4. Dietary energy supply (Kcal/person/day) in the world from the 1970s to the 1990s (source: FAO)

Countries

1970s

1980s

1990s

World

2430

2580

2700

Developed countries

3190

3290

3400

North America

3230

3330

3600

Europe

3240

3370

3450

Oceania

3290

3160

3330

Former USSR

3320

3370

3380

Developing countries

2120

2330

2470

Asia and the Pacific

2040

2250

2450

South America and the Caribbean

2500

2690

2690

Near East

2420

2810

2920

Least-developed countries

2030

2060

2070

communicable diseases (NCDs) is increasing. Not infrequently, it is the poor and relatively disadvantaged people who suffer both. In developed countries, the overall cardiovascular disease incidence has declined, but less so in the poorer socioeconomic classes.

Hunger and malnutrition are devastating problems afflicting poor people worldwide, in spite of increasing progress in food production and distribution during the 1980s and 1990s [22] (Fig. 2). At one end of the energy malnutrition spectrum is the problem of undernourishment and undernutrition, often described in terms of macronutrients. Low dietary energy supply, wasting, stunting, underweight, and low BMI are all used to identify the problem.

However, at the other end of the spectrum is the problem of overnourishment, leading to overweight and obesity. A high BMI is one indicator of the problem. Already a well-known phenomenon in developed countries, obesity is increasing among new urban dwellers in the developing world. Concomitantly, various weight control practices are becoming increasingly common [23]. It should be emphasised that obesity is a multifactorial, chronic disorder that warrants a continuous, complex model of intervention. Evidence linking voluntary weight loss to decreased mortality is still insufficient to recommend weight loss as a priority in the treatment of obesity. Moreover, current recommendations could be biased by social pressure [24]. The consequences of obesity, i.e. decreased productivity and increased risk of heart disease, hypertension, diabetes and certain cancers, can be as serious as those of underweight.

A diet unbalanced in macronutrients, which are the energy-providing food components, is also a cause for concern, even when total energy intake is adequate. The healthy range of macronutrient intake, expressed as a percent of total energy, can be broad: 55-75% from carbohydrates, 15-35% from fats, and 10-15% from proteins. A more modern balance of energy intake should be suggested, for example 40% from carbohydrates, 30% from proteins, and 30% from fats.

Superimposed upon the energy intake spectrum is the global problem of micronutrient malnutrition. Iron deficiency anaemia affects approximately 1.5 billion people, mostly women and children. Iodine deficiency disorders affect about 740 million people worldwide. Vitamin A deficiency-

Fig.2.Number of undernourished people in the developing world: observed and projected values (source: FAO)

induced blindness affects around 2.8 million children under 5 years of age. More than 200 million people are considered vitamin A deficient. Calcium deficiency in pregnant and lactating women can affect the development of their children, and appears as osteoporosis later in life. Severe vitamin C deficiency (scurvy) is mostly a problem in the extremely deprived, such as refugees populations. Micronutrients - minerals and vitamins - are needed for proper growth, development, and body function. Deficiencies are particularly common among women of reproductive age, children, and the immunocomprised, such as people with AIDS. Some micronutrient deficiencies affect people whose energy intake is low, but those consuming too much energy can also suffer from it.

Specific requirements have been established for most micronutrients. In most cases, deficiencies can be corrected by consuming a well-balanced diet. Variety is the key to prevention. Women are at greater risk of malnutrition and need appropriate nutritional support. They are more vulnerable than men to food unbalance because of their specific physiological requirements. Women usually have lower metabolic rates and less muscle mass than men and thus require about 25% less dietary energy per day, but they have to eat a much higher proportion of nutrient-rich foods. Women require more vitamins and minerals than men in proportion to total dietary energy intake (Table 5).

Pregnant or lactating women, need foods that are richer in energy and nutrients. During pregnancy, a woman needs an additional 300 kcal per day after the first trimester, and 500 kcal more while lactating. Compared to a non-pregnant woman, she requires almost as much protein as a man (60 g vs. 63 g per day) and more when lactating (65 g/day), up to four times more iron, 1.5 times more folate, and 20% more calcium. A lactating mother needs 40% more vitamin A and C, at least 15% more vitamin B12, and extra levels of micronutrients. Lack of access to adequate amounts and variety of food places pregnant women at greater risk of complications during pregnancy and delivery. The deaths of many infant and young children in developing countries are attributable to the poor nutritional status of their mothers.

Because they are growing rapidly, infants and young children, especially under 2 years old, need foods rich in energy and nutrients. Poor diets prevent children from achieving their full genetic potential. Severe malnutrition can cause early death, permanent disabilities, and increased susceptibility to life-threatening illnesses. A child's growth is a good indicator of his or her overall health status. Figure 3 shows the prevalence of undernutrition among young children in developing countries.

Table 5. Nutrient requirements per day for womena and men. (Data from [25])

Nutrient

Adult female

Adult male

Adult male per 1000 kcalb

Adult female per 1000 kcalc

Calcium (mg)

1000

1000

500

350

Iron (mg)d

24

11

12

4

Vitamin A (^g RE)

500

600

250

210

Vitamin C (mg)

45

45

23

16

Vitamin E (mg)

7.5

10

3.6

3.6

Niacin (mg)

14

16

7

6

Protein (g)

50

63

25

22.5

aThe needs of pregnant and lactating women are not included bBased on total dietary energy intake of 2000 kcal/day cBased on total dietary energy intake of 2800 kcal/day dBased on 12% bioavailability aThe needs of pregnant and lactating women are not included bBased on total dietary energy intake of 2000 kcal/day cBased on total dietary energy intake of 2800 kcal/day dBased on 12% bioavailability

Percent of children

Percent of children

Fig. 3. Undernutrition in children in developing countries

Fig. 3. Undernutrition in children in developing countries

Teenage mothers and their babies are particularly vulnerable to malnutrition. Girls generally grow in height and weight until the age of 18 and do not achieve peak bone mass until about 25. The diet of a chronically hungry adolescent girl cannot support adequately both her own growth and that of her foetus. Malnourished young women often give birth to underweight babies.

Your Metabolism - What You Need To Know

Your Metabolism - What You Need To Know

If you have heard about metabolism, chances are it is in relation to weight loss. Metabolism is bigger than weight loss, though, as you will learn later on. It is about a healthier, better you. If you want to fire up your metabolism and do not have any idea how to do it, you have come to the right place. If you have tried to speed up your metabolism before but do not see visible results, you have also come to the right place.

Get My Free Ebook


Post a comment