Nutritional Status and Food Security. Learner Notes

Transcription

1 Nutritional Status and Food Security Learner Notes This course is funded by the European Union and implemented by the Food and Agriculture Organization. FAO, 2007

2 Table of contents Learning objectives... 2 Introduction... 2 What is malnutrition?... 3 Causes of malnutrition... 4 Conceptual frameworks... 6 Nutritional status, health, mortality and low birth weight... 7 Summary If you want to know more Learner Notes 1

3 Learning objectives At the end of this lesson you will be able to: define the concept of malnutrition; identify the factors influencing nutritional status; and be aware of the relationships between nutrition, food security, health and mortality. Introduction The factors affecting an individual s nutritional status are many and diverse. Understanding these factors is essential in order to assess malnutrition, to design programmes which tackle nutrition problems, and to correctly inform programme management and evaluation. Understanding malnutrition is also important as it carries heavy costs on individuals and households, communities and nations. In fact, due to malnutrition, millions of lives are destroyed by death and disability, both mental and physical. Besides being morally unacceptable, this implies economic costs, in terms of lost productivity and income caused by premature death, lower physical capacity, absenteeism and lower educational and occupational opportunities. Learner Notes 2

4 What is malnutrition? Nutritional status is the physiological state of an individual, which results from the relationship between nutrient intake and requirements and from the body s ability to digest, absorb and use these nutrients. The term malnutrition indicates a bad nutritional status. Malnutrition refers to all deviations from adequate nutrition, including undernutrition, overnutrition and specific deficiencies (or excesses) of essential nutrients such as vitamins and minerals. The terms malnutrition and undernutrition are often used loosely and interchangeably, although a distinction needs to be made at all times. Malnutrition arises either from deficiencies or excesses of specific nutrients, or from undiversified diets (wrong kinds or proportions of foods). Malnutrition may arise from imbalance, excesses or deficiency of specific nutrients, for example, iodine, vitamin C, iron and vitamin A. Undernutrition is the outcome of insufficient food caused primarily by an inadequate intake of dietary or food energy. It is defined as a dietary energy intake below the minimum requirement level to maintain the balance between actual energy intake and acceptable levels of energy expenditure. Malnutrition" and "undernutrition" often both refer to nutritional situations that are typical in populations belonging to the low-income and poor socio-economic groups of developing countries. However, in many developing countries, under- and overnutrition are occurring simultaneously among different population groups. This phenomenon is referred to as the double burden of malnutrition. Learner Notes 3

5 Background information The double burden of malnutrition refers to the co-existence of undernutrition, micronutrient deficiencies, overweight/obesity and other nutrition-related chronic diseases in the same countries, in the same communities and even in the same households. This phenomenon is not limited to upper-income developing countries, but is occurring across the globe in countries with very different cultures and dietary customs. When poor economic conditions improve, amounts and variety of food consumed tends to rise and mortality rates of infant and young children tend to fall as communicable diseases are more successfully put under control. This may be accompanied by rises in obesity and diet related non-communicable diseases which may co-exist with high levels of child undernutrition. Causes of malnutrition Poverty is the root cause of malnutrition. Food security, health and care are the underlying causes as we will consider later. Most micronutrient deficiencies primarily affect poor and disadvantaged households whose members cannot produce or procure adequate food, who live in marginal or unsanitary environments without access to clean water and basic services, who lack access to appropriate education and information, or are otherwise socially disadvantaged. However, overnutrition and dietary imbalances, which may lead to chronic diseases, cut across many socio-economic boundaries. Nutritional status is influenced by multiple and interrelated factors. The most important factors can be grouped under the broad categories of food, health and care. FOOD: The availability of, access to and consumption of adequate quantities of safe good quality nutritious food is an important factor influencing nutritional status. Nutritional well-being is influenced by the nutrient content of food consumed and its absorption by the body, in relation to other requirements determined by age, sex, level of physical activity and health status, as well as the efficiency of nutrient utilization by the body. Learner Notes 4

6 HEALTH: Health and sanitation are essential for nutrition, yet they are beyond the reach of the majority of the world's population. Infectious disease and inadequate diet act together, each aggravating the effects of the other to produce what is referred to as the "malnutrition and infection cycle". Nutritional requirements are higher during and following episodes of infection. Chronic or frequent acute infections make it almost impossible to maintain adequate nutritional status. CARE: Care and feeding practices require time, attention and support and are essential to meet the physical, mental and social needs of individuals. The knowledge, attitudes and practices of household members largely determine the nutritional status of the household. An incomplete understanding of the body's nutritional needs and lack of knowledge of how to meet these needs with available foods can lead to malnutrition. Food, health and care are interrelated, and actions affecting one area may have significant consequences on another. For example, adoption of sustainable and labour-saving agricultural technologies may influence nutrition not only through improved food supplies and income, but also through their beneficial impact on sanitation and health and on the time available for providing care to household members. Development policies, which affect the economy and the society as a whole, usually are not included in the domain of nutrition as such. However, they impact considerably on the nutritional well-being of the population, and their effects may be monitored on food, health and care. Learner Notes 5

7 Conceptual frameworks The most commonly used framework for understanding the causes of malnutrition is adapted from the UNICEF conceptual framework. This framework sets out causes that operate at three levels: immediate, underlying and basic, whereby factors at one level influence other levels. There are other conceptual frameworks for malnutrition, such as the Food Insecurity and Vulnerability Mapping System (FIVIMS) framework for food security, livelihoods and nutrition. Learner Notes 6

8 The key difference between the UNICEF and FIVIMS framework is that the latter gives a greater centrality to food availability, access, consumption and utilization and their determinants. However, health and sanitation and care practices still occupy an important place within the framework. Nutritional status, health, mortality and low birth weight To better understand the concept of malnutrition and its implications, let s consider the relationships between nutritional status and health status, mortality and low birth weight. Nutritional status and Health status. Nutrition and health are closely linked, as disease contributes to malnutrition, while malnutrition makes an individual more susceptible to disease. There is a vicious cycle in which malnutrition and diseases influence each other. This vicious cycle in which one exacerbates the other is known as the malnutritioninfection cycle and can eventually lead to severe malnutrition and death. Malnutrition-infection cycle A. Inadequate dietary intake leads to weight loss, growth faltering and reduced immunity, which lower the body s ability to resist infection. B. This causes longer, more severe and more frequent disease episodes. C. This leads to loss of appetite, malabsorption of nutrients, altered metabolism and increased nutrient needs. D. This results in inadequate dietary intake. Certain diseases are particularly frequent causes of poor growth. Among these are diarrhoea, respiratory infections, HIV/AIDS and malaria. Moreover, certain diseases may predispose a person to certain types of malnutrition; vice versa, certain types of malnutrition may predispose a person to certain types of infection. For example, lack of vitamin A can predispose a person to measles. The relationship between nutrition and infection is also affected by the type of caring that takes place for sick individuals. Learner Notes 7

9 The relationship between nutrition and disease can be observed in the seasonal changes in nutritional status. Seasonal changes in nutritional status 1 are more evident in rural populations, especially when they depend on a single harvest. However, the seasonal peaks of malnutrition coincide not just with the hungry season, when food may be in most scarce supply, but also when the frequency of certain diseases is highest, particularly diarrhoea and malaria. Nutritional status and mortality. It is often assumed that as malnutrition increases so does mortality, but the reality is more complex. In fact, the relationship between malnutrition and mortality is not linear but increases exponentially. In other words, mortality increases exponentially with declining nutritional status. Many factors impact mortality, especially the health environment and caring capacity, which are often compromised in situations of conflict and displacement. In emergencies, where exposure to disease varies, there may therefore be varying levels of mortality associated with the same level of malnutrition. Consequently, mortality rates cannot be predicted from prevailing rates of malnutrition. Example: Northern Iraq refugees In 1991 during the northern Iraq refugee crisis, a survey of Kurdish refugees found a prevalence of acute malnutrition among under-fives of only 4.3% (which is low) but a crude mortality rate (CMR) of 3/10,000/day, which is very high. Most deaths were due to diarrhoea and dehydration. 1 Many communities, especially in the rural areas, experience periods in the year when malnutrition levels are higher. Changes in the levels of malnutrition are influenced by seasonal patterns such as: cropping patterns, food availability, disease, child care, income sources, price of foods, labour demand. These expected changes in malnutrition need to be taken into account when interpreting changes in observed rates of malnutrition. Learner Notes 8

10 Nutritional status and low birth weight. It is estimated that each year 24 million babies are born with low birth weight (LBW), which means less than 2.5 kg. Ninety five percent of these events occur in developing countries. LBW puts infants at greater risk of neonatal death and is a major cause of poor growth and development in later childhood. Undernutrition in utero is also associated with certain chronic diseases in adult life. Although LBW can be due to a number of factors, such as a woman s small size, uterine infections, smoking and malarial infection, the most significant cause is poor maternal nutrition. The cycle of poor nutrition perpetuates itself across generations. The following diagram by the Standing Committee on Nutrition shows the intergenerational cycle of growth failure: Young girls who grow poorly become stunted women and are more likely to give birth to LBW infants. If those infants are girls, they are likely to continue the cycle by being stunted in adulthood, if something is not done to break the cycle. Adolescent pregnancy heightens the risk of LBW and the difficulty of breaking the cycle. Learner Notes 9

11 Summary Malnutrition refers to all deviations from adequate nutrition, including undernutrition (and overnutrition) resulting from inadequacy (or excess) of food. Malnutrition carries heavy human and economic costs on individuals and households, communities and nations. Malnutrition and undernutrition are often used as synonyms. However, a clear distinction needs to be made at all times. The co-existence of undernutrition, micronutrient deficiencies, overweight/obesity and other nutrition-related chronic diseases occurs in the same countries, in the same communities and even in the same households throughout the world today, posing one of the greatest challenges to national policy makers. This phenomenon is referred to as the double burden of malnutrition. Even if poverty is the root cause of undernutrition, malnutrition has multiple and interrelated causes. The direct causes of malnutrition can be grouped under the broad categories of: food, health and care. If you want to know more The double burden of malnutrition Case studies from six developing countries. FAO Food and Nutrition Paper 84, Rome Measurement and Assessment of Food Deprivation and Undernutrition - FIVIMS Proceedings, International Scientific Symposium held in FAO, Rome June FAO Conducting small-scale nutrition surveys: A field manual. FAO, 1990, 186p, English, Spanish, French ISBN Body mass index - A measure of chronic energy deficiency in adults. FAO Food and Nutrition Paper 56, United Nations Standing Committee on Nutrition Issue No. 33 Diet-related Chronic Diseases and the Double Burden of Malnutrition in West Africa, 2006, pages Learner Notes 10

12 Incorporating Nutrition Considerations into Development Policies and Programmes: Brief for Policy-Makers and Programme Planners in Developing Countries, FAO The State of Food Insecurity in the World (SOFI): monitoring progress towards the World Food Summit and Millennium Development Goals (FAO-SOFI, 2004) Additional Reading: Nutrition and development: a global challenge - adapted from Nutrition and development - a global assessment, written by FAO and WHO for the International Conference on Nutrition, United Nations Standing Committee on Nutrition/Administrative Committee on Coordination (ACC/SCN) Second report on the World Nutrition Situation: Vol.1: Global and Regional Results, ACC/SCN Geneva, Conducting small-scale nutrition surveys: A field manual. FAO, 1990, 186p, English, Spanish, French ISBN Learner Notes 11