1.1 nutritional requirements

NUTRITIONAL REQUIREMENTS(NR)

Introduction

• The NR of individuals vary at different stages of life and depend on a number of factors including age, sex and current health status of the individual.

• NR will also depend on:• differing physiological conditions, such as

pregnancy and breastfeeding• environmental conditions, such as temperature• varying levels of physical activity

Categories of nutrients needed by the body:

• Macronutrients - that provide the energy required for growth and replacement of cells, which are required in large amounts and include protein, carbohydrate and fat

• Micronutrients - which ensure the healthy functioning of organs and body processes. These are required in much smaller amounts and include vitamins and minerals

Malnutrition

• Can exist in two forms as outlined in Figure below; (1) Overnutrition and (2) under-nutrition.

• In Ethiopia the most common form of malnutrition is under-nutrition, which can manifest as wasting, stunting and/or deficiencies of essential vitamins and minerals (collectively referred to as micronutrients).

Types of under-nutrition

1. acute malnutrition (wasting), 2.chronic malnutrition (stunting) and 3.micronutrient deficiency.

1. Chronic malnutrition (STUNTING)

• individuals whose height is below the average expected height for their age)

• is generally a result of prolonged or repeated episodes of under-nutrition that often starts before birth.

• Stunting is strongly associated with poverty, poor health and impaired physical and mental development.

• Stunting can be reversed through ‘catch up growth’ until 2 years of age; after which it is irreversible.

2. Acute malnutrition (wasting)• A measure of thinness defined by Weight-For-Height (WFH)

or Mid Upper Arm Circumference (MUAC) measurements] • Is characterized by rapid weight loss usually due to illness

and/or reduced food intake. • Wasting can be reversed, however it is of particular

concern during emergency situations because it can quickly lead to excess morbidity and mortality.

• Acute malnutrition leads to changes in the body related to cellular composition, tissue and organ functions.

• Acute malnutrition can either present itself as severe (SAM)or moderate (MAM) and can result from type II nutrient deficiencies (see below)

3.Micronutrient deficiencies

• Individuals can have a deficiency of either Type I or type II nutrients.

Type I nutrients • Those required for adequate functioning of the

body, such as iron, vitamin A, iodine, etc. • These nutrients regulate hormonal,

immunological, biochemical and other bodily processes.

• While these deficiencies can cause major illness and increased risk of mortality, anthropometric measurements (e.g. height and weight) can be normal, although it is common for stunted or wasted individuals to also have some degree of micronutrient deficiency.

Type II nutrients

– Are the growth nutrients required to build new tissue e.g. nitrogen, essential amino-acids, potassium, magnesium, sulphur, phosphorus, zinc, sodium, etc. Deficiencies will result in the failure to grow, to repair tissue that is damaged, to replace cells that rapidly turn-over (e.g. intestine and immune cells) or to gain weight after an illness, which can lead to an increase in the risk of stunting and/or wasting.

Causes of malnutrition

• Immediate - which act on the individual• Underlying - which influence households and

communities• Basic - which act on entire societies (SEE

FIGURE BELOW)

Immediate Causes

• These include inadequate dietary intake and infection or disease.

• Malnutrition is often exacerbated by a vicious cycle between these two factors.

• Inadequate food intake can lead to a higher risk of infection or disease, and conversely disease can lead to inadequate food intake.

Underlying Causes

• The main underlying causes of malnutrition include household food insecurity,

• inadequate social and care environment,• inadequate access to health services and

environmental factors, such as poor water and sanitation facilities.

Basic Causes

• include the country’s social, economic and political situation.

• for example, the formulation and implementation of policies to address issues such as lack of capital (financial, human, physical, social, agro-ecological, technical).

WHO classification

• WHO undertook a comprehensive survey in the early 1990’s to review the existing NCHS-1977 growth standards and develop more appropriate standards for use with a wider range of children from a variety of ethnic backgrounds, in developing and developed countries.

Cont…

• The outcome of this survey was the development of new growth standards that describe how children should grow when their nutritional needs are fully met.

• These child growth standards support the notion that given the same environmental conditions, growth potential is independent of ethnic origin; therefore these standards can apply in any country.

Cont…

• The new growth standards use the same cut-off points for weight-for-height, weight-for-age, and height-for-age z-scores,

• But the cut-off points for MUAC measurement was increased from a MUAC <11cm to <11.5cm for SAM diagnosis. The MUAC cut-off for MAM diagnosis remained the same at <12.5 cm.