Last modified on 3 April 2013, at 07:53

Fundamentals of Human Nutrition/Defining Nutrition

Defining NutritionEdit

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Malnutrition is the condition that occurs when your body does not get enough nutrients. 

Causes, Incidence, and Risk Factors There are a number of causes of malnutrition. It may result from: •Inadequate or unbalanced diet

•Problems with digestion or absorption

•Certain medical conditions

Malnutrition can occur if you do not eat enough food. Starvation is a form of malnutrition.

You may develop malnutrition if you lack of a single vitamin in the diet.

In some cases, malnutrition is very mild and causes no symptoms. However, sometimes it can be so severe that the damage done to the body is permanent, even though you survive.

Malnutrition continues to be a significant problem all over the world, especially among children. Poverty, natural disasters, political problems, and war all contribute to conditions -- even epidemics -- of malnutrition and starvation, and not just in developing countries.

A study conducted by Action Against Hunger-USA (ACF-USA) among children under five in the Nuer community of Old Fangak, central Upper Nile, found that most of the malnourished children had been sick over an extended period, suffering from diarrhoea, respiratory infections and fever, or a combination of several illnesses. Disease and inadequate food intake seemed to have particularly affected children under five years old, the report stated tab. (PDF file, 669KB)

1.2.2 Macronutrient basicsEdit

As the name macro suggests carbohydrate, protein, lipids and water make up the bulk of the diet and signify the items the body requires to be consumed in large quantities. In addition the three that are typically known as macronutrients’; Carbohydrate, protein and lipids are the bodies’ main source of energy, with carbohydrate and protein providing the body with 16.8 kJ/g and lipids providing the body with 37.8 kJ/g, (Wilson, 2007) All macronutrients contain carbon, hydrogen, and oxygen the only exception is protein which also includes nitrogen.

Recommended daily intake varies depending on age and health condition, (IOM, 2005)

The body cells main source of energy, providing 35-70 of the dietary intake, which is acquired through the consumption of sugars and starches, (USDA, 2005)3, which increase the body’s blood glucose levels (Wilson, 2007). The energy supplied by carbohydrate is of particular importance to the brain the bodies’ only carbohydrate-dependent organ, USDA. (2005)2. This category also includes dietary fibre, which are either soluble or insoluble and offer several health benefits.
Carbohydrates are divided into two categories simple, which includes items made up of 1 or 2 sugars which increase the blood glucose level quickly and complex, which includes from 3 to >10 sugars and increase the bloods glucose levels more slowly . Typical sources are wheat, rice, potatoes, fruit, sugar beet and whole grains. Carbohydrates are an essential part of the diet and should not be restricted, choosing the complex variety is the healthiest option. (Harvard School of Public Health, 2013)
Carbohydrate Associated Disease
Excessive consumption of refined sugar and simple carbohydrates can contribute to obesity and the onset of type 2 diabetes, (Vorvick, 2012). Diabetes is dysfunction of the body’s ability to metabolise glucose due to insufficient levels or ineffective use of insulin, (Diabetes UK, 2013). Simple carbohydrates in food and drinks are also associated with increased risk of dental caries, (Mobley, Marshall, Milgrom, & Coldwell, 2010).

Protein should make up 10-23% of the bodies intake for energy, (USDA, 2005)1. In addition to providing energy protein also assists with the regeneration and growth of cells, acquired by the consumption of 9 essential amino acids and 11 non-essential amino acids, which are synthesised in the body, (Wilson, 2007). Typical sources of essential amino acids are meat, fish, eggs, dairy products and soya, which constitute complete proteins or combinations such as rice and lentils and peanut butter sandwiches.
Protein Malnutrition
protein-energy malnutrition (PEM) is a group of protein deficiency disorders, (Scheinfeld, 2013), including marasmus, kwashiorkor and a combination condition marasmus-kwashiorkor. marasmus is a wasting disease characterised by emancipation and is an adaptive response to starvation. Kwashiorkor in contrast is characterised by a swollen belly, but is also a wasting disease and a maladaptive response to starvation.

Lipids The lipid macronutrient group is made up of fatty acids, triglycerides, phospholipids, and sterols. Lipids should make up 20-45% of the bodies energy intake, (USDA, 2005)2. In addition to providing energy lipids also assist the body with the absorption of fat-soluble vitamins.
Fatty acids are divided into three categories saturated, which is not essential to the body and monounsaturated and polyunsaturated. There are 2 essential fatty acids that the body can’t produce linoleic acid (omega 6) and linolenic acid (omega 3). (Wilson, 2007) Excellent sources of essential fatty acids are fish and flax seed and canola oil.
Cholesterol is the most common sterol typical sources are eggs and cheese.
Lipid Associated Diseases and Malnutrition
Excessive cholesterol in the blood can lead to coronary heart disease and disease of the arteries. Of major concern is when blood levels are high in LDL cholesterol and trigylcerides, and low levels of HDL cholesterol, (Macnair, 2007).

[1]Diabetes UK. (2013). Type 2 diabetes. Retrieved from Diabetes UK:

[2]Harvard School of Public Health. (2013). Carbohydrates the bottom line. Retrieved from Harvard School of Public Health:

[3]IOM. (2005). Dietary Reference Intakes: Macronutrients. Retrieved from Institute of Medicine:

[4]Macnair, T. (2007). BBC Health. Retrieved from Cholesterol:

[5]Mobley, C., Marshall, T. A., Milgrom, P., & Coldwell, S. E. (2010). The Contribution of Dietary Factors to Dental Caries and Disparities in Caries. Retrieved from National Institute of Health:

[6]Scheinfeld, N. S. (2013). Protein-Energy Malnutrition. Retrieved from Medscape:

[7]USDA. (2005)1. Chapter 10 Protein and Amino Acids. Retrieved from Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients):

[8]USDA. (2005)2. Chapter 11 Macronutrients and Healthful Diets. Retrieved from Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients):

[9]USDA. (2005)3. Chapter 6 Dietary Carbohydrates: Sugars and Starches. Retrieved from Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients):

[10]Vorvick, L. J. (2012). Carbohydrates. Retrieved from Medline Plus:

[11]Wilson, M.-M. G. (2007, July). Overview of Nutrition. Retrieved from The Merck Manual:

1.2.3 Micronutrient basicsEdit

Micronutrients are commonly known as vitamins and minerals. They are called micronutrients because the body only requires a very small quantity of vitamins and minerals to assist the body in its normal functions. These nutrients are essential to our bodies, however our bodies are unable to produce micronutrients and they must be sourced from our diets. To gain the essential nutrients we need it is important to eat a well balanced diet that includes a range of colourful fruit and vegetables, nuts and whole grains. That way we gain such vitamins as Vitamins C to aid the immune system, Vitamin E to help fight free radical damage, or minerals such as Iron for red cell production and Calcium for strong healthy bones.

The World Health Organisation calls micronutrients "the 'magic wands' that enable the body to product enzymes, hormones and other substances essential for proper growth and development". The International Atomic Energy Agency (IAEA) have a program called 'Improving Nutrition through Nuclear Sciences', IAEA understands the essential role micronutrients play in our bodies and states "when micronutrients are not sufficient from food in the diet, significant health problems can result" and a significant amount of research has gone into understanding the physiological role and the health consequences of micronutrient deficiencies. Joint experts, the World Health Organisation and the Food and Agricultural Organisation of the United Nations conducted research in 1998 to establish clear parameters of defining micronutrients deficiencies for public health, as well as to develop preventative action and control strategies (World Health Organisation & Food and Agricultural Organisation of the United Nations, 2004).

[12] International Atomic Energy Agency. (n.d.). Micronutrient deficiency: A global challenge to health

[13] World Health Organisation. , & Food and Agricultural Organisation of the United Nations, (2004). Vitamin and mineral requirements in human nutrition. Second Edition, 1-13