What is Nutrition?

Nutrition is the science of food; nutrients and the substances therein; their action, interaction and balance in relation to health and disease and how it is processed in the body that is ingestion, digestion, absorption, transportation, utilisation and excretion.

What are Nutrients: These are substances that are essential for health that the body cannot make on it’s own or makes in amounts too little to support health hence these are to be gotten from the diet.

Nutrients are classified into Macro-nutrients and Micro-nutrients. Macro and Micro in the sense that others are needed in large quantities as compared to others and not that (micro-nutrients) they are less important or needed. Macro-nutrients include Carbohydrates, Proteins and Fats while micro-nurients include vitamins and minerals.

MACRONUTRIENTS

Carbohydrates

These are the primary source of energy and are broken down into glucose used as fuel for cells. They provide 4kcal per gram and should make up 50% of your daily calories. Foods sources of carbohydrates include cereals, roots and tubers, starchy vegetables and, sweet fruits, pastries etc.

Carbohydrates can either be simple or complex. Simple carbohydrates are those that are easily broken down in the body and cause a rapid increase in blood sugar levels when eaten they include natural sugars found in whole foods as well as processed and added sugars. Complex carbohydrates are those that are not easily broken down and provide a slow and steady increase in blood sugar levels this is because they contain Fibre.

FIBRE

This is a type of plant-based carbohydrate that the body cannot digest, it consists of soluble and insoluble fibres.

Importance of Fibre

1. Soluble fibres dissolves in water, helping them to soak up water thus retaining water to soften waste and forming a gel like mix to facilitate smooth transit of waste.
2. Insoluble fibre doesn’t dissolve in water but adds bulk to waste this bulkier stool stretches the walls of the intestine allowing for nerve stimulation responsible for muscle squeezing enabling waste movement.
3. Fibre serves as a prebiotic for colonic bacterial fermentation that support your gut lining and overall health.

Proteins

These are used as body builders and repairers. Proteins should make up 15% of the daily calories and these provide the body with 4kcals per gram. Protein sources include fish, meat, eggs and legumes. The Recommended Daily Allowance of proteins ranges from 0.8 to 2.0 grams per kilogram of your body weight depending the lifestyle and physiological needs of the body. Proteins are made of amino acids, there are twenty (20) standard amino acids. Of the twenty, nine (9) are essential amino acids and eleven (11) are non essential. Essential means those proteins that cannot be synthesised by the body hence relying on external sources only i.e diet.

Proteins can be said to be either complete or incomplete depending on whether those sources contain all the essential amino acids. Proteins considered to be essential are mainly from animal sources with some few exceptions with plant sources which include soy beans, quinoa, Chia seeds. In order to achieve complete protein diet in plants you need to take complementary proteins for example eating beans or lentils with rice or other grains since beans is deficient in methionine an essential amino acid found in grains.

Fats

These are the main source of stored energy . Lipids help to regulate temperature and provide protection to delicate organs of the body. Fats provide 9kcal per gram and should contribute 35% of daily calories to your diet. Sources of fat include diary products and nuts, seeds and plant oils. Fats can be saturated, unsaturated or could have trans fats.

# Saturated fats are gotten from animal sources with an exception of tropical oils such as coconuts.

# The unsaturated are from plants including fish sources, these could be either Monounsaturated (MUFAs) and Polyunsaturated fatty acids (PUFAs).

#Transfats: these come from two main sources including artifical industrial fats (from partially hydrogenated oils) and natural animal fats . The primary sources include highly processed foods like fast foods.

MICRONUTRIENTS

Vitamins and Minerals

These are nutrients needed in smaller amounts but these support normal metabolism and tissue function. They are found in diverse foods but mostly in fruits and vegetables. their Recommended Daily Allowances depend on the specific mineral or vitamin

Vitamins

These are divided into fat soluble and water soluble vitamins. Fat soluble vitamins include vitamins A, D, E and K. The water soluble vitamins include the B complex vitamins that is B1, B2, B3, B6, B9 & B12 and vitamin C.

Minerals

Minerals can be classified as Major and Minor. Major ones include Calcium, Magnesium, Potassium, Sulfur, Chloride, Sodium and Phosphorous while Minor ones include Copper, Zinc, Iron, Iodine, Selenium and Fluoride, Manganese, Molybdenum, Chromium

Balancing nutrients

Recall our definition of nutrition with reference to a particular phrase “balance in relation to health and disease”. Proper nutrition entails adequate consumption of nutrients while at the same time guarding against too much. Therefore some examples of health consequences of overnutrition and undernutrition are provided below.

Carbohydrates

# Undernutrition of carbohydrates will result in Kwashiorkor, Marasmus, Ketoacidosis

# Overnutrition of Carbs will result in Obesity, Diabetes type 2, Cardiovascular diseases, Dental caries

Proteins

# Undernutrition of proteins will cause Protein Energy Malnutrition (PEM), Anemia, Immune system failure, Muscle wasting, Fatty liver etc

# Overnutrition will cause Kidney stones, Cancer risk, Bone Mineral density reduction, Coronary Heart Diseases (CHD)

Fats

# Undernutrition will bring about Fat soluble vitamins deficiency, increased susceptibility to infection

# Overnutrition will result into Diabetes type 2, Obesity, Cancers, Cardiovascular diseases

Undernutrition of Vitamins and Minerals

Micronutrients deficiency will result into what is called ‘Hidden Hunger’ because early health damage may happen inside the body without clear warning signs until severe illness occur. Lack of one micronutrients typically is associated with deficiency of other micronutrients.

Overnutrition of micronutrients leads to toxicity since these are needed in smaller amounts . Usually results in disturbed cell function or tissue function and is largely associated with people who take supplements as compared to those who obtain nutrients from natural sources.

References

1. Latham, M.C. 1997. Human Nutrition in the developing World. Food and nutrition series no.29, FAO, Rome. ISSN 1014-3181
2. Geissler, C; Powers, H. 2005. Human Nutrition. Eleventh edition, Elsevier Limited. ISBN 98 0443 0356 4
3. Thomas, B. and Bishop, J. 200. An Essential Tool for Nutrition and Dietetic Professional. Oxford University Press. ISBN- 1O: 140 135255; ISBN- 13: 978- 1405 135252.