Nutrients - Macronutrients

What is Food?

Food is anything that you can eat or drink to keep your body healthy. Food can perform three functions in your body - body building, repair of tissues, protection and regulation because they contain special chemical substances called nutrients. Most foods contain a variety of nutrients. Nutrients can be defined as the study of substances in food, and their relation to health.

Macronutrients

Carbohydrates

These are the compounds of carbon, hydrogen and oxygen. They include sugars, starches and fibre. The main function of sugars and starches is to supply heat and energy. Fibre acts as a regulator of bodily functions.

1.    Sugars. Most people think of sugar as the term used for brown, granulated, castor and icing sugars, but it also refers to the substance as it is found in its many natural forms in fruits and vegetables, and in prepared foods. Examples of these are mango, orange, ripe banana and paw paw; beet, carrot, sweet potato; juices and punches, cookies or sweet biscuits; preserved fruits and candies, jams, jellies, marmalade, molasses, syrup, honey and sweetened condensed milk.

2.    Starches. Starch is found in starchy root vegetables, tubers, cereals, legumes and a few fruits, e.g. cassava, yam, cush cush, dasheen, tannia; corn, wheat, rice, pigeon peas, red beans, breadfruit, and green banana.

3.    Fibre. This is the name given given to the substance that forms the framework of skins, leaves and cells of fruits and vegetables, and the outer coverings of cereals, legumes and nuts. Fibre cannot be absorbed but

a.       It serves to provide the bulk in the intestines

b.      It helps to stimulate bowel movement and prevent constipation

c.       It prevents constipation

Some good sources of dietary fibre are fruits of all types, especially those in which the skin as well as the pulp are eaten e.g. cherries, lettuce, spinach, nuts (coconut and almond), peas, beans, lentils, whole grain, cereal, corn and unpolished rice, whole wheat products.

 Fats

Fats are found in animal as well as vegetable foods. Most animal fats are solid or semi solid at room temperature, while vegetable fats are usually in liquid form and are called oils.

Vegetable fats (oils) are sometimes treated chemically to change them into solid form. Examples of these are shortening and margarine.

Fats are composed of the same chemical elements as carbohydrates – carbon, hydrogen and oxygen – and are therefore a source of heat and energy. Apart from this function, fats are also important a source of heat and energy. Apart from this function, fats are also important because they provide fatty acids, which are needed by body cells. They also act as carriers of the fat-soluble vitamins.

Sources of fat in the diet are: milk, cheese, eggs, fatty meats, oily fish, butter, margarine, shortening, ghee, lard, coconut, peanuts, avocado pear, ackee, cooking oils.

 

Proteins

These are composed of the same chemicals as carbohydrates and fats, but they also contain nitrogen. It is the presence of this element that enables proteins to do their main work, which is body building. They are also a source of energy. Proteins are found in both animal and vegetable foods. Animal sources are: meat, fish, milk, cheese, eggs. Vegetable sources are cereals and cereal products, legumes and nuts.