HNSC 1200 - Unit 1: Basics of Nutritional Sciences

Nutrition

The study of:

• the nutrients in foods

• how nutrients are used in the body; and

• the human behaviours related to food

Food

Is any substance that your body can take in and adapt to enable you to stay alive and to gain nourishment. It is a carrier of nutrients.

Diet

Is the foods and beverages that you normally consume.

Nutrients

Are the components in food that our needs for optimal functioning.

What are the six classes of nutrients? How are they divided?

There are six classes of nutrients and they can be divided into 2 groups.

A. Energy providing (meaning that the body can use the energy they contain)

1. carbohydrate

2. fat

3. protein
   

B. Other nutrients (or non-energy containing)

4. water

5. vitamins

6. minerals

Essential nutrients

Nutrients that must come from food, because the body cannot make these nutrients in sufficient quantities.

For example, the essential nutrients include the minerals, and the essential fatty acids, linoleic and linolenic acid.

Non-essential nutrients

Nutrients that the body is able to make sufficient amounts of to promote optimal health, so they do not need to rely on food intake.

Conditionally essential nutrients

Nutrients that the body can usually make enough of to meet the requirements for health. However, during specific conditions (such as increased demand due to periods of growth, illness, or injury) the body cannot make enough to meet needs, so must rely on food intake.

For example, the amino acid histadine, which is conditionally essential during periods of growth.

How is food energy measured?

Calorie

The amount of heat energy required to riase the temperature of one litre (or onr kilogram) of water by 1 Celcius.