What is Nutrition?
The science that studies food and how food nourishes our bodies and influences our health.
Nutrition is a science that studies all the interactions that occur between living organisms and food.
*Food PROVIDES nutrients/ energy.
- These are needed to keep us alive and healthy, to support growth and allow reproduction.
Why are People Interested?
- Today in our society processed foods – foods that have been specially treated or changed from
their natural state – are much more convenient with our fast placed lives.
- These changes in the Canadian food supply have made it easier to obtain a meal or snack but
they have not improved our nutritional health.
- Years ago people did not have these products and were forced to make food from fresh and
cook more often = more nutritional benefits.
Nutrition Affects All Aspects of Health
- Good nutrition enables you to do your best
- Nutrition has a role in promoting health and preventing or treating many diseases.
- Food is central to many religious and spiritual ceremonies
- Food can provide comfort and chemically effect emotional states
- Food brings people together
How important is Nutrition?
- Unhealthy nutrition patterns along with lack of physical activity increases the risk of developing
obesity and chronic diseases such as heart disease and stroke, diabetes, and types of cancer.
- What your mother ate when she was pregnant not only affects you, but might also affect the
health of your children. MAIN OBJECTIVES:
- What do we eat
> What are nutrients?
> What are calories?
- What is a nutritious diet?
- Who can you trust
What Do We Eat?
- What is food made of:
1. Animals and plants
2. What are animals and plants made of?
Food Provides Nutrients
- Essential nutrients are nutrients that must be provided in the diet bc the body either cannot
make them or cannot make them in sufficient quantities to satisfy its needs. Ex. Bodies can’t synthesize
vitamin C, but we need it. If we don’t eat it in food we will show V. C. deficiency (scurvy) if not added
back into diet can be fatal.
- Some foods have nutrients added during processing. Called fortified foods – foods to which one
or more nutrients have been added, typically to replace nutrient losses during processing ot to prevent
known inadequacies in Canadian diet. Ex. White flour, cereals, millk, orange juice, almond milk, etc.
- Natural health products are also source of nutrients in food supply. They are the middle ground
between food and drugs. They are products regulated by Health Canada that include vitamin and
mineral supplements, amino acids, fatty acids, probiotics, herbal remedies, and homeopathic and other
- Typical diet also contains substances that are not essential to body but have health promoting
> Those that come from plants: Phytochemicals ex. Broccoli has sulforaphane, reduces risk of cancer
> Those that come from animals: zoochemicals ex. Fatty acids found in fish oil, reduce risk of
Classes of Nutrients
- 6 classes of nutrients: carbohydrates, lipids, protein, water, vitamins and minerals. Can be
grouped in dif. ways
1. Energy-yielding nutrients = nutrients that can be metabolized to provide energy. Ex. Carbs,
• Energy yielding nutrients constitutes major portion of most foods and are required in lrg.
Amounts. Therefore referred to as:
2. Macronutrients – nutrients need by body in large amounts. Include water, energy yielding
nutrients. They are measured/expressed in kilograms (kg), grams (g)
• Other nutrients referred to as:
3. Micronutrients – nutrients needed by body in small amounts. Include vitamins and minerals.
Measured/expressed in milligrams (mg = 1/1000g) or micrograms (1ug = 1/1,000,000 g)
More about Macronutrients… - Carbohydrates, fat (lipids) and protein – they are energy yielding (give us energy!)
- The amount of energy they provide is measured in kilo-calories(kcal)
> Carbohydrates gives 4 kcal of energy/gram – provide readily available source of energy to body.
Include sugars in fruits, table sugar and milk (simplest form of carb). And starches such as those in
vegetables and grains (more complex carb).
> Fat gives you 9 kcal of energy/gram – concentrated source of energy in food and lightweight storage
form of energy in body. many dif. types, monounsaturated and polyunsaturated fatty acids reduce risks.
Triglycerides, saturated and cholesterol are bad.
> Protein gives you 4 kcal of energy/gram – needed for growth and maintenance of body structures and
regulation of body processes and be used to provide energy. Thousands of dif. types in body and in diet,
all made up of amino acids, dif. combinations of amino acids = dif. forms of protein.
More about Micronutrients….
- Vitamins and minerals
- Vitamins are Organic molecules – those containing carbon bonded to hydrogen - our body needs
in order to function. Many are involved in helping body use energy from carbs, protiens, lipids, others
function in processes to:
> Aid bone growth
> Blood clotting
> Oxygen transport
> Tissue growth and development
- Minerals and water are Inorganic Molecules – those containing no carbon-hydrogen bond.
- M.N. don’t provide us with energy, but we need them to function properly.
> Control nerve and muscle action
> Make and maintain tissues like bones and blood
> Needed for bone strength
> Transport oxygen
- The unit of heat that is used to express the amount of energy provided by foo