108. CCA Study Notes: Basic Nutrition and Essential Nutrients

The Big Picture

Your body takes in food and fluids, breaks them down, absorbs what it needs, and uses those substances to support normal body functions. This whole process is called nutrition.

Good nutrition supports growth, healing, and the maintenance of body functions. Food and fluids provide six main groups of nutrients: proteins, carbohydrates, fats, vitamins, minerals, and water.

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Course Notes: Key Ideas You Need to Know

Understanding Nutrition

Nutrition means the processes involved when the body takes in, breaks down, absorbs, and uses food and fluids.

Several processes make up nutrition:

• Ingestion means taking food and fluids into the body.
• Digestion means physically and chemically breaking down nutrients so the cells can use them.
• Absorption means substances pass through the intestinal wall and enter the blood.
• The body then uses the absorbed nutrients.

Nutrients are substances in food and fluids that the body ingests, digests, absorbs, and uses.

Why Good Nutrition Matters

Good nutrition supports:

• growth
• healing
• maintenance of body functions

A well-balanced diet needs suitable foods and the correct number of calories to maintain a healthy weight range.

A diet high in fat and empty calories, which provide calories but lack nutrients, can lead to unwanted health problems.

People who follow Canada’s Food Guide (2019) will obtain the nutrients they need for a balanced diet. Canada’s Dietary Guidelines explains how health care workers and policymakers can promote healthy eating and nutritional well-being.

The Six Groups of Nutrients

Nutrients fall into six main groups:

1. proteins
2. carbohydrates
3. fats
4. vitamins
5. minerals
6. water

Each group has different functions in the body.

Energy and Calories

Proteins, carbohydrates, and fats provide fuel for energy.

A calorie measures the energy produced when the body burns food.

Nutrient	Calories per gram
Carbohydrate	4 calories
Protein	4 calories
Fat	9 calories

Fat provides more than twice as many calories per gram as carbohydrate or protein.

Protein

Protein supports tissue growth and repair.

Sources of protein include:

• meat
• fish
• poultry
• eggs
• milk and milk products
• cereals
• beans
• peas
• nuts

Animal products are the best sources of protein. People who do not eat animal products must get enough protein from plant sources. Plant proteins are best eaten in combinations, such as beans and rice.

Protein deficiency can result in severe malnutrition. Children and older people who do not eat properly have the greatest risk.

Carbohydrates

Carbohydrates provide energy. They also provide fibre, which supports bowel elimination and regularity.

Most carbohydrates come from plants.

There are three main kinds of carbohydrates:

Simple Sugars

Simple sugars occur in:

• table sugar
• fruits
• fruit juices

Starches

Starches occur in:

• bread
• pasta
• rice
• potatoes

Fibre

Fibre occurs in foods such as:

• bran
• nuts
• seeds
• raw fruits with skins

Fibre cannot be digested. It passes through the intestines undigested.

During digestion, most carbohydrates are broken down into sugars and absorbed into the bloodstream. Fibre is the exception because it is not digested.

Fats

Fats have several functions. They:

• provide energy
• help the body use certain vitamins
• add flavour to food

Some fat is necessary in the diet.

Dietary fat that the body does not need is stored as body fat. Excess calories from other sources can also be stored as body fat.

There are three main types of dietary fat.

Saturated Fat

Saturated fat occurs in animal and dairy products such as:

• meat
• butter
• milk
• cheese

Trans Fat

Trans fat occurs in foods such as:

• margarine
• shortening
• store-bought cookies
• cakes
• pies
• doughnuts
• fried foods

Trans fat is the least healthy type of fat.

It forms when liquid oil is chemically changed into a more solid substance. It is used to increase the flavour and shelf life of foods.

Unsaturated Fat

Unsaturated fat occurs in:

• fish
• many vegetable oils
• canola oil
• olive oil

Unsaturated fat is healthier than saturated fat and trans fat.

Vitamins

Vitamins are needed every day for normal growth and body function. They do not provide calories.

Each vitamin has specific functions. A lack of a particular vitamin can lead to illness.

Fat-Soluble Vitamins

Vitamins A, D, E, and K are fat-soluble vitamins.

The body stores excess amounts of these vitamins. Excess doses can cause complications.

Water-Soluble Vitamins

Vitamin C and the B-complex vitamins are water-soluble vitamins.

The body gets rid of excess amounts of these vitamins through urine.

Older people are at risk for vitamin deficiencies because aging affects the body’s ability to absorb certain vitamins.

Major Vitamins, Functions, and Sources

Vitamin A

Functions:

• growth
• vision
• healthy hair
• healthy skin
• healthy mucous membranes
• resistance to infection

Sources: Liver, spinach, leafy green and yellow vegetables, yellow fruits, fish liver oils, egg yolk, butter, cream, and whole milk.

Vitamin B1, Thiamine

Functions:

• muscle tone
• nerve function
• digestion
• appetite
• normal elimination
• carbohydrate metabolism

Sources: Meat or fish, eggs, breads, pastas, cereals, oatmeal, potatoes, peas, beans, soybeans, and peanuts.

Vitamin B2, Riboflavin

Functions:

• growth
• vision
• protein metabolism
• carbohydrate metabolism
• healthy skin
• healthy mucous membranes

Sources: Milk and milk products, liver, leafy green vegetables, eggs, breads, and cereals.

Vitamin B3, Niacin

Functions:

• protein metabolism
• fat metabolism
• carbohydrate metabolism
• nervous system function
• appetite
• digestive system function

Sources: Meat, pork, liver, fish, peanuts, breads and cereals, green vegetables, and dairy products.

Vitamin B12

Functions:

• formation of red blood cells
• protein metabolism
• nervous system function

Sources: Liver, meats, poultry, fish, eggs, milk, and cheese.

Folic Acid

Functions:

• formation of red blood cells
• intestinal function
• protein metabolism

Sources: Liver, meats, fish, poultry, leafy green vegetables, and whole grains.

Vitamin C, Ascorbic Acid

Functions:

• formation of substances that hold tissues together
• healthy blood vessels
• healthy skin and gums
• healthy bones and teeth
• wound healing
• prevention of bleeding
• resistance to infection

Sources: Citrus fruits, tomatoes, potatoes, cabbage, strawberries, green vegetables, and melons.

Vitamin D

Functions:

• absorption and metabolism of calcium and phosphorus
• healthy bones

Sources: Fish liver oils, milk, butter, liver, and exposure to sunlight.

Vitamin E

Functions:

• normal reproduction
• formation of red blood cells
• muscle function

Sources: Vegetable oils, milk, eggs, meats, cereals, and leafy green vegetables.

Vitamin K

Function: Blood clotting.

Sources: Liver, leafy green vegetables, egg yolk, and cheese.

Minerals

Minerals are chemical substances found in plant and animal foods.

Each mineral has specific functions in the body. For example, calcium and phosphorus help form strong bones and teeth.

Major Minerals, Functions, and Sources

Calcium

Functions:

• formation of teeth and bones
• blood clotting
• muscle contraction
• heart function
• nerve function

Sources: Milk and milk products, leafy green vegetables, whole grains, egg yolk, dried peas and beans, and nuts.

Phosphorus

Functions:

• formation of bones and teeth
• use of proteins, fats, and carbohydrates
• nerve function
• muscle function

Sources: Meat, fish, poultry, milk and milk products, nuts, egg yolk, and dried peas and beans.

Iron

Function: Helps red blood cells carry oxygen.

Sources: Liver, meat, eggs, leafy green vegetables, breads and cereals, dried peas and beans, and nuts.

Iodine

Functions:

• thyroid gland function
• growth
• metabolism

Sources: Iodized salt, seafood, and shellfish.

Sodium

Functions:

• fluid balance
• nerve function
• muscle function

Sources: Almost all foods.

Potassium

Functions:

• nerve function
• muscle contraction
• heart function

Sources: Fruits, vegetables, cereals, meats, and dried peas and beans.

Zinc

Functions:

• growth
• healing
• immune system function

Sources: Meat, poultry, whole grains, dried peas and beans, and eggs.

Water

Water is the most important nutrient necessary for life.

The body needs water for:

• maintaining cell function
• regulating body temperature
• delivering nutrients
• removing waste
• carrying out other body processes

Water enters the body through foods and fluids.

The body loses water through:

• urine
• feces
• perspiration through the skin
• expiration through the lungs

Fluid Intake and Output

Intake is the amount of fluid taken into the body.

Output is the amount of fluid lost from the body.

The amount of fluid taken in and the amount lost must remain balanced. Inadequate water intake or excessive fluid loss can result in death.