Nutrition is a process by which the body uses food to sustain life , to grow , to be active , and for normal functioning of every organ and tissue . Adequate nutrition is also important for psychological well-being.

Nutrients are essential components of food. There are more than 50 essential nutrients in food. Each nutrient plays special role in the body and needs other nutrients to do its job properly . Reliance on one particular food or food group can lead to nutritional deficiencies because no one food can provide all nutrients. Eating a variety of foods is important.

Healthy eating is often mistakenly equated with dieting or low-calorie food choices. It is perfectly acceptable to enjoy modest indulgences every once in a while.

Healthy eating provides adequate energy and nutrients and is based on Canada’s Food Guide to Healthy Eating.

However, eating guidelines are just generalizations and suggested steps that you can take to ensure good health. These recommendations are for eating patterns over several days. They are not meant to apply to single meals or foods.

The best approach is to follow the 80:20 rule. This rule - which takes the socio-cultural context of food into account - states that 80% of the time you should pay attention to how you fuel your body. The other 20% of the time , have fun and throw caution to the wind. If you eat a triple hot-fudge sundae, so what. You have not ruined your good eating habits or your life. What’s important is that your food choices over the course of time represent an appropriate energy level to maintain a healthy weight. This means food that are generally low in fat and high in fibre and complex carbohydrates, including plenty of fruits , vegetables and whole grains.



Three Important Concepts.

Balance- The food guide’s recommendations are for healthy eating .They provide an eating framework; the rest is up to you.

Variety- The greater the variety within each food group , the more balanced your diet will be - and the less likely you will grow tired of any one food . Focus on eating whole foods in their natural state (I. e. fruits and vegetables ) . Whenever possible , reduce your consumption of refined or manufactured foods , such as crackers and synthetic snacks.

Moderation- Not to much , not to little. Adapt the number of servings per food group to match your activity level and watch the size of the servings . Portions in today’s super-size society are unnecessarily large.

Food’s Essential Elements.

The foods we eat provide the energy our bodies need for healthy functioning. Energy is derived from macronutrients : protein , carbohydrate and fat . Water is also essential nutrient . Vitamins and minerals are required in small quantities and are essential for many body processes , although they do not , themselves , provide energy.

Protein 1 gram of protein=4 kcal

The protein derives from the Greek word “proteins”, meaning “of prime importance”. Second to water , protein makes up the largest percentage of material in the human body- about 45%.

Proteins are found in all plant and animal cells . Proteins are made up of amino acids( commonly called “building blocks”), which linked into long chains. To visualize a molecule of protein , think of a chain-link fence and the links in the chain as the amino acids. In addition to carbon , hydrogen and oxygen atoms , amino acids contain a nitrogen ( amino) group.

Proteins are made up of 21 different amino acids. The human body is capable of producing 12 non-essential amino acids. The remaining 9 essential amino acids must be obtained from the diet.

Types of dietary proteins.

1. High-quality protein: contains all 9 essential amino acids in proper proportions . Food sources :eggs, meat, poultry, fish, milk, yogurt and cheese.

Our bodies absorb high-quality proteins more efficiently . The standard against which the value of protein is measured is the egg. The egg has arbitrarily been granted a biological value of 100% , meaning that it is the most useful and available protein.

Other foods , which have proportionately more protein, may not be as valuable as the egg because their proteins are not as complete; they lack ample amounts of one or more essential amino acids.

2. Low -quality protein: is missing one or more essential amino acids or has unbalanced amounts of amino acids. Food sources : grain products (breads, cereals, rice, pasta ), legumes ( beans, peas, lentils) and nuts and seeds.

Functions of Protein.

1. Growth and repair of body tissues- protein provides the structural matrix for many body tissues, including muscles , tendons, ligaments, skin, hair and nails. Protein is required for the growth and repair of this tissues.

2. Energy- A secondary function of protein is to provide energy when carbohydrate and fat are not available in adequate amounts. This usually occurs during “ starvation” mode, such as when a person consumes a very low-energy diet or is involved in extended physical activity like running a marathon.

Carbohydrate 1 gram of carbohydrate= 4 kcal

We eat carbohydrates to provide the body with its most efficient and accessible source of energy . Carbohydrates are an important energy source for working muscles and for the brain and nervous tissue to function properly . The 2 primary categories of carbohydrates are simple (sugars like jam, syrup, honey, fruit ) and complex ( bread, pasta, cereal, potatoes, vegetables). Our diet should consist of 55 to 65 percent carbohydrates to meet daily energy needs. The best sources are the natural sugars in vegetables , fruit, diary and rice because they also contain other essential nutrients like vitamins , minerals , and fibre.

Fat 1 gram of fat= 9 kcal

This chemical compound ,also called lipid, is a major fuel source because it is such a high concentration of calories. Fat provides essential fatty acids needed for cell membranes , production of hormones , healthy skin and the transportation of fat-soluble vitamins A , D and E. Animals products (meat, butter, diary) and plant products (oil, margarine and nuts) are common source of fat in our diet. It is recommended that we reduce the amount of saturated fat we eat. We should consume small amounts of saturated fat ( solid at room temperature) . Keeping fat intake below 30% of our total daily intake is best for health.


These are organic compounds that are necessary for good health. The body is not capable of making vitamins so they have to be supplied in the diet. Vitamins do not supply energy , but they are necessary for the metabolism of carbohydrates and fats and some interact with minerals. Vitamins are grouped into 2 categories - water soluble ( vitamin B complex and C) and fat soluble (A,D,E, and K). Water soluble vitamins are in the watery component of food and are disturbed in body fluid ( unused amounts are excreted in urine). Fat soluble vitamins are found in the fat and oily parts of food and are absorbed into fat for long term storage . The concept of vitamin supplementation has been very prevalent recently- advertisements promote wellness and decease fighting properties of supplements. They are no strong conclusions about the benefits of supplements and many believe that a balanced diet may provide all the necessary vitamins for long term health.

Minerals .

These are simple but important nutrients because they provide a variety of functions. For example , sodium and potassium assist with body fluid levels, calcium and phosphorus are essential for bone health , iron is important for haemoglobin and the transport of oxygen and iodine helps regulate metabolism . There are 20 to 30 important minerals and they are required in small amounts . Most minerals are easy accessible with a balance diet and so supplementation is rarely recommended.


This nutrient is essential for survival. About 60% of our body weight is water and it provides some very important functions. Water is used for digestion and metabolism ; it assist with chemical reactions ; it carries oxygen through blood ; it regulates body temperature ; it lubricates joints ; it removes wastes and assists with respiration . During daily life and exercise we lose body water. In order to replenish this loss of water it is recommended that we drink at least 8 to 10 glasses of water a day . Thirst is the body’s first sign of dehydration so it is not recommended to be used as a guide to water necessity. Satisfy the body’s needs by consuming regular amounts of water throughout the day.

It is important to understand fluid replacement when exercising. Try to encourage yourself to consume 1 to2 cups at least one hour before exercise (if possible consume 1 cup 20 minutes before exercise). Consume half /cup every 20 minutes during the exercise session and drink 2 cups for every pound of weight loss after exercise. Stay hydrated for good health.



1. Eat variety of foods-Follow Canada’s Food Guide and consume the recommended amounts from each food group.

2. Choose a diet low in fat and pay attention to saturated fat and cholesterol for heart health.

3. Eat plenty of vegetables, fruits and grain products.

4. Choose a diet that is reduced in simple sugars.

5. Eat a moderate amount of salt and sodium.

6 .Balance your food with physical activity.

7. Monitor caloric intake to regulate body weight to a healthy level.

8. Avoid alcoholic beverages and smoking.