Nutrition is the science behind how your body uses the components of food to grow, maintain and repair itself. Your body needs more than 50 nutrients on a daily basis in order to function properly.
The fifty nutrients belong to one of six general categories. 
*Carbohydrates
*Proteins
*Vitamins
*Fats
*Minerals
*Water
With the exception of water, the nutrients within each category all have a similar chemical make-up, but they differ in terms of how they work within the body.
Macronutrients– are the nutrients that we need in relatively large amounts everyday. The following are known as energy nutrients because they provide us with energy or calories.
Carbohydrates– are the preferred source of food energy for your body. Over 50% of your total daily caloric intake should come from carbohydrate – rich foods.
-Simple carbohydrates are also sugars and occur naturally in fruit, milk, yogurt, and fruit juices. It can also be used in less nutritious foods such as soft drinks, candy, cookies and cake.
-Complex carbohydrates come from starches found in grain products such as bread, pasta, cereal, rice and vegetables. They are made up of long chains of glucose molecules. It provides a slow, steady source of energy.
–Fibre is a type of complex carbohydrate that the body cannot digest and that is not a source of calories. It helps you stay healthy as it removes the building of blocks of cholesterol, a type of fat that increases the risk of heart disease. Furthermore, fibre can help you manage your weight. Rich source of fibre include whole grain products such as whole wheat breads/pastas, vegetables and fruit.
Protein can be found in all the cells in our bodies (muscles, tendons, ligaments, hair, skin and nails). Proteins are the building blocks of enzymes that help digest food, fight infection and build blood. They are made up of smaller sub units called amino acids.
-High quality protein sources are foods that contain all nine of these essential amino acids. Ex. Eggs, meat, fish, poultry and milk products.
-Low-quality protein sources are foods that are lacking in one or more essential amino acids. Ex. Cereal, grain products, legumes and nuts.
–Fats are a concentrated source of energy and they are especially useful during prolonged physical activity. Choosing too many higher-fat foods too often can increase a person’s risk of heart disease, diabetes, obesity or some type of cancer. Essentially, one should always try to choose higher-fat foods that also provide other nutrients such as granola bars, peanut butter, cheese and meats rather than higher-fat and less nutritious foods such as hot dogs, French fries, and potato chips.
Micronutrients are essential nutrients that are needed by our bodies only in small amounts. The following are known to help the body utilize the energy provided by carbohydrates, proteins and fats.
Vitamins are chemicals that the body needs to build and maintain its cells and to release energy from macronutrients.
Water– soluble vitamins are not stored in the bodies, so we need to eat food that contains these vitamins on a daily basis. Ex. Vitamin C.
Fat- soluble vitamins are absorbed in the small intestine and then stored in the liver. Ex. Vitamin D.
Minerals help make bones, proteins and blood.
*Calcium, obtained from dairy products, is part of the structure of bones and teeth.
*Iron is found in some meat and some dark-green vegetables which plays a role in carrying oxygen to body tissues.
*Electrolytes carry electrical charge when dissolved in the body. They are found in the fluids in your body, in the blood and in/around the cells.
The key to achieving and maintaining a healthy body weight is to balance our energy intake with our energy expenditure.
-When energy intake is equal to energy expenditure, we are in neutral energy balance.
-When we take fewer calories than we burn off, we are in negative energy balance.
-When we take in more food that we balance out with physical activity, the result is weight gain.
