Balanced Diet

Nutrients

• Nutrients are substances in food that serve one or more of the following purposes

– Provide a source of energy

– Provide structure

– Regulate chemical reactions in the body

Balanced diet

• To stay healthy humans need

• macronutrients (carbohydrates, proteins and fats) and

• micronutrients (mineral salts and vitamins) along with water and fibre.

Macronutrients

• Macronutrients form the major part of diet.

Carbohydrates

• Carbohydrates provide energy.

• Carbohydrates are broken down into monosaccharides and used in cellular respiration to release energy.

• Some glucose is converted to glycogen and is stored in liver, muscles and brain.

• Any excess carbohydrate is converted to fat and stored in various parts of the body.

Carbohydrates

• We get carbohydrates from:

– Bread and grains

– Rice and pasta

– Vegetables

– Fruits

Proteins

• Foods high in protein are necessary to enable us to grow and repair muscle.

• Proteins are found in:

– Meat and fish

– Beans and legumes

– Nuts and Soya products

– Dairy products and eggs

Functions of Proteins

• Form major structural material in body.

• Act as a source of energy.

• Allow internal communications system to function.

• Maintain immune system.

• Drive chemical reactions needed for life.

Lipids

• Fats are obtained from

– Plant fat- Oils (sunflower, corn, soya, etc.) and margarines

– Animal fat- Solids (butter, cheese)

Functions of Lipids

• Provide large amounts of energy.

• Compose the structure of cell membranes.

• Regulate cellular processes.

• Forms an insulating layer under the skin to keep the body warm.

Fibre

• Fibre is found in the form of plant material that we cannot absorb and is passed through the body.

• It aids in intestinal digestion, binds cholesterol and passes it out of the body along with other waste products.

• Fibre is found in:

– Vegetables and hard fruits

– Whole grains and seeds

– Brown rice

– Oats

Water

• The human body is 75% water.

• In ordinary living, we lose between 2 and 3 liters a day through our urine, sweating and exhaling.

• When exercising the body loses even more water, and is at risk of dehydration if it is not replaced.

Functions of Water

• Medium that transports nutrients, gases and waste products.

• Serves as environment where chemical reactions occur.

• Regulates body temperature.

Vitamins

• They do NOT provide structure or energy.

• Functions

– Regulate body processes.

– Promote growth & development.

– Protect body from damaging effects of toxic compounds.

– Build and maintain tissues.

– Assist in using energy from carbohydrates, protein, and lipids.

– Assist in disease prevention and treatment.

Classification of Vitamins

• Water Soluble

– Vitamin C

– B vitamins

• Fat Soluble

– Vitamins A, D, E, K

Mineral Salts

• Lack of minerals in diet can lead to a variety of serious conditions.

• Calcium is needed for the formation of your skeleton and teeth, for muscles to contract and for blood clotting to take place.

• Sodium is needed for nerves to work properly, for muscular contraction and to maintain heart beat.