Nutritional Requirements: Types and Sources of Nutrients Sport Books Publisher

Nutrition The science of food and how the body uses it in health and disease Sport Books Publisher

Essential Nutrients Proteins Fats Carbohydrates Vitamins Minerals Water In this context, ‘essential’ refers to nutrients that the body is unable to manufacture (or not in sufficient quantities) They must be obtained from the diet Sport Books Publisher

Essential Nutrients Necessary for energy Needed for the building and maintenance of tissues Relied upon for the regulation of body functions Sport Books Publisher

Energy-Providing Nutrients Three nutrients provide the body with energy: Proteins Fats Carbohydrates Sport Books Publisher

Energy Measurements Energy is expressed in ‘kilocalories’ 1 kilocalorie = 1000 calories Kilocalorie = Calorie (note capital ‘C’) 1 kilocalorie = heat required to raise the temperature of 1kg of water 1°C An average person requires approximately 2000 kilocalories per day Sport Books Publisher

FATS ALCOHOL CARBOHYDRATES PROTEINS Calorie Densities of Various Energy Sources FATS 9 Cal/g ALCOHOL 7 Cal/g CARBOHYDRATES 4 Cal/g PROTEINS Sport Books Publisher

Proteins Found in every living cell Act as structural components for: Muscles Bones Blood Enzymes Some hormones Cell membranes Sport Books Publisher

Proteins Composed of chains of amino acids 20 commonly recognized amino acids Nine essential (can not be synthesized) amino acids Methionine Phenylalanine Threonine Tryptophan Valine Histidine Isoleucine Leucine Lysine Sport Books Publisher

Protein Individual sources of protein are ‘complete’ if they supply all nine essential amino acids Complete protein sources include animal products such as meat, cheese, fish, eggs, poultry and milk Sport Books Publisher

Protein ‘Incomplete’ protein sources include those foods that do not contain all nine essential amino acids Usually from plant sources such as grains, beans, peas, and nuts Still good sources of amino acids Foods must be combined to get all amino acids (rice and beans for example) Sport Books Publisher

Protein Protein should comprise 10-15% of total caloric intake Protein consumed in excess of needs is stored as fat Inadequate protein consumption can lead to muscle wasting Sport Books Publisher

Fats Also known as lipids Concentrated source of energy Fat serves to Provide a source of energy Insulate the body Cushion organs Aid the absorption of fat-soluble vitamins Add flavour and texture to foods Sport Books Publisher

Fats Fats in food are mostly triglycerides Include a glycerol (an alcohol) Three fatty acid molecules Sport Books Publisher

Fats Fats can be classified as Saturated Monounsaturated Polyunsaturated Based on the degree of saturation or number of double bonds that exist between carbon atoms No double bonds = saturated One double bond = monounsaturated Two or more double bonds = polyunsaturated Sport Books Publisher

Saturated Fat Monounsaturated Fat Polyunsaturated Fat Sport Books Publisher

Saturated Fats Food usually contains more than one type of fat The dominant fat determines the characteristics of the fat Saturated fats are solid at room temperature Saturated fat is found predominantly in animal products Saturated fat has also been linked to cardiovascular disease Sport Books Publisher

Unsaturated Fats Monounsaturated and polyunsaturated fats usually come from plant sources Unsaturated fat is liquid at room temperature (oil) More desirable, not linked to cardiovascular disease Unsaturated fats appear to lower blood cholesterol Also shown to reduce the risk of heart disease Sport Books Publisher

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