Nutrition

Health 12

Focus of Nutrition

The area of health that focuses on:– Selecting foods that contain nutrients

– Eating the number of recommended servings from the Food Guide Pyramid

– Following Dietary Guidelines

– Planning a healthful diet that reduces the risk of disease

Focus of Nutrition

– Evaluating food labels

– Developing healthful eating habits

– Protecting against food-borne illnesses

– Maintaining a desirable weight and body composition

Selecting Foods that Contain Nutrients

Nutrient – A substance in food that helps with body processes, helps with growth and repair of cells, and provides energy– There are 6 basic classes of Nutrients

Energy is measured in calories– Calorie – unit of energy produced by food and

used by the body

Classes of Nutrients

No one food contains all the nutrients needed for health

Basic classes of nutrients:– Proteins– Carbohydrates– Fats– Vitamins– Minerals– Water

Protein

Protein is a nutrient needed for:– Growth – Building, Repairing, and Maintaining body tissues– Supplying Energy

Helps the body maintain strength and resist infection

Proteins form part of every cell in the body & make-up more then 50% of total body weight

Protein (cont.)

Each gram of protein provides 4 calories of energy

Diets deficient in protein can:– Stunt a person’s growth – Impair the development of certain tissues– Impair mental development

Excess protein is burned as energy or stored as fat

Two types of proteins:– Complete Proteins– Incomplete Proteins

Complete Protein

Complete Protein is a protein that contains all of the essential amino acids

Amino Acids – the building blocks that make up proteins

– The body needs 20 amino acids to function properly (the body can produce 11 of these)

Sources:– Meat, Fish, Poultry, Milk, Yogurt, Eggs, and Soybeans

Essential Amino Acids – the 9 amino acids the body cannot produce– These must come from the foods we eat

Incomplete Protein

An incomplete protein is a protein that does not contain all of the essential amino acids

Come from plant sources:– Grains (whole Grains, pastas, and

corn)– Legumes (dried beans, peas, lentils)– Nuts and Seeds

– Combining different plant sources of incomplete proteins can provide all of the essential amino acids

Carbohydrates

Carbohydrates – main source of energy for the body Include sugars, starches, and fiber Supply 4 calories of energy per gram of food Body can only store limited amounts of

carbohydrates Excess carbohydrates converted and stored as

fat

Carbohydrates (cont.)

Sources of Carbohydrates:– Vegetables, beans, potatoes, pasta, breads, rice,

bran, popcorn, and fruit

Types of Carbohydrates: – Simple Carbohydrates– Complex Carbohydrates

Simple Carbohydrates

Simple Carbohydrates are sugars that enter the bloodstream rapidly and provide quick energy

Found naturally in fruits, honey, and milk Processed sugar (table sugar) is added to many foods

during processing (sweets, ketchup, sauces, soda)

Provide calories but few vitamins and minerals

Complex carbohydrates

Complex carbohydrates are starches and fiber Sources: grains (breads/pasta), vegetables

(potatoes/beans) Starch – food substance that is made and stored in

most plants Fiber – the part of grains and plant that cannot be

digested– Good for Digestion– Makes you feel full– Reduces cholesterol and risk of heart disease– Sources: wheat, bran, cereals, fruit, vegetables

Carbohydrates (cont.)

Carbohydrates are converted to glucose (simple sugar)

Used for energy

Excess converted to glycogen, stored in muscles (converted back to glucose when needed for energy)

Fats

A Fat is a nutrient that provides energy and helps the body store and use vitamins

1 gram of fat supplies 9 calories of energy

Store and transport fat-soluble vitamins

Fat Soluble Vitamins – vitamins that dissolve in fat and can be stored in the body

– Include Vitamins A, D, E, and K

Fats (cont.)

Fats are stored as fat tissue that surrounds and cushions internal organs

They contribute to the taste and texture of many foods

Fats are needed for:– Maintaining body heat– Store and use vitamins– Maintaining an energy reserve– Build brain cells and nerve tissues

Fats

There are two main types of fats:– Saturated Fats– Unsaturated Fats

Saturated Fats – A type of fat from dairy products, solid vegetable fat, and meat and poultry

– Usually in solid form when at room temperature– Contribute to the level of cholesterol that is in a person’s

blood Cholesterol – A fat-like substance made by the body and

found in certain foods Dietary Cholesterol – Cholesterol in food

– Found in foods of animal origins (Meats, Dairy Products) – Blood cholesterol level is combination of the dietary cholesterol

and cholesterol produced by the body

Fats (cont.)

Dietary Cholesterol:– Found in foods of animal origins (Meats, Dairy Products)– Blood cholesterol level is combination of dietary cholesterol

and cholesterol produced by the body

Prevention of high blood cholesterol levels:– Eat fewer saturated fats– Reduce the risk of heart disease and some cancers

Unsaturated Fats

Unsaturated Fat – Obtained from plant products and fish and is usually liquid at room temperature

Two types of unsaturated fats:– Polyunsaturated Fats (sunflower, corn, and

soybean oils)– Monounsaturated Fats (olive oil, canola oil)

Fats (cont.)

Visible Fat – Fat that can be seen when looking at food

Invisible Fat – Fat that cannot be seen when looking at food (ex: the eggs and shortening in a piece of cake)

Trans Fatty Acids – produced when polyunsaturated fats are hydrogenated

– Raise cholesterol and contribute to other health problems

Vitamins

Vitamin – A nutrient that helps the body use carbohydrates, proteins, and fats– Do not supply energy– Needed for a balanced diet

– Two types of Vitamins: Fat-soluble Water-soluble

Types of Vitamins

Fat-soluble vitamins – a vitamin that dissolves in fat and can be stored in the body

– There are 4 fat-soluble vitamins: A, D, E, K– Stored primarily in the liver

Water-soluble vitamins – a vitamin that dissolves in water and cannot be stored in the body

– Examples: B complex, Vitamin C

Vitamin Deficiencies

Those who do not eat a balanced diet may develop vitamin deficiencies

Vitamin C deficiency – Symptoms: Loosened teeth and gum disease

Vitamin D deficiency – Symptoms: Rickets, poor teeth, soft bones in adults

Rare in US – most common in underdeveloped countries

Foods are the best source of nutrients

Minerals

Mineral – a nutrient that regulates many chemical reactions in the body

Two types of Minerals:– Macro Minerals (calcium, sodium)

Required in amounts greater then 100mg

– Trace Minerals (iron, zinc) As important to the body as macro minerals

Minerals (cont.)

Iron – an important component of hemoglobin and functions as a carrier of oxygen in the body

Iron deficiency can lead to anemia– Condition in which the body is unable to produce sufficient

red blood cells

A person who does not get enough iron:– Susceptible to illnesses and infection– Poor appetite– Feel weak– Continually tired– Decrease in the body’s ability to transport oxygen

Minerals (cont.)

Calcium – – needed for building bones and teeth – maintains bone strength– Functions in the contraction of muscles and in

blood clotting– Sources: Milk and milk products, dark green leafy

vegetables, calcium fortified orange juice, dried beans

Sodium

Sodium – regulates and maintains the balance of fluids in the body

Source: table salt Occurs naturally in many foods and added to

many processed foods Extra salt is not needed to maintain adequate

intake

Water

Water – a nutrient that is invovled with all body processes– makes up the basic part of the blood– helps with waste removal– Regulates body temperature– Cushions the spinal cord and joints– Makes up more then 60% of body mass– Carries nutrients to all body cells and waste

products from the cells to the kidneys

Water (cont.)

Water leaves the body through perspiration and urine

People can only survive 3 days without water

Dehydration – a condition in which the water content of the body has fallen to a low level