Nutrition and Your Health Chapter 5: Lessons 1 & 2
Dec 22, 2015
What is Nutrition?
The process by which the body takes in and uses food.
Good nutrition enhances your quality of life and helps prevent diseases. Provides you with the calories and nutrients
your body needs for maximum energy and wellness.
Calories
Units of heat that measure the energy used by the body and the energy that foods supply to the body
This energy fuels everything you do, from exercising and playing sports to doing
your homework and talking with friends.
Nutrients
Substances in food that your body needs to grow, to repair itself, and to supply you with energy.
Making healthy food choices will provide your body with the nutrients it needs to help you look your best and perform your best.
Hunger vs. Appetite
Hunger is a natural physical drive that protects you from starvation.
Appetite is a desire, rather than a need, to eat.
Why Do You Eat?
Emotional needs stressed, frustrated, depressed, bored
Environmental influence family & friends cultural & ethnic background convenience & cost advertising
Carbohydrates
Starches and sugars present in foods The body’s primary energy source 60% of diet Simple vs. Complex
Simple Carbohydrates
Sugars Fructose (fruit) and lactose (milk) Sucrose (occurs naturally in many plants
and refined to make table sugar) Sugars are added to many manufactured
food products
Complex Carbohydrates
Starches Found in whole grains, seeds, nuts, legumes
(dried peas and beans) The body must break down complex
carbohydrates into simple carbohydrates before it can use them for energy
Role of Carbohydrates
Converted to glucose (sugar) Body’s main source of energy
Glucose that is not used right away is stored in the lover and muscles as a starch-like substance called glycogen.
When more energy is needed, glycogen is converted back to glucose.
Taking in more carbohydrates than your body needs (or can store as glycogen) is then stored as body fat.
Fats
Secondary energy source BUT, fats provide more than twice the
energy of carbohydrates or proteins 30% of diet Lipid – fatty substance that does not
dissolve in water Saturated vs. Unsaturated
Role of Fats
Source of energy Transport vitamins A, D, E, and K in your
blood Serve as a source of linoleic acid –
essential fatty acid that is needed for growth and healthy skin
Add flavor and texture to food Help satisfy hunger, but high in calories
Proteins
Made of long chains of substances called amino acids.
Your body can’t manufacture 9 of the 20 different amino acids The other 9 are called essential amino acids
that you must get from the foods you eat.
Complete vs. Incomplete Proteins
Complete – Contain adequate amounts of all nine
essential amino acids. Animal products (fish, meat, poultry, eggs,
milk, cheese and yogurt, soybean products) Incomplete –
Lack one or more of the essential amino acids
Beans, peas, nuts and whole grains
Role of Proteins
Body uses proteins to make enzymes (substances that control the rate of chemical reactions in your cells), hormones (regulate the activities of different cells) and antibodies (help identify and destroy disease-causing organisms).
Energy supply
Vitamins
Compounds that help regulate many vital body processes, including digestion, absorption, and metabolism of other nutrients.
Water soluble vs. Fat soluble
Water Soluble
Water-soluble vitamins dissolve in water and pass easily into the blood during digestion. The body doesn’t store these vitamins, so
you need to replenish them regularly through the foods you eat.
Figure 5.1 (pg. 119)
Fat Soluble
Absorbed, stored, and transported in fat Your body stores these vitamins in your
fatty tissue, liver and kidneys Excess build-up of these vitamins can be
toxic Figure 5.2 (pg. 120)
Minerals
Substances that the body cannot manufacture but that are needed for forming healthy bones and teeth and for regulating many vital processes. Calcium Phosphorous Magnesium Iron**
AHA Dietary Guidelines
Amount of total calories from fat: 30% Amount of saturated fat: <10% Daily cholesterol intake: <300 mg Daily sodium intake: <2400 mg
Calculations **
Carbohydrates and Proteins =
4 calories per gram Alcohol =
7 calories per gram Fat =
9 calories per gram
Saturated Fats
Solid at room temperature Animal sources High intake of saturated fats is
associated with increased risk of heart disease
Unsaturated Fats
Usually liquids (oils) at room temperature Found in vegetable sources Healthier choice! Linked to reduced risk of heart disease Monounsaturated fatty acids –
Liquid at room temp. but start to solidify when refrigerated
Polyunsaturated fatty acids – Liquid at both room temp. and refrigerated
Lipoproteins (Two Types)
Low Density (LDL) Carries cholesterol from the liver to
the tissues Deposits cholesterol on the lining of
the arteries Dietary intake affected “Bad cholesterol”
High Density (HDL) Gathers & carries excess cholesterol
back to the liver Exercise affected “Good cholesterol”
Fiber
Indigestible complex carbohydrate Found in tough, stringy parts of vegetables, fruits
and whole grains
Helps move waste through the digestive system and helps prevent intestinal problems
Reduces risk of heart disease May help reduce risk of diabetes 20-35 grams per day
Answer these questions:1. What is an empty calorie?2. How many glasses of water per day?3. What mineral is supplied by dairy products?4. What is a source of complex carbs?5. What are fat-soluble vitamins?6. What is hunger? 7. What type of fats are animals fats and tropical
oils?8. Which mineral is used to resist infection?9. What is “bad cholesterol?”10. What is the most abundant nutrient in the body?