1. Nutrition
Chapter 8

2. Lecture Objectives
List the six essential nutrients and describe their functions in the body.
List the acceptable macronutrient distribution ranges.
Explain the difference between the following:
Complete and incomplete proteins
Saturated, unsaturated, and trans fat
Simple and complex carbohydrates
Soluble and insoluble fiber
Explain the role of fiber and antioxidants in the body.

3. Nutritional Requirements: Components of a Healthy Diet
Essential nutrients
Proteins
Fats
Carbohydrates
Vitamins
Minerals
Water
Essential nutrients = substances the body must get from food because it cannot manufacture them at all or fast enough to meet its needs

4. Acceptable Macronutrient Distribution Ranges
CHO
CHO (45-65%)
FAT
FAT (20-35%) - 10% saturated
PRO
PRO (10-35% or less)
Three classes of essential nutrients supply energy
Kilocalorie = a measure of energy content in food; the amount of heat it takes to raise the temperature of 1 liter of water 1°C; commonly referred to as “calorie”

5. Proteins: The Basis of Body Structure
Protein is a compound
9 / 20 common amino acids in foods are essential
Protein = a compound made of amino acids that contains carbon, hydrogen, oxygen, and nitrogen
Proteins form key parts of the body’s main structural components—muscles and bones—and of blood, enzymes, cell membranes, and some hormones

6. Complete and Incomplete Proteins
Complete protein sources
Meat, fish, poultry, eggs, milk, cheese, and soy
Incomplete protein source
Plants, including legumes, grains, and nuts
Complete protein sources = foods that supply all the essential amino acids in adequate amounts
Incomplete protein sources = foods that supply most but not all essential amino acids

7. Recommended Protein Intake
0.8 gram per kilogram (0.36 gram per pound) of body weight daily
Acceptable Macronutrient Distribution Range =
10–35% of total daily calories as protein

8. Protein Sources 3 ounces lean meat, poultry, or fish 1/2 cup tofu
20–25 grams of protein
1 cup legumes
15–20 grams of protein
1 cup milk or yogurt or 1-1/2 ounces cheese
8–12 grams of protein
Cereals, grains, nuts, vegetables
2–4 grams of protein per serving

9. Fats: Essential in Small Amounts
What role do fats play in my diet?
Essential fats are key regulators
Fats supply energy, insulate the body, support and cushion organs, absorb fat-soluble vitamins, add flavor and texture to foods
Essential fats (linoleic acid and alpha-linolenic acid) are key regulators of body process such as the maintenance of blood pressure and the progress of a healthy pregnancy

10. Types and Sources of Fats
Saturated fat
Monounsaturated fat
Polyunsaturated fat
Trans Fat
Saturated fat = a fat with no carbon-carbon double bonds; usually solid at room temperature
Monounsaturated fat = a fat with one carbon-carbon double bond; usually liquid at room temperature
Polyunsaturated fat = a fat with two or more carbon-carbon double bonds; usually liquid at room temperature
Two key forms of polyunsaturated fats:
Omega-3 fatty acids are produced when the endmost double bond of a polyunsaturated fat occurs three carbons from the end of the fatty acid chain
Found primarily in fish
Omega-6 fatty acids are produced when the endmost double bond of a polyunsaturated fat occurs six carbons from the end of the fatty acid chain
Found primarily in certain vegetable oils, especially corn, soybean, and cottonseed oil
Trans Fatty Acids: The process of hydrogenation, in which hydrogens are added to unsaturated fats, produces a mixture of saturated fatty acids and standard and trans forms of unsaturated fatty acids
Trans fatty acids have an atypical shape that affects their chemical activity
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Fats affect blood cholesterol levels
Low-density lipoprotein (LDL) = “bad” cholesterol
High-density lipoprotein (HDL) = “good” cholesterol
Saturated and trans fats raise levels of LDL; trans fats also lower levels of HDL
Unsaturated fats lower levels of LDL
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Fats also affect triglyceride levels, inflammation, heart rhythm, blood pressure, and cancer risk
Best choices = monounsaturated fats and polyunsaturated omega-3 fats
Limit intake of saturated and trans fats

11. Fats and Health Fats affect blood cholesterol levels
“Bad” cholesterol vs. “good” cholesterol
Saturated and trans fats vs. unsaturated fats
Fats also affect triglyceride levels, inflammation, heart rhythm, blood pressure, and cancer risk
Best choices = monounsaturated fats and polyunsaturated omega-3 fats
Limit intake of saturated and trans fats
Low-density lipoprotein (LDL) = “bad” cholesterol
High-density lipoprotein (HDL) = “good” cholesterol
Saturated and trans fats raise levels of LDL; trans fats also lower levels of HDL
Unsaturated fats lower levels of LDL

12. Total Fat Content of Foods
Talk about importance of food choices. Some are everyday foods, some are sometimes foods. There is no “bad” food, all foods in moderation is key.

13. Recommended Fat Intake
Adequate daily intake of fat:
Women = 13 grams
Men = 18 grams
Acceptable Macronutrient Distribution Range =
20–35% of total daily calories as fat

14. Carbohydrates: An Ideal Source of Energy
Primary Function
Some cells use only carbohydrates for fuel
Body’s preferred fuel source
Broken down and stored during digestion
The primary function of dietary carbohydrate is to supply energy to body cells.
Some cells, such as those in the brain, nervous system, and blood, use only carbohydrates for fuel
During high-intensity exercise, muscles get most of their energy from carbohydrates
During digestion, carbohydrates are broken into single sugar molecules such as glucose for absorption; the liver and muscles take up glucose and store it in the form of glycogen

15. Simple and Complex Carbohydrates
Simple carbohydrates contain one or two sugar units in each molecule
Complex carbohydrates consist of chains of many sugar molecules
Simple carbohydrates contain one or two sugar units in each molecule
Found naturally in fruits and milk and added to many other foods
Include sucrose, fructose, maltose, and lactose
Complex carbohydrates consist of chains of many sugar molecules
Found in plants, especially grains, legumes, and tubers
Include starches and most types of dietary fiber

16. Whole Grains
Refined carbohydrates usually retain all the calories of a whole grain but lose many of the nutrients
Before they are processed, all grains are whole grains consisting of an inner layer of germ, a middle layer called the endosperm, and an outer layer of bran
During processing, the germ and bran are often removed, leaving just the starchy endosperm
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REFINED CHO VS WHOLE GRAIN
Whole grains are higher than refined carbohydrates in fiber, vitamins, minerals, and other beneficial compounds
Whole grains take longer to digest
Choose foods that have a whole grain as the first item on the ingredient list on the food label

17. Recommended Carbohydrate Intake
Adequate daily intake of carbohydrate = 130 grams
Acceptable Macronutrient Distribution Range = 45–65% of total daily calories as carbohydrate
Limit intake of added sugars
Increase consumption of unrefined grains, fruits, vegetables, and legumes

18. Vitamins: Organic Micronutrients
Four vitamins are fat-soluble
(A, D, E, and K)
Nine vitamins are water-soluble
(C and the eight B-complex vitamins: thiamin, riboflavin, niacin, vitamin B-6, folate, vitamin B-12, biotin, and pantothenic acid)
Do NOT provide kcals!
Vitamins = organic (carbon-containing) substances needed in small amounts to help promote and regulate chemical reactions and processes in body cells.
Vitamins are abundant in fruits, vegetables, and grains; they are also added to some processed foods
If you consume too much or too little of a particular vitamin, characteristic symptoms of excess or deficiency can develop
Vitamins commonly lacking in the American diet:
Vitamin A
Vitamin C
Vitamin B-6
Vitamin E

19. Minerals: Inorganic Micronutrients
There are about 17 essential minerals:
Major minerals (those that the body needs in amounts exceeding 100 mg per day):
Calcium, phosphorus, magnesium, sodium, potassium, and chloride
Essential trace minerals:
Copper, fluoride, iodide, iron, selenium, and zinc
Minerals = inorganic (non-carbon-containing) compounds needed in small amounts for regulation, growth, and maintenance of body tissues and functions
If you consume too much or too little of a particular mineral, characteristic symptoms of excess or deficiency can develop
Minerals commonly lacking in the American diet:
Iron = low intake can cause anemia
Calcium = low intake linked to osteoporosis
Potassium = low intake linked to elevated blood pressure and bone mineral loss

20. Water: A Vital Component
Human body is composed of about 60% water; you can live only a few days without water
Foods and fluids you consume provide 80–90% of your daily water intake
Adequate intake?
Adequate intake to maintain hydration:
Women need to drink about 9 cups of fluid per day
Men need to drink about 13 cups of fluid per day
Drink in response to thirst; consume additional fluids for heavy exercise

21. Other Substances in Food: Fiber
Dietary fiber=non-digestible
Functional fiber=non-digestible
Total fiber=dietary fiber+functional fiber
Dietary fiber = nondigestible carbohydrates and lignin that are present naturally in plants
Functional fiber = nondigestible carbohydrates isolated from natural sources or synthesized in a lab and added to a food or supplement
Total fiber = dietary fiber + functional fiber

22. Types of Fiber Soluble (viscous) fiber Insoluble fiber
Sources of Fiber
Recommended intake?
Soluble (viscous) fiber = fiber that dissolves in water or is broken down by bacteria in the large intestine
Slows the body’s absorption of glucose
Binds cholesterol-containing compounds
Insoluble fiber = fiber that doesn’t dissolve in water
Makes feces bulkier and softer
Helps prevent constipation, hemorrhoids, and diverticulitis
Sources of Fiber:All plant foods contain fiber, but processing can remove it
Good sources of fiber:
Fruits (especially whole, unpeeled fruits)
Vegetables
Legumes
Oats (especially oat bran)
Whole grains and wheat bran
Psyllium (found in some cereals and laxatives)
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RECOMMENDED INTAKE
Women = 25 grams per day
Men = 38 grams per day
Americans currently consume about half this amount

23. Other Substances in Food: Antioxidants
Antioxidant = a substance that protects
Many fruits and vegetables are rich in antioxidants such as vitamin C, vitamin E, selenium, and carotenoids
Antioxidant = a substance that protects against the breakdown of body constituents by free radicals; actions include binding oxygen, donating electrons to free radicals, and repairing damage to molecules
Free radical = a chemically unstable, electron-seeking compound that can damage cell membranes and mutate genes in its search for electrons

24. Lecture Summary
List the six essential nutrients and describe their functions in the body.
List the acceptable macronutrient distribution ranges.
Explain the difference between the following:
Complete and incomplete proteins
Saturated, unsaturated, and trans fat
Simple and complex carbohydrates
Soluble and insoluble fiber
Explain the role of fiber and antioxidants in the body.