Chapter 5 Understanding Nutrition and Your Diet
Principles of Personal Health
I. Types and Sources of Nutrients
A. Introduction
1. The body relies on seven nutrients
2. Calories- Unit measuring the energy value of food or physical activity
B. Carbohydrates
1. The body’s primary source of energy
2. Contain four calories per gram
3. We should get 60% of our calories from carbohydrates (50% from starches & 10% from sugars
4. Three forms of carbohydrates:
a. Monosaccharides- Four forms:
~Glucose
~Fructose
~Galactose
~Mannose
b. Disaccharides
~Most widely recognized monosaccharide (Sugar)
~The greatest problem with excess sugar intake is
~increased dental problems
~Much of the sugar we consume is hidden - ketchup,
~salad dressing, meat products, canned products and
~vegetables
c. Polysaccharides (better known as starches)
~Long chains of glucose units
~Found in vegetables, fruits, and grains
~Fiber is also a polysaccharide
C. Fats
1. Provide a concentrated form of energy (9 calories per gram)
2. Helps give our foods satiety
3. Satiety- A feeling of no longer being hungry
4. Carries fat-soluble vitamins (A, D, E, & K)
5. Insulates the body and helps it retain heat
6. Examples: butter and salad oils
7. Most of the fat we eat is hidden - put into the food during preparation
8. No more than 25% to 30% of our calories should come from fat
9. Medical opinion advises against limiting fats in the diets of children younger than two
10. Three forms of fats:
a. Saturated fats
~Need to be limited
~Replacement of saturated fats with monounsaturated and polyunsaturated fats
b. monounsaturated and polyunsaturated fats
~Appear to lower blood cholesterol levels reducing the risk of heart disease
~Omega-3 fatty acid is a polyunsaturated fat that may be beneficial to the body (fresh fish: tuna, salmon, sardines)
~No major health organization has recommended supplemental omega-3
11. Tropical Oils
a. Saturated fats elevate blood cholesterol levels increasing the chance of heart disease
b. The tropical oils contain much higher percentages of saturated fats (Coconut & palm)
12. Cholesterol
a. A high level of cholesterol is a risk factor for developing cardiovascular disease
b. Cholesterol- A primary form of fat found in the blood
c. Intake of cholesterol should be restricted to 300 mg or less per day
13. Low-fat foods
a. These foods may still be high in calories
b. Should not be consumed in large amounts
14. Fat-Free Substitutes
a. Contain no cholesterol and have 80% fewer calories than similar products
b. Have side effects for some people
D. Proteins (four calories per gram)
1. Proteins- Compounds composed of chains of amino acids
2. Amino acids- The building blocks of protein
3. The body obtains amino acids from two sources:
a. breaking down protein from food
b. manufacturing its own
4. Essential amino acids- Those which cannot be built by the body
5. Nonessential amino acids Those which the body can produce
6. Complete proteins- Those which contain all nine essential amino acids (of animal origin)
7. Incomplete proteins- Those which do not contain all the essential amino acids (of plant origin)
8. Protein serves to promote growth and maintenance of body tissue
9. 15% of our calorie intake should be from protein
E. Vitamins (Do not provide calories)
1. Organic compounds required in small amounts for nomral growth
2. Help initiate a wide variety of body responses
3. Water soluble- Capable of being dissolved in water (B-Complex & C)
4. Fat soluble- Capable of being dissolved in fat (A, D, E, & K)
5. Fat soluble vitamins hold the potential for toxicity if taken in excess
6. Most toxicity results from the use of supplements
7. The best way to get vitamins is through a variety of foods
8. Special circumstances may require supplementation: pregnancy, infancy, or health problem
9. Folic acid before and during pregnancy can reduce the incidence of birth defects
F. Minerals
1. Nearly 5% of the body is composed of minerals
2. Critical in the regulation of a number of body processes
3. 21 minerals are essential for human health
4. Macronutrients- minerals that are needed in high amounts: calcium, sodium, potassium
5. Micronutrients- minerals needed in small amounts: zinc, iron, copper
6. The safest way to receive minerals is through a balanced diet
G. Water
1. The most essential nutrient
2. Dehydration- A depletion of fluids from the body can lead to death
3. More than half the body’s weight comes from water
4. Water is a medium for nutrient and waste transport, temperature control and plays a role in nearly all body processes
5. Adults require about six to ten glasses a day
6. Beverages that tend to dehydrate the body: tea, coffee, and alcohol
7. People also obtain fluids from fruits, vegetables, juices, milk, and noncaffeinated soft drinks
H. Fiber
1. Fiber is an important component of sound nutrition
2. Fiber is plant material that is not digested by humans
3. Insoluble fibers- Those that can absorb water from the intestinal tract
4. Soluble fibers- Binds to cholesterol helping to remove it
I. The Absorption of Nutrients
1. The first 18 inches of the small intestine is the most active site for absorption
2. Any injury or disease to this location could harm nutritinal status
II. The Food Groups
A. The most effective way to obtain all nutrients is to eat a balanced diet
B. The Food Pyramid (Pg. 132) outlines five groups and an additional group (fats, oils, and sweets)
1. Fruits (Two to four servings daily)
a. May play a role n the prevention of certain forms of cancer
b. At least one serving high in vitamin C is needed daily
2. Vegetables (Three to five servings daily)
a. May also be important in the prevention of some cancers
3. Milk, Cheese, and Yogurt (Two to Three servings daily)
a. Two primary benefits: Protein and Calcium
b. Low-fat milk products are recommended
4. Meat, Poultry, Fish, Eggs, Dry Beans, and Nuts (Four ounces daily)
a. Meats include all red meat, fish, and poultry
b. Meat substitutes: cheese, dried peas and beans, peanut butter
c. Poultry and fish are lower in overall fat than red meats
5. Breads, Cereals, Rice, and Pasta (Six to Eleven servings daily)
a. Enriched bread or cereal are recommended
b. Enriched- The process of returning some of the nutritional elements to foods
6. Fats, Oils, and Sweets (Use sparingly)
a. Beer, butter, candy, colas, cookies, etc.
b. Contribute little to healthful nutrition
c. Have significant amounts of salt and fat
d. Can be part of a healthy diet if eaten sparingly
III. Fast Foods
A. Nutritional value of fast foods can vary considerably
B. Fat density- The percentage of a food’s total calories that are derived from fat
C. Fast-food restaurants have broadened their menus to include
IV. Phytochemicals
A. Components that may be able to deactivate carcinogens and provide antioxidants
B. May play an important role in reducing the risk of cancer
V. Food Additives
A. Food additives- Chemical compounds that are added to our food supply
B. If we wish to live in an urban setting, we have to accept the presence of food additives
C. Chemicals are added to food for several reasons:
1. To maintain the nutritional value of food
2. To maintain the food’s freshness
3. To control the texture, acidity, and thickness
4. To enhance flavor
VI. Food Labels
A. Manufacturers are required to provide nutritional information (labels) on food products
B. The FDA has developed new labeling regulations
VII. Guidelines for Dietary Health
A. Guidelines are directed to healthy Americans two years and older
B. Specific Guidelines:
1. Eat a variety of foods
2. Balance the food you eat with physical activity - Maintain/Improve your weight
3. Choose a diet with plenty of grain products, vegetables, and fruits
4. Choose a diet low in fat, saturated fat, and cholesterol
5. Choose a diet moderate in sugars
6. Choose a diet moderate in salt and sodium
7. If you drink alcoholic beverages, do so in moderation
VIII. Recommended Dietary Adjustments
A. Dietary practices established during the college years may continue throughout life
B. Additional Milk Consumption
1. It is recommended that adult women increase their dairy product intake to provide needed calcium
2. Excessive caloric and fat intake can be controlled by using low-fat products
3. Calcium supplements are an alternative
C. Additional Protein-Rich Sources
1. Premenopausal women often need to replace iron lost during menstruation
2. Another way to maintain iron is to include appropriate vegetables, fruits, and grain
3. Iron supplements may help provide needed iron for those who eat little or no red meat
4. Consult a physician before taking iron supplements
D. Additional Vitamins C and A
1. Vitamin C will assist in the absorption of iron
2. Larger servings of fruits and vegetables are recommended
E. Additional Grain Product Consumption
1. 60% of our total calories should come from carbohydrates
F. Moderate Alcohol Consumption
1. Heavy use of alcoholic beverages can seriously harm nutritional status
2. Overuse of alcohol can rob your body of its ability to absorb nutrients successfully
3. Alcohol consumption is associated with a wide variety of diseases: Cancer & Liver complications
G. Nutrient Density
1. Foods with a high nutrient density are better choices than those that supply only empty calories
IX. Vegetarian Diets
A. Semivegetarianism- A diet that significantly reduces but does not eliminate meat consumption
B. A vegetarian diet relies on plant sources for most of the nutrients
C. Three vegetarian diets:
1. Ovolactovegetarian Diet
a. Excludes all meat but does allow the consumption of eggs and dairy products
b. Meatlike products are available in supermarkets
c. Concerns associated with Ovolactovegetarian diets: zinc deficiency, overuse of food supplements
2. Lactovegetarian and Ovovegetarian Diets
a. Dairy products in their diet but no other animal products
3. Vegan Vegetarian Diet
a. Meat and other animal products are removed from the diet
b. Several difficulties can arise:
~Obtaining all essential amino acids
~Maintaining the necessary intake of vitamin B12
~Maintaining adequate intakes of iron, zinc, and calcium
~Vitamin D deficiencies
~Insufficient caloric intake
X. High-Risk Dietary Practices
A. Unbalanced and Fad Diets
1. A diet lacking variety generally cannot provide you with all of the needed nutrients
2. College students tend to adopt unbalanced diets more frequently than other adults
XI. Nutrition and the Older Adult
A. Nutritional needs change as adults age
B. Older adults can find food less tasteful and harder to chew
C. Lowering of the body’s basal metabolism influences dietary patterns of older adults
D. Loss of appetite in many elderly people
XII. International Nutritional Concerns
A. The main concern in many areas of the world is limited quantity and quality of food.
B. To increase the availability of food to countries without the ability to produce it:
1. Increase the yield of land under cultivation
2. Increase the amount of land under cultivation
3. Increase animal production
4. Use water more efficiently for the production of food
5. Develop unconventional foods
6. Improve nutritional practices thorough education
Copyright © 1998 by Allen
Mooneyhan. All rights reserved.
Reproduction or redistribution prohibited.