This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
1. Terminology 2. Introduction Nutrients & Calories 3. Characteristics of a sound diet 4. Results of a sound diet 5. Health & Malnutrition 6. Factors affecting longevity & food
choices
Terminology
Diet: The kind and amount of food consumed each day.
Food: Anything that nourishes the body.
Nourish: To keep alive.
Terminology
Nutrition: The study of how food keeps us alive. – Includes the ingestion,
digestion, absorption, assimilation, and excretion of food.
Nutritional Sciences: The study of nutrition including dietary components and metabolism.
• Nutrient: Molecular substances that are nourishing or that provide nourishment to cells and thus every multicellular component of the human organism.
• Essential: The body cannot make these nutrients, they must be consumed. Without an intake, specific deficiency signs and symptom occur.
• Nonessential: The body can make these nutrients. Without an intake, nutritional deficiency signs and symptom do not occur.
• Energy Producing: Produces Calories when metabolized by the body.
• Non-Energy Producing: Do not provide Calories but have other important functions.
Terminology Molecules to Cells to Organisms in
the Order of Life
1/20/12
2
Overview of the Nutrients
Nutrient Oxygen Carbon Hydrogen Nitrogen Minerals
Water X X
Carbohydrate X X X
Fat X X X
Protein X X X X
Vitamins X X X X*
Minerals X
* Some B vitamins contain Nitrogen
The Six Categories of Nutrients
Can be divided into two categories: • Energy Producing Nutrients
(Macronutrients) – Carbohydrates, Fats and Proteins
• The Kilocalorie (Calorie): – The unit used to measure
energy. – It is the amount of heat energy
required to raise one kilogram of water one degree Celsius (C) from 36o-37oC (actually a kilocalorie, Kcal or Calorie denoted with a capitol “C”).
Terminology Energy Producing Nutrients
* Fiber is a non-caloric carbohydrate
The Kilocalorie (Calorie)
§ How do we apply this definition to the energy applied to food?
§ By using a Bomb Calorimeter.
Bomb Calorimeter
1/20/12
3
Energy Production in the Body
• The ultimate fuel used in the body is a chemical called ATP
• ATP = Adenosine Tri-Phosphate • We capture the chemical energy
between the carbon-carbon bonds in Carbohydrate, Fat and Protein to form ATP
Nicknames: Energy Producing Nutrients
• Carbohydrates are the High Performance Fuel – Carbs are fast and best at making ATP
• Fats are the Low Level Fuel – Fats are very slow to produce ATP
• Proteins are the building blocks for growth and repair – Only under intense stress does protein
provide ATP – Loads of toxic waste is produced when
protein is over consumed
The Non-caloric Nutrients
What does non-caloric mean? • No ability to generate ATP • No Calorie value • Some non-caloric nutrients can be
essential for the body • Physiological failure or death
occurs if the nutrient is withheld from the diet
The Goal of Eating
• Food keeps us alive by providing Calories (energy) and Nutrients. The relationship between Calories and Nutrients is called:
• Nutrient Density: Refers to the amount of nutrients provided relative to the number of Calories. Foods with high nutrient density are nutritious.
Terminology Nutrient Density
Values shown are % DRI for a
moderately active adult woman
1 Large Potato vs 1 Small Order Fast Food Fries, both 210 Calories
1/20/12
4
Nutrient Density 1 cup plain yogurt vs ½ cup vanilla ice cream, both 130 Calories Nutrient Density
Characteristics of a Sound Diet Calorie Control: An appropriate amount of Calories
are eaten to maintain a healthy body weight. Adequacy: Essential nutrients, fiber, and energy
(Calories) are present in the diet. Balance: Food types complement one another in the
diet. Not any one nutrient or food type is overbearing.
Moderation: The diet does not contain an excess of unwanted substances.
Variety: Different foods are used for the same purpose in the diet.
Diet Results • Result of a sound diet:
– Health: The state of complete physical, mental, and social well-being; not just the absence of infirmity.
• Result of a poor diet: – Malnutrition: Impairment of health resulting
from deficiency, toxicity, or imbalance of nutrient intake or body utilization (includes over-nutrition and under-nutrition).
Health
Philosophical Statement about Health • Healthy lifestyle behaviors promote health, &
unhealthy lifestyle behaviors promote disease. Over long periods of time the health consequences can be realized. Therefore, even though a person may be “disease-free” at the moment, a person that lives an unhealthy lifestyle should not be labeled as a “healthy” person.
Factors Affecting Longevity
1. Diet • Poor diets promote degenerative
diseases/conditions: such as, cancer, heart disease, osteoporosis, diabetes, & obesity.
• Dietary factors like Fat, Sugar, Fiber, Sodium, Alcohol, & Calcium, function in the disease process.
1/20/12
5
Leading Causes of Death
Diet Related
Non-Diet Related
Alcohol Related
Dea
ths
per 1
00,0
00
Factors Affecting Longevity
2. Exercise (physical activity) • Promotes health by positively influencing
body weight/composition, metabolism, bone density, cognitive function, blood pressure, blood cholesterol, and the cardiovascular system.
• Strive for 60 minutes each day.
Factors Affecting Longevity
3. Other Factors • Smoking or tobacco use is a leading
contributor to death of Americans • Habits (lack of sleep, alcohol & drug
use, unsafe sex) • Chance (accidents) • Genetics
Factors Affecting Food Choices
1. Hunger: The Physiological need for food. The physical body sends signals indicating a need for food.
2. Satiety: The Physiological feedback mechanisms that terminate food intake.
3. Appetite: The Psychological desire for food. The brain sends signals indicating a desire for food because of sensory input like seeing, smelling, or thinking about food.
Factors Affecting Hunger, Appetite and Satiety
Factors Affecting Food Choices
4. Personal Preferences: The food likes and dislikes of an individual.
• Honey contains glucose, fructose & small amounts of other sugars.
• Animal foods usually provide mostly protein & fat.
• Milk & milk products also provide protein & varying amounts of fat.
How much carbohydrate do you need?
The Acceptable Macronutrient Distribution Range (AMDR) is:
≤ 25% of Calories from sugars
How much fiber do you need?
The dietary recommendation for fiber is 1.4 gram per 100 Calories consumed
Alcohol: Carbohydrate & Drug
• Provides 7 Calories/gram. • Is a carbohydrate related substance. • Lacks nutritional value. • Is a CNS depressant. • Is considered a drug. • Is commonly ingested. • One serving per day may reduce
dressings, cream cheese, olives, nuts & seeds are all examples of foods high in dietary fat.
• Try to chose healthy fats from plant sources, like those shown on the right.
Fatty Acid Composition of Common Fats
Essential Fatty Acids
• The body cannot make the essential fatty acids (EFAs).
• Linoleic Acid & Alpha-Linolenic Acid. • These EFAs are found in plant oils &
plant foods. • Deficiency characteristics develop
when they are lacking in the diet.
Essential Fatty Acids • The AMDR level for adults that will optimize
health are: – 5-10% of Calories from Linoleic Acid – 0.6-1.2% of Calories from Alpha-linolenic Acid
• Linoleic Acid is an omega 6 fatty acid. • Alpha-linolenic Acid is an omega 3 fatty acid.
Alpha-Linolenic Acid
COOH CH3 1
2 3
Linoleic Acid 3 COOH
CH3 1
2 4 5
6
Essential Fatty Acids Trans Fatty Acids Created in food
processing when PUFAs or MUFAs are partially hydrogenated.
1/20/12
4
Functions of Fat • Increases satiety value of a meal. • Improves texture, flavor & aroma of food. • Required for fat soluble vitamin absorption. • Provides the body’s major energy stores. • Cushions vital organs. • Is an essential structural component of cell
membranes. • Provides insulation.
Fat: Dietary Recommendations • 20-35% of total dietary Calories should
come from fat. This is the AMDR. <7% should come from SFA. Limit trans fatty
acids. • All excess Calories consumed whether from
carbohydrates, proteins, or fats are converted to fat & stored in fat cells.
• Fat is the storage form of energy in mammals.
Phospholipids (lecithin)
• Non-Energy Yield: 0 Calories per gram. Phospholipids are non-caloric lipid substances.
• Sources: Lecithin is found in egg yolk and soy products and is the most common phospholipid consumed in the diet.
Phospholipids (lecithin) Functions: 1. Phospholipids like lecithin
are emulsifiers that allow water soluble & fat soluble substances to mix (like oil & vinegar).
2. Lecithin provides choline which is a component of the neurochemical acetylcholine.
3. Phospholipids are used to make cell membranes.
Lecithin: A Phospholipid Actual
Structure of Lecithin
1/20/12
5
Cell Membrane Includes phospholipids, cholesterol, proteins.
Sterols Cholesterol is the most popular dietary sterol
Non-Energy Yield: Noncaloric, 0 Calories/gram
Sources of Cholesterol: 1. Exogenous: From outside the body.
Cholesterol is made by animals. It is only found in animal foods & byproducts.
2. Endogenous: Made inside the human body.
Exogenous Sources
• Egg yolk provides ~275 mg each. • Organ meats & crustaceans such as
crab, shrimp & lobster provide ~190 mg per 3 ounces.
• Much smaller amounts are in the fat portions of animal meats & products like milk.
Endogenous Sources • Cholesterol is a very important
molecule in the body. • Cholesterol is made inside the human
body, primarily in the liver, from SFA. • Usually about 1 gram (1,000
milligrams) of cholesterol per day is produced in the body.
• It is a very waxy substance.
Cholesterol is used to make … Cholesterol is used to make …
• Myelin sheath that covers nerve cells. • Cell membranes.
1/20/12
6
Cholesterol Recommendation • Cholesterol can be deposited in the
artery walls leading to plaque buildup & heart disease.
• To maintain heart health, the dietary recommendation is to limit intake to < 300 mg/day.
• To improve heart health, limit intake to < 200mg/day.
Summary • Fat/Lipid is an organic compound. • Fat/Lipid is categorized as triglycerides,
phospholipids, and sterols. • Triglycerides provide 9 Calories per gram. • Triglycerides contains fatty acids that are categorized
as SFA, MUFA, & PUFA. • There are 2 EFAs that are PUFAs. • Triglycerides have many important functions.
Summary • Consume 20-35% of Calories from fat & limit SFA
to <7% of Calories. • Phospholipids like lecithin, emulsify and help make
up cell membranes and acetylcholine. • Cholesterol is found in animal foods. It is not
essential and can be made in the liver. It has many important functions in the body but intake should be limited to less than 300 mg/day.
References for this presentation are the same as those for this topic found in module 1 of the textbook
The Vitamins • Some vitamins are essential. • Without an intake of, nutritional
deficiencies occur. • Vitamins are organic
compounds. • They contain the
element carbon. • All vitamins are non-
caloric.
The Vitamins • All vitamins are needed in tiny
amounts for cell metabolism
• microgram (µg, mcg, ug) or
As compared to gram amounts for carbohydrates, proteins and fats
• milligram (mg) amounts
Functions of Vitamins • In cell chemistry or metabolism.
• Enzymes are protein based molecules that catalyze chemical reactions (drive metabolism).
• Many enzymes require a partner called a cofactor or coenzyme to function.
• Vitamins & minerals can function as specific cofactors for specific enzymes.
Enzymes & Cofactors in Metabolism
Examples: The vitamin folate is a cofactor for the enzyme homocysteine transmethylase. The mineral selenium is a cofactor for the enzyme glutathione peroxidase.
2
Categories of Vitamins Fat vs Water Soluble
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Chemical structures are in appendix A
Categories of Vitamins Fat vs Water Soluble
The Water Soluble Vitamins
Chemical structures are in appendix A
Vitamins • Other compounds have vitamin activity in
animals, but deficiencies have not been shown in humans.
• The aforementioned vitamins are essential in human nutrition.
Minerals • Some minerals are essential. • Without an intake of, nutritional
deficiencies occur. • All minerals are elements. • All minerals are inorganic substances.
» this is because minerals are unique elements and are not compounds containing carbon.
Minerals • All minerals are non-caloric • All minerals are needed in tiny
amounts for cellular metabolism and structure – Microgram (µg) – Milligram (mg) amounts
As compared to gram amounts for carbohydrates, proteins, and fats
The Periodic Table of Elements
• Shows all the elements that are naturally found in the earth.
• Each element has unique physical properties such as melting point, crystalline structure, boiling point, and molecular weight.
• Some of the elements naturally found in earth are essential for the human body to function and are called minerals.
3
Periodic Table of the Elements Nutritional Application for Essential Minerals