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Nutrition
Important Historical Figures in relation to nutrition:
Justus von Liebig: 1832- significant contributions to the analysis of organic compounds. Studied
oils in bitter almonds
Antoine- Laurent Lavoisier: Major contributions to chemistry- Law of conservation of mass
Claude Bernard: French physiologist- studied the physiology of digestion, metabolism,
vasodilation, vasoconstriction
Emil Fischer: Organic chemist- Major contributions to our understanding of the structure of
organic molecules.
The Importance of Good Nutrition:
Good nutrition enhances your quality of life and helps you prevent disease. It provides you with the
calories and nutrients your body needs for maximum energy and wellness.
Nutrition: Process by which the body takes in and uses food
Nutrients: Substances in foods that your body needs to grow, to repair, and to provide energy
Calories: Units of heat that measure the energy used by the body and energy supplied to the body
by foods.
What influences your food choices?
1. Hunger and Appetite:
 Hunger: Natural need to eat and not starve.
 Appetite: A desire to eat.
2. Emotions:
 Stress, Anger, Happy, Sad, Boredom, etc,
3. Environment:
 Family and Friends
4. Cultural and Ethnic Background:
 Race, Religion, Heritage
5. Convenience and Cost:
 Where you live, On the go lifestyle, Family income
6. Advertising:
 Health messages, Influence your looks
6 GROUPS OF NUTRIENTS:
• Carbohydrates
• Proteins
• Fats
• Vitamins
• Minerals
• Water
Carbohydrates
Carbohydrates are the starches and sugars present in food. They are classified as either simple or
complex. Simple carbohydrates are sugars.
Examples include:
 glucose
 fructose
 lactose
Sucrose= ________+ ___________
Maltose=________+____________
Complex carbohydrates are starches.
Examples include:
• whole grains
• seeds
• legumes
Fiber is an indigestible complex carbohydrate that helps move waste through the digestive system.
Role of Carbohydrates:
• Body’s preferred source of energy.
• Body converts all carbohydrates to glucose, a simple sugar.
• Glucose is not used right away and it is stored as glycogen.
• Too many carbohydrates will cause the body to store the excess as fat.
Blood Sugar
• __________________= low blood sugar
• Blood sugar decreases to below normal levels.
• ___________________= high blood sugar
• Blood sugar increases to below normal levels.
• Body cannot make enough insulin
Proteins
Proteins are nutrients that help build and maintain body cells and tissues.
• Amino acids are the building blocks of proteins.
• There are 22 amino acids.
• We require 9 amino acids in our body= essential amino acids
Proteins are classified into two groups: complete and incomplete.
• Complete proteins contain amounts of all nine essential amino acids.
Sources include:
*Fish, meat, poultry, eggs, milk, cheese, yogurt, and many soybean products.
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Incomplete proteins lack one or more essential amino acids.
Sources include:
*Beans, peas, nuts, and whole grains.
Role of Proteins:
• Proteins have many functions:
• Help make new cells.
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Help make and repair tissues.
Help make enzymes, hormones, and antibodies.
Provide energy.
Enzymes:
 Proteins that act as catalysts in biochemical reactions of organisms
o = speed up or slow down reactions but never become part of the reacting
compounds or their production
 Thousands of enzymes are present in every cell
 They have a highly specific an specialized structure
 Examples:
o Digestive enzymes- amylase, maltase, protease, lipase
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Proteins are dependent on temperature; therefore, the function depends upon its
environment.
Proteins can become denatured- change of molecular shape due to temperature, pH, or
radiation.
Extreme conditions- fried egg (irreversible)
All humans function best at temperatures near 37 degrees however a stomach enzyme
functions best at a low pH while others need a neutral pH.
Fats
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Fats are a type of lipid, a fatty substance that do not dissolve in water.
The building blocks of fats are called fatty acids
Fatty Acids are classified as two types
Saturated:
• Animal fats and tropical oils
• High intake is associated with an increased risk of heart disease
• Unsaturated:
• Vegetable fats
• Associated with a reduced risk of heart disease
• Fatty acids that the body needs, but is unable to make are called essential fatty acids
• Transport vitamins A, D, E, and K
• Sources of linoleic acid- essential fatty acid that is needed for growth and healthy skin
• High intake of saturated fats is linked to increased cholesterol production
• Excess cholesterol can lead to an increased risk of heart disease
Cholesterol
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Cholesterol is a waxy, fat-like substance that’s found in all cells of the body.
Cholesterol helps to make hormones, vitamin D, and substances that help you digest foods.
Your body makes all the cholesterol it needs. However, cholesterol
also is found in some of the foods you eat.
Cholesterol travels through your bloodstream in small packages
called lipoproteins.
These packages are made of fat (lipid) on the inside and proteins on
the outside.
Two kinds of lipoproteins carry cholesterol throughout your body:
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low-density lipoproteins (LDL)
high-density lipoproteins (HDL).
1. LDL cholesterol - “bad” cholesterol.
• A high LDL level leads to a build-up of
cholesterol in your arteries.
2. HDL cholesterol - “good” cholesterol.
• Carries cholesterol from other parts of
your body back to your liver.
• Your liver removes the cholesterol from your body.
Vitamins are compounds that help regulate many vital body processes that include:
1.Digestion
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2. Absorption
3. Metabolism
4. Circulation
Water Soluble:
Water-soluble vitamins dissolve in water and pass easily into the blood during digestion.
Body does not store so they need to be replenished regularly.
Includes vitamins C, B1 ,B2, Niacin, B6, Folic acid, and B12.
2. Fat-soluble vitamins are absorbed, stored, and
transported in fat.
 Your body stores these vitamins in your fatty tissue, liver,
and kidneys.
 Excess buildup can be toxic.
 These include vitamins A, D, E, and K.
Minerals:
Minerals are substances that the body cannot manufacture but are needed for forming healthy bones
and teeth and regulating many vital body processes.
Important minerals include:
 Calcium
 Phosphorus
 Magnesium
 Iron
Water helps to maintain many bodily functions.
 Lubricates your joints and mucous membranes.
o Enables you to swallow and digest foods.
 Absorb other nutrients, and eliminate wastes.
o Perspiration helps maintain normal body temperature.
 Water makes up around 65% of the body.
 It’s important to drink at least 8 cups of water a day to maintain health.