the basics of nutrition. “you are what you eat” food is your body’s fuel food is eaten ◦...
Post on 14-Dec-2015
218 Views
Preview:
TRANSCRIPT
Chapter 3 – How Nutrients Become
YouThe Basics of Nutrition
“You are what you eat” Food is your body’s fuel Food is eaten
◦ It is broken down into simpler elements◦ Energy is released and nutrients are used to help
build, repair, and maintain body cells◦ By-products are discarded as waste
The Basic Truth of Nutrition
These substances are best obtained from the food you eat
The body needs elements from all 6 groups in order to function properly and maintain good health◦ Carbohydrates◦ Fats◦ Proteins◦ Vitamins◦ Minerals◦ Water
There Are 6 Nutrient Groups
Where do they fit?◦ Nectarine◦ Wheat bread◦ Trail mix◦ Water
Why wouldn’t an unlimited supply of only one of these foods sustain life?
Variety Is Key
I know, I know – who wants to learn chemistry in HCR???
To understand the basics of nutrition, there has to be some understanding of basic chemistry – SORRY!
No worries – we won’t get too crazy with it
The Chemistry of Nutrition ()
Your body and the foods you eat are composed of chemical elements
Elements are the simplest substances from which all matter is formed◦ An atom is the smallest part of an element
A molecule is the smallest amount of a substance that has all the characteristics of the substance◦ Molecules are 2 or more atoms bonded together
The Chemistry of Nutrition
The atoms in a molecule may be all the same element, or they may be different elements
When atoms of different elements bond together, they form compounds
The Chemistry of Nutrition
5 of the basic nutrient groups are compounds (combination of different elements)◦ Carbohydrates◦ Fats◦ Proteins◦ Vitamins◦ Water
1 basic nutrient group is elements (simplest substance)◦ Minerals
The Chemistry of Nutrition
The essential nutrients from food are used to◦ Build and repair body tissues◦ Regulate all body processes◦ Provide energy
When provided with the proper nutrients, your body can perform all of these functions in harmony, which optimizes health, wellness, and performance
Functions of Nutrients
The body is made up of billions of cells◦ Cells divide, producing 2 new cells each time,
which accounts for your growth◦ New cells also repair damaged body tissues and
replace old cells All cells are formed with materials that
come from food Therefore, your body needs proper amounts
of nutrients to help make new cells
Building and Repairing Body Tissues
Periods of rapid growth require greater amounts of nutrients◦ Pregnancy◦ Infancy◦ Adolescence◦ Illness/injury recovery
Lacking proper nutrients during these periods can negatively affect growth potential, strength, health, healing, learning abilities, and behavior patterns
Building and Repairing Body Tissues
Mood? Attitude? Thinking? Physical performance?
How Does Hunger Affect Your:
The proper amounts and types of nutrients keep body processes running smoothly
Examples of body processes that rely on nutritional components◦ Circulation of body fluids◦ Maintaining the correct acid-base level in the
blood◦ Digestion◦ Absorption◦ Metabolism
Regulate Body Processes
Food is a source of energy for performance The quality of the food you eat affects how
your body will run The more active you are, the more energy
you will need to fuel your body processes
Provide Energy
Chemical reactions that take place in your cells release energy from nutrients that you get from food◦ Carbohydrates and fats are the main nutrients
used for energy◦ Proteins can be used, but the body prefers to save
them for other vital functions Vitamins, minerals, and water do not
provide energy, but the body needs them to help regulate the release of energy from carbs, fats, and proteins
Provide Energy
Measured in units called kilocalories (kcal) Commonly known as calories Only certain nutrients provide energy
◦ 1 gram of carbohydrate = 4 kcal of energy◦ 1 gram of fat = 9 kcal of energy◦ 1 gram of protein = 4 kcal of energy
Water, vitamins, and minerals do not yield energy, and therefore do not have a calorie content
The Energy Value of Food
Alcohol does have a calorie content◦ 1 gram of alcohol = 7 kcal of energy
It is not considered a nutrient because:◦ It does not promote growth (it inhibits)◦ It does not maintain cells (it destroys)◦ It does not repair tissues (it inhibits healing)
Determining Energy Values
Alcohol
The process by which your body breaks down food, and the nutrients in food, into simpler substances◦ The blood can carry these simpler substances to the cells
for use in growth, repair, and maintenance Digestion occurs throughout the digestive system
through mechanical and chemical means◦ Mechanical digestion – occurs when food is crushed and
churned◦ Chemical digestion – occurs when food is mixed with acids
and enzymes Enzyme – a type of protein produced by cells that cause specific
chemical reactions In digestion, they cause food particles to break apart into
simpler substances
Digestion
The muscular tube through which food passes from the mouth to the anus
Roughly 25-30 feet in length Each section has different functions Mouth → esophagus → stomach → small
intestine → large intestine
Pg. 49
Gastrointestinal Tract (GI Tract)
Mastication (chewing) is the1st step in digestion
Important mechanical digestive process as chewed food is broken down more easily by the body
Food is mixed with saliva in the mouth, which helps to moisten, soften, and dissolve food◦ Included in saliva is salivary amylase, an enzyme
which helps to break down starches
Mouth
Passageway from mouth to stomach About 10 inches long Food moves along this passageway through
a series of muscular squeezing actions called peristalsis
Involuntary muscle action that is part of mechanical digestion
Esophagus
The stomach produces gastric juices to aid in digestion◦ Made up of acids, enzymes, and mucus◦ Acids and enzymes break down food, and mucus softens
and lubricates chyme The gastric juices mix with the chewed food to form
chyme The stomach can typically hold about a quart of
food Food generally stays in the stomach for 2-3 hours,
depending on the type of food◦ Liquids leave first◦ Fats leave last
Stomach
About 95% of digestion takes place here Has 3 sections, and is roughly 20 feet in
length and 1 inch in diameter Takes food about 5-14 hours to move
through the small intestine through peristalsis action
The small intestine is aided by other organs during digestion◦ Pancreas – adds digestive enzymes◦ Liver – adds bile for breaking down fats
*Nutrient Digestion in the Small Intestine
Small Intestine
Also known as the colon Main job is to reabsorb water Very little digestion occurs here About 5-6 feet long Chyme stays in the colon for 1-3 days
before elimination Solid wastes that result from digestion are
eliminated as feces *Food Breakdown
Large Intestine
Absorption is the passage of nutrients from the digestive tract into the circulatory or the lymphatic system◦ Circulatory system – amino acids, monosaccharides,
minerals, and most vitamins◦ Lymphatic system – nutrients from fats
Most nutrients pass through the walls of the small intestine
The small intestine is lined with tiny, finger-like projections called villi ◦ Villi increase the surface area of the small intestine
and aid in absorption of nutrients
Absorption of Nutrients
Intestinal Villi
Once digestion and absorption have taken place, the circulatory system carries the nutrients to individual cells
Metabolism is all the chemical changes that occur as cells produce energy and materials needed to sustain life◦ Cells break down nutrients to release energy,
which is stored in the muscles as ATP◦ The waste products created through cell
metabolism are eliminated through the kidneys, lungs, and skin
Metabolism
Eating Habits Affect Digestion◦ Don’t eat too much or too little◦ Eat a variety of foods in order to get all of the
required nutrients◦ Include high-fiber foods to provide bulk and aid in
removing toxins◦ Foods high in fat will take longer to digest as fats
are the last nutrient component to leave the stomach
Factors That Affect Digestion and Absorption
Emotions◦ Fear, anger, and tension can lead to digestive
difficulties◦ Reducing stress and tension during mealtimes will
allow for better absorption of nutrients
Factors That Affect Digestion and Absorption
Food Allergies◦ A food allergy is a reaction of the immune system to
certain proteins found in food◦ The immune system protects the body from
invaders by forming antibodies◦ When you are allergic to a food, your body releases
antibodies in response to that food, leading to allergy symptoms
◦ These symptoms can include, but are not limited to, vomiting, intestinal distress, rashes, and swelling
This is different from a food sensitivity, such as lactose intolerance
Factors That Affect Digestion and Absorption
Factors That Affect Digestion and Absorption Physical Activity
◦ Aids digestion and metabolism
◦ Stimulates a healthy appetite and strengthens the muscles of the internal organs
◦ Helps move food through the GI tract
◦ Reduces stress
A nutritious diet can help to avoid or manage most digestive disorders
Some disorders require medical treatment in order to make certain that all required nutrients make it to the cells in order to maintain life
Digestive Disorders
Diarrhea◦ Frequent expulsion of watery feces◦ Causes food to move through the digestive
system too quickly for nutrients to be absorbed◦ Also leads to loss of body fluids as the food moves
too quickly through the large intestine for the water to be reabsorbed
Digestive Disorders
Constipation◦ Occurs when chyme moves too slowly through the
large intestine, leading to the reabsorption of too much water
◦ Causes the feces to become too hard and dry, which can lead to painful elimination and hemorrhoids
◦ Often caused by erratic eating habits, low fiber intake, lack of physical activity, and inadequate fluid intake
Digestive Disorders
Indigestion◦ Difficulty in digesting food◦ Can be caused by stress, eating too much or
eating too fast, or eating particular foods◦ Can include gas, stomach cramps, and nausea
Digestive Disorders
Heartburn◦ A burning pain in the middle of the chest caused
by stomach acid flowing back into the esophagus◦ Can be reduced by avoiding acidic foods, stress,
lying down right after eating, and taking antacids
Digestive Disorders
Ulcer◦ An open sore in the lining of the stomach or small
intestine caused by bacterium◦ Risk is increased by stress, heredity, alcohol use,
and aspirin abuse◦ Usually treated with antibiotics, as well as
decreasing stress, alcohol, caffeine, and tobacco use
Digestive Disorders
Gallstones◦ Small crystals that form from bile in the
gallbladder◦ These stones block the release of bile into the
small intestine, causing pain and slowing the digestion of fats
◦ Treatment includes a diet low in fats, and often requires surgery to remove the gallbladder
Digestive Disorders
Diverticulosis◦ The formation of abnormal pouches in the
intestinal wall◦ Can occur when the intestinal muscles become
weak, such as when a diet is low in fiber◦ These pouches can become inflamed, leading to a
painful condition called diverticulitis
◦ *What Could Be Wrong
◦ *Digestive Disorders
Digestive Disorders
top related