Energy from Food
Energy from Nutrients

Three nutrients-carbohydrates, proteins, fats provide energy the body can use.

Energy is the capacity to do work or produce heat. The body uses energy from these
nutrients to grow, move, and create heat to maintain a steady temperature.

Carbohydrates supply the body with one of its main fuels called glucose.

Glucose is a simple form of carbohydrate which serves as the body’s sugar. The brain
and nervous system depend almost entirely on glucose for energy to think, trigger
movement, and send messages between tissues.

Fat supplies fatty acids-which are building blocks of fat that supply energy fuel for
most of the body’s cells. The muscles including the heart muscle, rely heavily on fatty
acids to fuel physical activity and movement.
Energy from Nutrients

Protein supplies amino acids- which are building blocks of protein normally used to
build tissues or under some conditions burned as energy.

In difficult situations such as starvation or severe stress the body can burn amino acids
from protein for fuel at a much greater rate than in normal times.

Alcohol also provides calories, but is not a nutrient. Alcohol does not help the body in
any way but is a toxin or poison that the body can only tolerate in small amounts.

Calorie- is a unit used to measure energy. If you consume more carbohydrates, fat, and
proteins than you need than these nutrients will be stored in your body mostly as fat.

Note calories are listed as per gram of carbohydrates, fats, and proteins.

A gram is a unit of weight, about 1/28th of an ounce. Vitamins and minerals are often
measured in grams or milligrams.
Digestion

A better choice is a meal that provides
carbohydrates, fats, and proteins in the
right amounts.

The carbohydrates in the meal provide
a quick source of glucose energy in the
form of calories.

The fat in the meal slows down
digestion- which means the breaking
down of food into nutrients the body
can use.

This makes the glucose last longer and
the protein helps make you feel fuller
for longer periods of time.
Carbohydrates

Carbohydrates are important in any diet
because they have starch, fiber, and
sugars.

Starch- is the main carbohydrate in
grains and vegetables. It provides
glucose which the body uses. The brain
needs glucose to perform at its best.

Fruits and vegetables also provide the
brain with glucose from the sugars in it.

The body stores extra energy in two
forms: glucose and fat.
Carbohydrates

Glycogen-is the form in which the liver and muscles store glucose. Fat is stored mostly
under the skin and in the abdomen.

Within seconds of eating carbohydrates, glucose flows into your blood. Your liver and
muscle cells gather up all the glucose they can hold and store it as glycogen. If more
glucose still flows in, the liver will convert it to fat and the fat cells in the fat tissue
store it.

Hypothalamus-a brain regulatory center. It sends out signals hunger signals when blood
glucose levels get too low. If you don’t eat the body starts to use its four hour worth
supply of glycogen stored in your liver to provide glucose.
Fiber

Fiber is a carbohydrate, but it is not
digestible by human beings. Fiber
provides very few calories. However it
helps maintain the health of the
digestive tract.

The body needs about 25 grams of fiber
each day to remain healthy.

Most types of fiber move through the
digestive tract almost unchanged.

Fiber aids in the digestion by making
the digestive tract contents (stool) soft
and bulky.
Fiber

Fiber binds with cholesterol and carries it out of the body in stool. It reduces blood
cholesterol and the risk of heart disease.

Fiber helps balance blood glucose and helps control the most common form of the
disease diabetes.

Some fibers bind cancer causing agents in the digestive tract, reducing the risk of
cancer.

Fiber also helps control body fat and it is very hard for a person to gain weight when
they are on a diet of high fiber intake.

Choose whole grains, whole fruits and vegetables. Eat these foods either lightly cooked
or raw.
Sugars

Sugars- carbohydrates found both in foods and in the body. All sugars are chemically
similar to the sugar called glucose. They can be converted to glucose in the body.

Glucose- also known as blood sugar or the body’s fuel.

Fructose- the natural sugar in fruits and honey.

Sucrose- known as table sugar.

Lactose- the natural sugar in milk.

In foods, all four sugars are delivered in diluted form mostly from fruits, vegetables,
and milk.
Sugar

Some of them are also delivered in the
concentrated form as sweeteners; table
sugar, brown sugar, corn syrup, and
molasses.

Any ingredient that ends in ose has
sugar in it.

Added sugars- sugars and syrups added
to a food for any purpose, such as to
add sweetness.

Empty calories- foods that contribute a
lot of energy (calories) but too little
nutrients.
Fats

Fat supplies most of the body’s fuel. It
also transports fat-soluble vitamins.

Fat can be stored, it serves as a reserve
supply of energy. Ft is stored in a layer
of cells beneath the skin, in many
padded areas such as the abdomen and
elsewhere.

Pads of fat help insulate the body and
protects it from cold temperatures. Pads
of fat also cushion the body organs,
protecting them from shocks and
bruises.
Forms of Fats

The fats come in two forms saturated fat and unsaturated fat.

Saturated fats- are fats associated strongly with heart disease and artery disease.

Unsaturated fats- are less associated with heart disease.

Polyunsaturated fats- is a type of unsaturated fat in a heart healthy diet.

People who are developing or who have heart and artery disease it is very important to
switch from saturated fat to unsaturated fat in foods.

Saturated fats come mainly from animal sources including meat fats, whole milk,
butter, and cream. They tend to be solid at room temperature. A few plant oils are high
in saturated fat such as coconut oil and palm kernel oil.

Unsaturated fats come primarily from vegetable oils. They include olive oil, corn oil,
and canola oil.
Fats and Cholesterol

Fish oil- a polyunsaturated fat from certain fish, thought to be necessary for health. It is
an animal fat but is polyunsaturated.

Trans fats- are a type of fat that forms when polyunsaturated oils are processed. These
trans fats damage heart health as do saturated fats.

Cholesterol- a type of fat made by the body from unsaturated fat. The body makes some
cholesterol from other fats in the body because cells need it to function properly.

Too much cholesterol is linked to heart disease. Also it cause build up in the arteries and
increases the risk of heart attacks and strokes.

People trying to lower their cholesterol need to lower their intake of cholesterol and
limit their intake of saturated fats.
Proteins

Proteins are body’s machinery-they do
the cells work.

Amino acids are the building blocks of
proteins. A set of 20 different amino
acids form proteins.

Your body can make amino acids for
itself.

Essential amino acids- are amino acids
that the body can’t make for itself and
must be gotten from food.
Proteins

Protein is found in meats, fish, poultry, eggs, cheese, milk, and plant foods such as
grains and beans.

Teens may receive more than enough daily protein from one egg, 3 cups of milk, and an
assortment of fruits and vegetables without a single serving of meat.

Vegetarians-people who omit meat, fish, and poultry from their diet. They can easily
make it up with grains, legumes, seeds and nuts, and vegetables.

Vegetarians must eat a variety of them everyday to receive to get all of the essential
amino acids.

Vitamin B12 is found only in meats, poultry, fish, eggs, and milk. Vegetarians who only
eat food from plants must rely on vitamin B12 fortified foods such as soy milk,
breakfast cereals, or take a supplement.
Protein

Vegetarians also must make sure they are
getting enough vitamin D and calcium.
Soy milk, leafy green vegetables also
have protein.

Iron and vitamin C are also important
and can be found in fruits and vegetables.
Iron can be found in meat and poultry.

A person who does not consume enough
protein can have their body waste away
and left defenseless against disease.

This happens to neglected and homeless
children, sick people in hospitals, and
substance abusers.
Vitamins

Supplement- is a pill, powder, liquid, or
the like containing only nutrients.

Deficiency- too little of a nutrient in the
body.

Fat-soluble- vitamins are able to dissolve
in fat and tend to remain in the body. Fatsoluble vitamins tend to remain in the
body and can reach dangerous levels if a
person takes too much of them.

Water-soluble- are able to travel in the
body’s watery fluids and leave the body
readily through urine. You need to
regularly replace the vitamins that you
lose.
Vitamins

Vitamin A is well known in its role in vision. Each year half a million children go blind
from a deficiency in this vitamin.

Night blindness- slow recovery of vision after flashes of bright light at nigh. As vitamin
A deficiency grows worse, it leads to permanent blindness.

Vitamin A helps the body fight infections and maintains healthy skin and promotes
growth.

Beta-carotene- is an orange vegetable pigment that the body can change into the active
form of Vitamin A.

Antioxidant-is a substance that defends the body against destructive compounds.

Free radicals-are compounds that trigger damaging chain reactions in the cells of the
body. The damage may promote cancer or heart disease.
Vitamins

Vitamin E- is an antioxidant nutrient. People who eat plenty of vitamin E rich foods
have lower rates of heart disease.

Thiamin-is a typical water soluble vitamin. It helps the body use energy from other
nutrients such as carbohydrates. It also helps release energy from carbohydrates, fats,
and proteins.

Folate and Vitamin B12- they work together but are found in different foods.

Folate is found in leafy green vegetables. While B12 is found in foods that come from
animals such as meats and milk.

Folate deficiency causes anemia, weakened immunity and abnormal digestion.

B12 deficiency causes anemia and abnormal nerve and muscle function.
Minerals

Calcium is the most abundant mineral
in the body and is mostly stored in the
bones and teeth.

A deficiency of calcium will cause the
strength of bones to be greatly
impaired.

Osteoporosis- a disease of gradual bone
loss, can cripple a person later in life.

If you can’t drink milk, you can have
almonds, canned sardines (with bones),
leafy greens broccoli, beans, and some
orange juice does have calcium.
Minerals

Iron is present in every cell in the body and is the oxygen carrier for the body.

Anemia- reduced number or size of the red blood cells. With too few red blood cells a person
will have anemia and grow tired and weak quickly.

Electrolytes-minerals that dissolve in body fluids and carry electrical charges. They help
maintain the proper balance of fluids in the body.

Salt-is a compound made of minerals that, in water, dissolve and form electrolytes.

Hypertension-high blood pressure.

Water is a major substance of which bodies are made. 60% of your body’s weight is water.

Water carries nutrients, waste, oxygen, and other materials from place to place in the body.

Urine-fluid waste removed from the body by the kidneys. You must replace all of the water
that you lose.