Download what is energy

ENERGY
Ch.12
WHAT IS ENERGY
Ability to do work.
Types of energy:



Chemical
Mechanical
Heat
Cannot create or destroy it; can only
change form
http://safari.pisd.edu/?a=47764&ch=2&d=00267AA
ENERGY IN
CALORIES
3 WAYS TO GET ENERGY



CARBOHYDRATES
FATS
PROTEINS
(what your body prefers)
HOW DO I KNOW HOW MUCH
ENERGY IS IN MY FOOD?
A FOODS CALORIE VALUE IS A MEASURE
OF THE HEAT IT GIVES OFF WHEN IT
IS BURNED IN A
BOMB CALORIMETER!
THE ENERGY IT TAKES TO RAISE WATER
1 DEGREE CELISIUS = 1 CALORIE
http://safari.pisd.edu/?a=47771&ch=3&d=00308AA
Calorie Density
CONCENTRATION OF ENERGY IN FOOD
DIVIDE GRAMS INTO CALORIES
THE MORE WATER CONTENT OF
FOOD….THE LESS CALORIE DENSE
(WATER DOESN’T BURN)
ENERGY OUT
Three reasons you need energy.
 Basal Metabolism
 Physical Activity
 Thermic Effect of Food
ALL THESE added TOGETHER
EQUALS
=
THE TOTAL AMOUNT OF ENERGY (CALORIES) YOU
NEED DAILY
BASAL METABOLISM
60% of your calories are used for this function
Basal Metabolism is the amount of energy needed to
support the operations of all internal body systems
What are some of the ways your body uses basal
metabolism?






Breathing
Blood Circulation
Maintaining Nerve Activity
Secreting Hormones
Maintaining Body Temperature
Make new cells
BMR
Basal Metabolic Rate is the rate at
which the body uses energy for basal
metabolism.
Women require approximately .4 calorie
per pound, per hour
Men require .5 calorie per pound, per
hour
What is your basal energy need?
WHAT EFFECTS BMR?
Body structure
Body composition – percentage of different tissues in the body;
 Fat
 Muscle
 Bone
Gender
Age
Body Temperature
Diet
Disease

Thyroxine
Physical Activity
Need energy to move your muscles
Need energy for extra breathes and
circulation while working or exercising
Energy output varies depending on body size.
The larger the body, the more energy is
needed.
Actual amount of movement of
muscles will affect total energy
output
PHYSICAL ACTIVITY
30% of your calories are used for
this function
Sleep

You burn 60 calories per hour
Sedentary Activities

Reading, Eating, Watching TV, Playing cards, Using a
computer
 You burn 80-100 calories per hour (average 90)
Light Activities

Cooking, Doing Dishes, Ironing, Walking slowly
 You burn 110-160 calories per hour (average 135)
Physical Activity cont’d
Moderate Activities
 Walking, Making a bed, light gardening, Standing
activities requiring arm movement
 You burn 170-240 calories per hour (average 205)
Vigorous Activities
 Walking fast, Golfing, Yard Work
 You burn 250-350 calories per hour (average 300)
Strenuous Activities
 Running, Dancing, Bicycling, Playing football,
Playing Tennis, Cheerleading, Swimming, Skiing
 You burn 350 or more calories per hour
Determining Your
Calorie Needs for
Physical Activity
Indirect Calorimetrymeasures a persons
oxygen intake and carbon
dioxide output.
THERMIC EFFECT OF
FOOD
10% of your calories are used for this
function
Energy required to complete the processes of
digestion, absorption,and metabolism.
Energy required to extract the energy from
food.
Depends on the types and amount eaten
ENERGY IMBALANCE
Occurs when a person
consumes too few or too
many calories for his or
her energy needs.
ENERGY DEFIENCY
Occurs when energy intake is less than
energy output.
Food sources may be scarce.
Illness may depress appetite
“ Ketone Bodies”- when the body changes
fatty acids into compounds to meet energy
needs.
“Ketosis” –abnormal buildup of ketone bodies
in the bloodstream.
Energy Deficiency
No carbohydrates to burn as energy,
body burns fat (weight loss)
Body changes fat into “Ketone Bodies”
to use as fuel for the nervous system
“Ketosis” is abnormal buildup of ketone
bodies in the bloodstream
Low carbohydrate diets and starvation
will set up a “state of ketosis”.
Atkins Diet an example
Difficult on kidneys and heart
ENERGY EXCESS
Occurs when energy intake
is greater than energy
output.
Body can use stored energy
when there is not enough
food intake to meet
immediate energy needs.
If there is excess energy on
a regular basis- weight gain
occurs
3500 calories = 1 pound of
stored fat
LOCATION OF BODY FAT
Fat stored in the abdomen seems to
pose a greater risk than fat stored in
the buttocks, hips, and thighs.
Fat around the waist increase the liver’s
production of low density lipoproteins,
which is a risk factor for heart disease.
KEY TO WEIGHT MANAGEMENT IS
BALANCING ENERGY IN WITH ENERGY
YOU EXCERT!