Download what is nutrition? - Malibu High School

WHAT IS NUTRITION?
Nutrition is the Science of how your
body uses food. Two aspects:
• Energy from food.
• Measured in calories.
• Energy = ability to do
work.
• Nutrients in food.
• Allow the body to
build, maintain and
repair tissues.
• And to do everything
else a body does.
There are also 2 types of Nutrients
• Macronutrients:
protein, fat,
carbohydrates, water
• Micronutrients:
vitamins and minerals
• What do macro and
micro mean?
What is an essential nutrient?
(It is not what it sounds like!)
What does an essential nutrient have to do
with this picture?
An essential nutrient…
• Cannot be manufactured in the body.
• An essential nutrient is linked to a specific
deficiency disease.
• For example, Kwashiorkor is a condition
resulting from inadequate protein intake. A
large, protuberant belly is common.
What is a body made up of?
For a 140 pound (lb)
person:
84 lbs water
28 lbs body fat
Up to 25 lbs protein
Up to 7 lbs minerals
Up to 1.4 lbs.
carbohydrates
Trace amount of
vitamins
So how does it work?
Well, do you remember the digestive
system? What will happen to this mystery food in this
mystery person’s body?
Digestion…it’s a two part process
• Mechanical digestion.
Teeth chewing up
food; stomach
churning food.
• Chemical digestion—
food broken down by
enzymes and other
substances.
Your old buddy…The Small
Intestine
• Nutrients are absorbed here in this order…
1st: Carbohydrates
2nd: Proteins
3rd: Fats
4th: Vitamins
Gross But True Story
William Beaumont, a surgeon in the United
States army was…
Peephole: The first man to
watch a living human gut in
action.
1822, wounded fur trader…
Alexis St. Martin was wounded by a musket
ball that discharged accidentally. It tore
through his back and out his stomach,
leaving a wound that healed but never
closed.
(To keep food and liquid from spilling out of the small opening,
Beaumont kept it convered with a cotton bandage.)
How could this be useful to study nutrition?
Yep, the wound was used to test
how quickly food dissolved.
Ummm…not quite like this
Beaumont’s method: He
tied small pieces of
food (cooked meat,
raw meat, cabbage,
bread) to a silk string
and inserted the food
into the hole in St.
Martin’s stomach.
230 times of “stomach fishing”
later…
He discovered that the carbohydrates
(cabbage and bread) were digested
quickly.
It took up to 8 hours for the stomach juices
to break down the proteins and fats.
What is a calorie?
And how is it like a car?
A Calorie
Like a car that burns gasoline to get the
energy needed to move…
Your body burns (metabolizes) food to
produce energy in the form of heat.
So if a food has 100 calories…
That means it produces 100 calories of heat
that your body can use.
A calorie is the amount of energy it takes to
raise the temperature of water 1 degree
Celcius.
But are all calories equal?
Some foods provide empty calories (no or
little nutritional value).
Other foods provide …
Calories AND Nutrition
For listening to this talk, you
deserve a tasty treat…
Which one will you choose?