"That's loaded with calories!"
"Are you counting your calories?"
When people talk about the calories in food, what do they mean?
A calorie is a unit of measurement - but it doesn't measure
weight or length. A calorie is a unit of energy. When you hear
something contains 100 calories, it's a way of describing how
much energy your body could get from eating or drinking it.
Are Calories Bad for You?
Calories aren't bad for you. Your body needs calories for
energy. But eating too many calories - and not burning enough of
them off through activity - can lead to
weight gain
.
Most foods and drinks contain calories. Some foods, such as
lettuce, contain few calories. (A cup of shredded lettuce has less
than 10 calories.) Other foods, like peanuts, contain a lot of
calories. (A half of a cup of peanuts has 427 calories.)
You can find out how many calories are in a food by looking at
the nutrition facts label. The label also will describe the
components of the food - how many grams of carbohydrate,
protein
, and fat it contains. Here's how many calories are in 1 gram
of each:
- carbohydrate - 4 calories
- protein - 4 calories
- fat - 9 calories
That means if you know how many grams of each one are in a food,
you can calculate the total calories. You would multiply the number
of grams by the number of calories in a gram of that food
component. For example, if a serving of potato chips (about 20
chips) has 10 grams of fat, 90 calories are from fat. That's 10
grams X 9 calories per gram.
Some people watch their calories if they are trying to lose
weight. Most kids don't need to do this, but all kids can
benefit from eating a healthy, balanced diet that includes the
right number of calories - not too many, not too few. But how do
you know how many calories you need?
How Many Calories Do Kids Need?
Kids come in all sizes and each person's body burns energy
(calories) at different rates, so there isn't one perfect
number of calories that a kid should eat. But there is a
recommended range for most school-age kids: 1,600 to 2,500 per
day.
When they reach puberty, girls need more calories, but they tend
to need fewer calories than boys. As boys enter puberty, they will
need as many as 2,500 to 3,000 calories per day. But whether they
are girls or boys, kids who are active and move around a lot will
need more calories than kids who don't.
Most kids don't have to worry about not getting enough
calories because the body - and feelings of hunger - help regulate
how many calories a person eats. But kids with certain medical
problems may need to make sure they eat enough calories. Kids with
cystic fibrosis, for instance, have to eat high-calorie foods
because their bodies have trouble absorbing the nutrients and
energy from food.
Kids who are overweight might have to make sure they don't
eat too many calories. (Only your doctor can say if you are
overweight, so check with him or her if you're concerned. And
never go on a
diet
without talking to your doctor!)
If you eat more calories than your body needs, the leftover
calories are converted to fat. Too much fat can lead to health
problems. Often, kids who are overweight can start by avoiding
high-calorie foods, such as sugary sodas, candy, and fast food, and
by eating a healthy, balanced diet.
Exercising and playing
are really important, too, because activity burns calories.
How the Body Uses Calories
Some people mistakenly believe they have to burn off
all
the calories they eat or they will gain weight. This isn't
true. Your body needs some calories just to operate - to keep your
heart beating and your lungs breathing. As a kid, your body also
needs calories from a variety of foods to grow and develop. And you
burn off some calories without even thinking about it - by walking
your dog or making your bed.
But it
is
a great idea to play and be active for at least 1 hour and up to
several hours a day. That means time spent playing sports, just
running around outside, or riding your bike. It all adds up. Being
active every day keeps your body strong and can help you maintain a
healthy weight.
Watching TV and playing video games doesn't burn many
calories at all, which is why you should try to limit those
activities to 1 to 2 hours per day. A person burns only about 1
calorie per minute while watching TV, about the same as
sleeping!
Reviewed by:
Mary L. Gavin, MD
Date reviewed: March 2007
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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