Taking the Mystery Out of Calories
What is a calorie? A calorie is a measure of energy, the
capacity to do work. Science defines the calorie as the
amount of energy required to raise the temperature of 1 gram
of water by 1 degree Celsius. In the laboratory, the
calories in a food are determined by measuring the amount in
1,000-calorie units called kilocalories. But in everyday
language this term has been shortened to just "calorie" when
the amount of energy in food is described. Thus, a
165-calorie bagel is really 165 kilocalories.
How many calories do you need? Your body needs energy for
growth, maintenance, and physical activity. The energy
(calorie) intake suggested by the Food and Nutrition Board
of the National Research Council for women 25 to 50 years of
age who are 5 feet 4 inches tall and weigh 138 pounds is
2,200 calories. For men that age who are 5 feet 10 inches
tall and 174 pounds, it's 2,900 calories. These calorie
levels are for women and men of the reference height and
weight engaged in light to moderate activity. The number of
calories you need depends on your height and weight as well
as your age, body size, physical condition, and physical
activity. Younger adults require more calories than older
adults. Active people require more calories than inactive
people. When the food you eat provides more calories than
your body needs, the excess calories are stored as fat and
you gain weight.
Do all calories count? Yes...all calories count, regardless
of the food they come from. But some foods have more
calories than others. Most foods are mixtures of water,
protein, carbohydrates, and fat. The number of calories in a
food depends on how much of each of these is present.
Proteins and carbohydrates have about 4 calories per gram
while fats have about 9. Water has no calories. Alcohol also
provides calories, about 7 per gram.
Is there a secret to losing weight? Whether you have 5
pounds or 20 pounds to lose, the only way you can lose
weight is to consistently eat foods containing fewer
calories than your body needs and uses. This means that you
must either select foods containing fewer calories than you
normally eat or you must increase your activity - preferably
both. An average loss of 1 or 2 pounds a week is about
right. Do not try to lose weight too rapidly.
DIET CAUTIONS
Diet Fads - Be suspicious of diet gimmicks and fad diets
that promise wonders. They can be dangerous. Some are
appealing because they promise quick and easy weight loss,
but unless a diet is balanced nutritionally - as many fad
diets are not - it can be harmful if followed over a period
of time. Diets that encourage little or no eating and diets
that promote heavy eating of one kind of food can cause
health problems. Some people have developed kidney problems,
disturbing psychological changes, and other complications
while following these diets.
Page
1
|
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13
14 |
15 |
16 |
17
| 18 |
19
|
