Components
of Food
If you
are trying to make heart-healthy changes to your
lifestyle and diet, it is helpful to know some
basics about nutrition, starting with the components
of food.
- You need enough calories
to maintain your energy level, but no more than
you can burn off. This is called an energy balance.
- If you take in more
calories than you burn, you gain weight.
- If you take in fewer
calories than you burn, you lose weight.
- If you balance the
two, you maintain your weight.
- Even when you are dieting,
however, calories should not be cut back so
much that your energy needs are not met. The
number of calories you need depends primarily
on age, gender, and activity level.
- Remember: "cholesterol-free"
does not mean "fat-free."
- Dietary cholesterol
is a fat-like substance found in all foods of
animal origin: egg yolks, meat, poultry, fish,
milk, and milk products.
- Because our bodies
make cholesterol, it is not required in our
diets. However, because most people eat foods
that contain cholesterol, it is important to
avoid excessive amounts. The amount of cholesterol
you consume can affect your blood cholesterol
levels.
Fatty
acids are the basic chemical units in fat. They
may be saturated, polyunsaturated, monounsaturated,
or trans fats. These fatty acids differ in their
chemical compositions and structures, and in the
way in which they affect your blood cholesterol
levels, according to the following:
- saturated fat:
- is used by the
liver to manufacture cholesterol.
- is considered the
most dangerous kind of fat because it has
been shown to raise blood cholesterol levels,
particularly the LDL.
- should comprise
no more than 10 percent of your daily calorie
intake.
- examples include:
meats, butter, cocoa butter, coconut, and
palm oils.
- polyunsaturated fats:
- do not appear to
raise blood cholesterol levels.
- examples include:
safflower, sunflower, corn, and vegetable
oils, margarines, and soybean oils.
- monounsaturated fats:
- do not seem to
have any affect on blood cholesterol.
- examples include
olive and canola oils.
- trans fats: by-products
of hydrogenation, a chemical process used to
change liquid unsaturated fat to a more solid
fat. Structurally similar to saturated fat,
trans fatty acids may have a great impact on
raising total and LDL cholesterol levels.
- examples include
stick margarine and fats found in commercially
prepared cakes, cookies, and snack foods.
Total
fat intake should be no more than 30 percent of
your daily calorie intake.
- All fats contain about
the same number of calories - teaspoon for teaspoon.
There is no low-fat fat.
- Fat is the most concentrated
source of calories, supplying more than twice
as many calories per gram as either carbohydrates
or proteins.
- Most people tend to
get far too much fat in their diets, which contributes
to health problems such as obesity, high blood
cholesterol, and heart disease. While coconut
and palm oils contain no cholesterol, they are
high in saturated fat and should be avoided.
- Fiber is the indigestible
portion of food.
- There are two types
of fiber: soluble and insoluble.
- soluble fiber -
found in such foods as oat bran and dried
beans, can lower blood cholesterol in some
people.
- insoluble fiber
- found in foods such as wheat bran and
is known to have many benefits. While this
type of fiber has not been found to lower
cholesterol, it is useful in weight control
because it creates a feeling of fullness.
- Although salt is the
major contributor of sodium in our diets, sodium
and salt are not the same, contrary to popular
belief. A teaspoon of table salt contains 2,300
milligrams of sodium.
- Sodium is a mineral
needed to maintain body fluids and proper nerve
function. It occurs naturally in some foods,
but most of the sodium in our diets comes from
seasonings and ingredients we add to foods.
- Although sodium is
essential, most of us consume more than we need.
In some people, too much sodium in the diet
can cause the blood pressure to rise, putting
them at risk for heart disease or stroke.
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Resources of Cardiovascular Disease
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