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BLOOD CHOLESTEROL:
Cholesterol is a waxy, fat-like substance found in
the bloodstream. It comes from two sources- your body and food. It is made by the liver
and is used by the body to make hormones and other materials. Cholesterol is an essential
part of the human body. It must be present for the body to function normally. However, the
average high-fat/high-cholesterol diet tends to add too much cholesterol to the
bloodstream. The excess cholesterol accumulates, along with other substances, in the walls
of the blood vessels. Over time, this causes the arteries to become narrow and eventually
cuts off the blood flow to the heart leading to a heart attack, or cuts off the blood flow
to the brain leading to a stroke. Blood cholesterol is measured in milligrams per
deciliter (mg/dl). The National Cholesterol Education Program (NCEP) has set guidelines
for classifying blood cholesterol levels. They advise that a total cholesterol level less
than 200mg/dl is a desirable level for adults.
CALORIE:
A calorie is a unit that measures energy.
Calories come from four sources: carbohydrate, fat, protein and alcohol. When nutrition
information is listed on packaged foods, calories are listed for one serving.
The following list shows the caloric value of each
source of energy:
1 gram of protein = 4 calories
1 gram of carbohydrate = 4 calories
(sugar or starch)
1 gram of alcohol = 7 calories
1 gram of fat = 9 calories
The following example shows how to apply the
caloric value of each energy source:.
A serving of cereal may have 16 grams of
carbohydrate, 4 grams of fat, 5 grams of protein and contain 120 calories.
- Carbohydrate
: 16 grams x 4 calories per gram =
64 calories from carbohydrate
- Fat:
4 grams x 9 calories per gram = 36 calories
from fat
- Protein
: 5 grams x 4 calories per gram = 20
calories from protein
1 serving of cereal = 120 calories
DIETARY
CHOLESTEROL:
Cholesterol is found in all animal products: meat, poultry, seafood,
eggs and dairy products. It is especially high in egg yolks and organ meats such as liver,
brains and kidneys. Eating foods high in dietary cholesterol tends to raise the level of
blood cholesterol. The National Cholesterol Education Program (NECP) recommends eating
less than 300 milligrams of dietary cholesterol per day.
Vegetable products do not contain cholesterol, but they may be loaded
with fat. Labels stating "NO CHOLESTEROL" on food packages should alert you to
look at the nutrition information to determine the amount of fat and saturated fat.
Research has shown that saturated fat is the most potent determinant of blood cholesterol
levels (more than dietary cholesterol!)
FAT:
Fat is a major source of calories or energy. Fat improves the taste and odor of foods
and gives a feeling of fullness. Fats form the structures in our bodies, including muscles, nerves, membranes and
blood vessels and are essential for the absorption of fat-soluble vitamins A, D, E and K
in the body.
Although some fat in the diet is necessary, too much fat can lead to heart disease,
obesity and other health problems. There are three kinds of fat: saturated fat,
polyunsaturated fat and monounsaturated fat. Fats in the diet may be of animal (saturated)
or vegetable (unsaturated) origin. Examples of fat in the diet are gravy, bacon,
margarine, butter, cream, salad dressings and nuts. Meats and some milk products also
contain significant amounts of fat. The guidelines recommended by the American Heart
Association and the Surgeon General's Office suggest that fat should contribute no more
than 30% of total calories. For those adults with heart disease a diet of 20 percent or
even 10 percent of calories from fat is advised. The fat we eat is saturated and
unsaturated. These terms refer to the chemical structure of the fat molecules. A low total
fat intake, with the majority of fat from unsaturated sources, appears to lower blood
cholesterol levels. Too much of any of these fats will increase dietary fat intake, and
excess body fat may increase cholesterol levels and the potential to increase body
fat.
FATTY ACIDS:
The major parts of fat. Depending on their chemical structure, fatty acids are
classified as either saturated or unsaturated. Fats found in foods are a mixture of
saturated and unsaturated fatty acids. There are two types of unsaturated fats:
monounsaturated and polyunsaturated.
FIGURING FAT INTAKE:
Regardless of type, all fat has nine calories per gram. Food labeling laws in the U.S.
now require the percentage of fat in a serving of food to be listed (called the
"Percentage of Daily Value" or DV). If the DV isn't listed, divide the number of
grams of fat shown on the label by 65 (which is about the maximum grams of fat recommended
in an average 2,000-calorie-a-day diet).
You can also figure the percentage of fat calories in a serving by the following steps:
- Check label for grams of fat per serving.
- Multiply grams of fat by 9 (1 gram of fat = 9 calories). This equals the calories from
fat.
- Divide calories from fat by the total calories per serving, as listed on the label. The
answer will be a decimal.
- Multiply the answer by 100. This equals the percent of calories from fat.
The American Heart Association Recommends Limiting Fat Intake to 30% of Daily Calories.
Thus, a 2,000-calorie-a-day diet should not contain more than 65 grams or 585 calories of
fat.
If we assume a daily intake of 2000 calories, then no more than 600 calories per day
(30%) should come from fat. Since each gram of fat contributes nine calories, then about
66 grams of fat would be the suggested upper limit of fat intake per day (600 ¸ 9). If you're not careful, it's very easy to go way over that with
just one meal!
So what is a reasonable limit per meal or per entree? If we divide the day's allotment
(66 grams) into three equal meals, then a reasonable limit per meal is 22 grams of fat.
Main entrees usually contribute the largest amount of fat to the meal.
HYDROGENATED
FATS:
Hydrogenated/Partially hydrogenated. Unsaturated
fat that has hydrogen added to make it saturated. Hydrogenation turns liquid vegetable
oils into solid fats. For instance, soybean oil is "hydrogenated" to become a
solid vegetable shortening. Also, hydrogenated vegetable oil may be added to margarine to
make it solid at room temperature and easier to spread. Hydrogenation also helps increase
product shelf life. On the label, the term "hydrogenated" is listed before a
blend of fats and oils. For example: "Hydrogenated vegetable oil (contains the
following: soybean, cottonseed, palm oil)."
LIPIDS:
The general name for fats. Lipids include
triglycerides, phospholipids and sterols. Cholesterol is the best known of the sterols.
The two kinds of lipids in foods that most affect heart disease are dietary fat
(triglycerides, saturated and unsaturated) and dietary cholesterol. About 95 percent of
the lipids in foods and in our bodies are triglycerides.
LIPOPROTEINS:
In the blood, cholesterol attaches to protein
molecules of different densities to be carried through the blood vessels by special types
of proteins, called lipoproteins. The amounts and types of lipoproteins are an important
indicator of your heart disease risk.
Low-density lipoprotein, LDL, is commonly
termed "bad" cholesterol, because an excess of cholesterol carried by them can
lead to the build up of plaque in the arteries. High LDL levels (above 160mg/dl) increase
heart disease risk because they keep cholesterol in blood circulation and carry it to the
arteries to be deposited. Excess body fat and a diet high in saturated fat tend to
increase LDL levels. LDLs are not found in food, only in the body.
High-density cholesterol, HDL, is considered
"good" or protective cholesterol, because they carry cholesterol away from the
arteries to the liver to be excreted from the body. Individuals with high HDL levels
(above 35mg/dl) have a lower risk of heart disease. Regular exercise helps to increase HDL
levels. HDLs are not found in food, only in the body.
MONOUNSATURATED FATS:
Monounsaturated fats typically remain liquid at
extremely low temperatures. These fats are also found in vegetable oils such as olive oil,
peanut oil and canola oil. ) Monounsaturated fat lowers total blood cholesterol by
lowering LDL cholesterol without lowering HDL cholesterol. Research as shown that
substituting monounsaturated fat for saturated fats (and polyunsaturated fats) reduces
blood cholesterol levels without affecting the HDL levels. Too much of any of these fats
will increase dietary fat intake, and excess body fat may increase cholesterol levels and
the potential to increase body fat.
OMEGA-3
FATS:
Some types of fish contain unique polyunsaturated
fats called Omega-3 fatty acids. These fatty acids seem to make blood platelets less
likely to clot, thus decreasing risk of artery blockage and heart attacks. Fish with high
amounts of Omega-3 include salmon, albacore, tuna, mackerel, sardines, herring and rainbow
trout.
POLYUNSATURATED FATS:
Polyunsaturated fats are usually liquid at room
temperature. Polyunsaturated fats are found in vegetable oils such as corn oil, safflower
oil, soybean oil, and sunflower oil. Polyunsaturated fats are also present in fish and
fish oils, which help to decrease triglyceride levels. Polyunsaturated fats lower LDL
cholesterol and total cholesterol but they also lower HDL cholesterol (remember HDL
cholesterol is the good stuff). Therefore, this fat should be limited to a certain degree.
Too much of any of these fats will increase dietary fat intake, and excess body fat may
increase cholesterol levels and the potential to increase body fat.
SATURATED
FATS:
Saturated fats are usually solid or almost solid at
room temperature. All animal fats, such as those in meat, poultry, and dairy products are
saturated. Processed and fast foods are also saturated. Vegetable oils also can be
saturated. Palm, palm kernel and coconut oils are saturated vegetable oils. (Fats
containing mostly unsaturated fat can be made more saturated through a process called
"hydrogenation." See the definition for hydrogenated/partially
hydrogenated.")
Saturated fats are the very unhealthy fats. They
make the body produce more cholesterol, which may raise blood cholesterol levels. Excess
saturated fat is related to an increased risk of cardiovascular disease. The amount of
cholesterol found in foods is not as important as the amount of saturated fat. Of all the
fats, saturated fat is the most potent determinant of blood cholesterol levels. Saturated
fats stimulates the production of LDL cholesterol ("bad" cholesterol) and
therefore increases blood cholesterol levels and the risk of heart disease. Saturated fats
raise cholesterol levels and LDL-cholesterol levels more than dietary cholesterol itself.
TRANS
FATS:
These fats are called hydrogenated fats. These
are fats that are created when oils are "partially hydrogenated" The process of
hydrogenation changes the chemical structure of unsaturated fats by adding hydrogen atoms
to make the fats more saturated. Hydrogenation is what turns liquid oil into stick
margarine or shortening. Manufacturers use this process to increase product stability and
shelf life. Thus, a larger quantity can be produced at one time, saving the manufacturer
money. Unfortunately, this money-saving process is what contributes to elevated blood
cholesterol levels and increases heart disease risk.
TRIGLYCERIDES:
Triglycerides are another type of fat.
Triglycerides are the main form of fat in foods. Triglycerides are produced by the body
and stored as fat from excess calories from any source (protein, carbohydrates, or fat).
Drinking alcohol can also increase levels of triglycerides. Having high triglyceride
levels is not necessarily a risk factor of heart disease but the risk goes up when coupled
with other risk factors.
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