Fasting Blood Glucose
Test
A method for finding out how much glucose (sugar) is in the blood. The
test can show if a person has diabetes. A blood sample is taken in a lab or
doctor's office. The test is usually done in the morning before the person
has eaten. The normal, nondiabetic range for blood glucose is from 70 to 110
mg/dl, depending on the type of blood being tested. If the level is over 140
mg/dl, it usually means the person has diabetes (except for newborns and
some pregnant women).
Fats
One of the three main classes of foods and a source of energy in the
body. Fats help the body use some vitamins and keep the skin healthy. They
also serve as energy stores for the body. In food, there are two types of
fats: saturated and unsaturated.
Saturated fats are solid at room temperature and come chiefly from animal
food products. Some examples are butter, lard, meat fat, solid shortening,
palm oil, and coconut oil. These fats tend to raise the level of cholesterol,
a fat-like substance in the blood.
Unsaturated fats, which include monounsaturated fats and polyunsaturated
fats, are liquid at room temperature and come from plant oils such as olive,
peanut, corn, cottonseed, sunflower, safflower, and soybean. These fats tend
to lower the level of cholesterol in the blood.
Another name for fat is lipid.
See also: Carbohydrate;
protein.
Fatty Acids
A basic unit of fats. When insulin levels are too low or there is not
enough glucose (sugar) to use for energy, the body burns fatty acids for
energy. The body then makes ketone bodies, waste products that cause the
acid level in the blood to become too high. This in turn may lead to ketoacidosis,
a serious problem.
See also: Diabetic
ketoacidosis.
Fiber
A substance found in foods that come from plants. Fiber helps in the
digestive process and is thought to lower cholesterol and help control blood
glucose (sugar). The two types of fiber in food are soluble and insoluble.
Soluble fiber, found in beans, fruits, and oat products, dissolves in water
and is thought to help lower blood fats and blood glucose (sugar). Insoluble
fiber, found in whole-grain products and vegetables, passes directly through
the digestive system, helping to rid the body of waste products.
First Phase Insulin
Release
Release of insulin into the bloodstream from the beta cell
within a few minutes after the blood glucose level rises. It is thought that
this almost immediate release is due to release of insulin that was
previously manufactured, and was being stored in the beta cell.
See also: Second
Phase Insulin Release
Fluorescein Angiography
A method of taking a picture of the flow of blood in the vessels of the
eye by tracing the progress of an injected dye.
Food Exchange
See: Exchange
lists.
Foot Care
Taking special steps to avoid foot problems such as sores, cuts,
bunions, and calluses. Good care includes daily examination of the feet,
toes, and toenails and choosing shoes and socks or stockings that fit well.
People with diabetes have to take special care of their feet because nerve
damage and reduced blood flow sometimes mean they will have less feeling in
their feet than normal. They may not notice cuts and other problems as soon
as they should.
Fractional Urine
Urine that a person collects for a certain period of time during 24
hours; usually from breakfast to lunch, from lunch to supper, from supper to
bedtime, and from bedtime to rising. Also called "block urine."
Fructosamine
A term referring to the linking of blood sugar onto protein molecules in
the bloodstream. The fructosamine value depends upon the average blood sugar
level during the past three weeks. The fructosamine test could be viewed as
complementary to the glycohemoglobin, as the
two tests are different reflections of diabetes control: glycohemoglobin
looks back approximately eight to twelve weeks, and the fructosamine test
looks back about three weeks.
Note: the term fructosamine has nothing to do with the term
fructose.
Fructose
A type of sugar found in
many fruits and vegetables and in honey. Fructose is used to sweeten some
diet foods. It is considered a nutritive sweetener because it has calories.
See also: Glucose, Sugar.
Fundus of the Eye
The back or deep part of the eye, including the retina.
Funduscopy
A test to look at the back area of the eye to see if there is any damage
to the vessels that bring blood to the retina. The doctor uses a device
called an ophthalmoscope to check the eye.