Manual of Clinical Nutrition Management III- 72 Copyright © 2013 Compass Group, Inc.
HYPOGLYCEMIA
Discussion
There are two primary categories of hypoglycemia: fasting and postprandial (reactive) hypoglycemia. True
hypoglycemia (nondiabetic origin) is a clinical syndrome with diverse causes in which low levels of plasma
glucose eventually lead to neuroglycopenia (1). Hypoglycemia is defined as the presence of the following
three features, known as Whipple’s triad (1):
a low level of plasma glucose
symptoms of hypoglycemia, such as sweating, shaking, weakness, hunger, headaches, and irritability,
that occur at the same time as the low–blood glucose values
amelioration of the symptoms by the ingestion of carbohydrate
Maintaining blood glucose levels within a normal range is important because the brain and central nervous
system must have a steady supply of glucose to function properly. Symptoms can be recognized when the
blood glucose level is 60 mg/dL, and impaired brain function can occur at a level of approximately 50 mg/dL
(1). When blood glucose levels fall below normal limits within 2 to 5 hours after eating, this condition is
referred to as reactive or postprandial hypoglycemia (1). Postprandial hypoglycemia most frequently occurs
as alimentary hypoglycemia (dumping syndrome) in adults who have undergone gastric surgery, such as a
Billroth gastrectomy. The episode of hypoglycemia usually occurs 1½ to 5 hours after meals, especially
carbohydrate-rich meals. Refer to the “Dumping Syndrome Diet” in Section IB.
Fasting hypoglycemia may occur in response to not eating for 8 hours or longer. Other less common causes
are pancreatic tumors (insulinoma), pancreatic islet cell disease, severe heart failure, and critical organ
failure. Certain medications, such as exogenous insulin, sulfonylureas, ethanol, salicylates, pentamidine, and
quinine, may also cause hypoglycemia in some patients. Diet therapy is the primary treatment, and, in some
cases, adjustments in medications are also needed. Surgery may be required for some conditions, such as
insulinoma. The most frequent cause of fasting hypoglycemia results from the use of insulin or oral glucose-
lowering medications in the treatment of diabetes mellitus. Refer to “Medical Nutrition Therapy for Diabetes
Mellitus” in Section IC.
There are currently no consensus guidelines for the diagnosis of reactive hypoglycemia (1). The diagnostic
techniques range from confirming that the blood glucose level is low during a hypoglycemic reaction after an
ordinary meal to performing an oral glucose tolerance test. However, 10% of asymptomatic healthy persons
respond to the oral glucose tolerance test with a lower-than-normal glucose level.
Nutrition Intervention
The goal of treatment is for the patient to adopt eating habits that will keep blood glucose levels as consistent
as possible (1). These eating habits include consistent meal times and consistent carbohydrate intake (1). As
part of meal planning, determine the frequency and symptoms of hypoglycemia, as well as activity levels and
exercise frequency, and schedule appropriate times for meals and snacks. The treatment of reactive
hypoglycemia depends on the specific cause. The treatment of alimentary hypoglycemia following gastric
surgery is discussed in Section IB: “Dumping Syndrome Diet”). Provided below are guidelines for avoiding
symptoms of hypoglycemia (1):
Allow five or six small meals or feedings per day. Eat consistent amounts of carbohydrate at meals
and snacks from day to day and avoid skipping meals.
Spread carbohydrate intake throughout the day. Most individuals need three to four carbohydrate
servings at meals and one to two carbohydrate servings for snacks (one serving = 15 g
carbohydrate). Include protein foods and vegetables at each meal for satiety and extra energy.
Avoid foods that contain a large amount of carbohydrates, because reactions can occur as a result of
a high carbohydrate load. Examples of these foods are regular soft drinks, syrups, candy, regular
fruited yogurts, cookies, pies, and cakes.
Avoid beverages and foods containing caffeine. Caffeine can cause the same symptoms as
hypoglycemia.
Limit alcohol consumption because it inhibits gluconeogenesis. If an individual chooses to drink
alcohol, it should be limited to one drink per day for women and two drinks per day for men.
Drinking alcohol on an empty stomach and without food can cause hypoglycemia. A carbohydrate
food should always be consumed along with the alcoholic beverage.