Hypoglycemia develops when the glucose (sugar) level in your blood falls below normal. During the process of digestion, the carbohydrates (sugars and starches) that you eat every day are converted into glucose. Glucose is often referred to as blood sugar because it is absorbed by your blood stream and carried to every cell in your body. Unused glucose is stored in your muscles and liver as glycogen. Your body draws on its sugar stores for energy when your blood sugar drops.
Whenever you eat food, the breakdown of carbohydrates into glucose causes your blood sugar level to rise. This triggers your pancreas, an organ located in your upper abdomen, to release a hormone called insulin. Insulin helps glucose enter body cells, where it supplies the energy to fuel most bodily functions. As glucose is absorbed into the cells, your blood sugar level gradually drops back to a normal range.
A few hours later, when most of the available glucose supply is consumed, your blood sugar levels start to fall below normal, indicating that your body needs more fuel. Your pancreas responds to the falling glucose levels by releasing a different hormone, called glucagon. Glucagon stimulates your liver to release its stored supply of glucose into the bloodstream, where it is circulated to the cells. Once again, your blood sugar levels rise back to normal. By relying on insulin, glucagon and several other hormones, your body is able to keep your blood glucose levels under constant control and regulate your daily energy supply.
Hypoglycemia occurs when your blood glucose levels drop too low and you no longer have enough energy to fuel your daily activities. Hypoglycemia develops most often as a complication of diabetes. Many people with diabetes have to take insulin or other drugs to keep their blood sugar level in the normal range. When people with diabetes eat too little food, exercise too strenuously, drink too much alcohol, or take too much medication, they are at risk of developing hypoglycemia.
Hypoglycemia can also occur in people who don't have diabetes. If you develop low blood sugar symptoms after eating a meal, you may have reactive hypoglycemia. This type of low blood sugar reaction occurs when the pancreas releases too much insulin at once, causing your blood sugar level to fall below normal. Symptoms usually develop within two to five hours after eating a meal.
If you are prone to reactive hypoglycemia, eating too many starchy or sweet foods can aggravate the condition. That's because large portions of carbohydrate-rich foods cause your blood sugar to rise very rapidly, triggering excessive insulin production and a dramatic drop in your glucose level, leaving you feeling sweaty, anxious, hungry and shaky.
Other possible causes of hypoglycemia include:
- Stress and anxiety
- Chronically following an unbalanced diet that is high in refined grains and/or sugars
- Drinking alcohol
- Early pregnancy
- Prolonged fasting
- Long periods of strenuous exercise
- Exercising while you are on beta blocker medication (e.g. propranolol)
- Liver disease
- Gastric surgery that disrupts the balance between digestion and insulin release
- Hereditary intolerance of foods that contain the natural sugars fructose and galactose (rare childhood conditions).
When your blood sugar level falls, your body responds by releasing a hormone called epinephrine (adrenaline) from your adrenal glands. This hormone stimulates your liver to release its stored glucose into your bloodstream. But this adrenaline rush also produces the symptoms that are characteristic of hypoglycemia such as sweating, nervousness, rapid heartbeat, hunger, faintness and trembling.
If your blood sugar level continues to fall, the reduced glucose supply will begin to affect your brain. Symptoms include headache, dizziness, confusion, blurred vision, difficulty concentrating, anxiety, agitation, and abnormal behaviour that could be mistaken for drunkenness. If your condition continues to worsen, convulsions, loss of consciousness and coma may result. Such life threatening symptoms are usually caused by too much medication in people with diabetes.
Who’s at risk?
If you have symptoms of hypoglycemia and you do not have diabetes, your doctor may conduct some simple blood tests to measure your blood sugar and insulin levels. Ideally, this test will be done while you are experiencing an episode of hypoglycemic symptoms. The diagnosis of hypoglycemia will be confirmed if the blood test indicates that your blood sugar levels are below normal and your symptoms improve when you consume sugar.
For years doctors used the oral glucose tolerance test to diagnose hypoglycemia. However its use has fallen out of favour because it can produce misleading results. It is now recognized that the signs and symptoms of hypoglycemia can occur in individuals who have blood glucose levels within the normal range. Relying on a blood sugar test alone is often not enough to diagnose hypoglycemia.
One of the most useful ways to determine if you suffer from hypoglycemia is to assess your symptoms. In general, when symptoms appear three to four hours after eating and disappear after you've consumed food, hypoglycemia is a likely cause.
Nutrition tips to prevent hypoglycemia
The section below focuses on nutritional strategies that will help maintain a consistent blood sugar level so you are less vulnerable to experiencing hypoglycemia. Over the years, I have had many clients seek my help for managing their hypoglycemia. They have learned that following the proper diet is key to preventing hypoglycemia. Instead of relying on fast acting carbohydrate to treat a low blood sugar reaction, use the strategies below to prevent a sugar low from occurring in the first place.
Eat at regular intervals. One of the first and most important ways to prevent a low blood sugar reaction is to eat regularly throughout the day. After eating a meal, your blood sugar will peak 45 to 90 minutes later. After this point, your sugar level starts its decline. If you suffer from hypoglycemia, you should eat every three hours. That means eating three meals and three snacks. Here's what a meal and snack schedule might look like if you work during the day (e.g. 9:00 a.m. to 5:00 p.m.):
- Breakfast: 7:30-8:00 a.m.
- Snack: 10:00 -10:30 a.m.
- Lunch: 12:00 - 1:00 p.m.
- Snack: 3:00 - 4:00 p.m.
- Dinner: 6:00 - 7:00 p.m.
- Snack: 8:00 - 9:00 p.m.
Once you get into a consistent pattern of eating you will feel so much better. And if you choose the right foods at your meals and snacks, chances are you'll forget that you are vulnerable to hypoglycemic reactions.
Choose the right carbohydrates (low glycemic index). Carbohydrate-containing foods such as starches, fruits, milk, and sugars eventually wind up as glucose in the bloodstream. But not all carbohydrates behave the same way when it comes to raising your blood sugar. Some carbohydrate-rich foods are digested and absorbed into the blood stream quickly while others are broken down and converted to glucose slowly.
Foods that are converted to blood glucose quickly (e.g. white bread) trigger your pancreas to release an excessive amount of insulin, causing your blood glucose level to drop to a very low level. On the other hand, foods such as high fibre breakfast cereals or yogurt are digested and absorbed more slowly, causing a gradual rise in blood sugar. This does not cause the pancreas to release such as large amount of insulin. As a result, your blood sugar level won't plummet. Instead you will experience a smooth, steady blood sugar level leading to more consistent energy levels.
The rate at which a food causes your blood sugar to rise can be a measured and assigned a value. This measure is referred to the food's the glycemic index value. The glycemic index (GI) is a ranking from 0 to 100. The number tells you whether a food raises your blood glucose rapidly, moderately, or slowly. Foods that are digested quickly and cause you blood sugar to rise rapidly have high glycemic index values. Foods that are digested slowly leading to a gradual rise in blood sugar are assigned low glycemic index vales. All foods are compared to pure glucose, which is given a value of 100 (fast acting).
To choose carbohydrate foods that do not cause large increases in blood sugar.
Choose low GI foods at your meals and snacks. Avoid eating high GI foods as snacks as they can trigger a low blood sugar. Combining a high GI food with a low GI food will result in a meal with a medium GI value. A list of foods ranked by their GI value can be found in Chapter 1 Carbohydrates.
Boost your soluble fibre. Many of the foods with a low glycemic index value tend to be higher in a special kind of fibre, called soluble fibre. Dried peas, beans, and lentils, oats, barley, psyllium husks, apples and citrus fruits are all good sources of soluble fibre and as you will see from the GI table on page x these foods also have a low GI. When you eat these foods, the soluble fibre forms a gel in your stomach and slows the rate of digestion and absorption. That means your blood sugar will rise at a slower rate and your pancreas won't produce excessive amounts of insulin.
If you don't feel like using the GI table to choose foods, you might just plan your meals around foods rich in soluble fibre:
- Cereals -- Kellogg's All Bran Buds with Psyllium, Oatmeal, Oat Bran
- Grains -- Barley
- Legumes -- All (baked beans, bean soups, black beans, chickpeas, kidney beans, lentils, soybeans, etc.)
- Fruit -- Apples, Cantaloupe, Grapefruit, Oranges, Pears, Strawberries
- Vegetables -- Carrots, green peas, sweet potato
Get enough protein. Adding a little protein to meals slows the rate at which your stomach empties its contents into the small intestine. As a result, the carbohydrate in your meal will enter your bloodstream at a slower rate. Choose lean protein foods such as lean beef, chicken breast, turkey, pork tenderloin, center cut pork chops, fish, seafood and eggs. If you are a vegetarian include vegetarian protein foods at your meals - tofu, beans, veggie ground round, and tempeh. Dairy products such as milk, yogurt and cheese also contribute protein to a meal.
To help manage your blood sugar, distribute your protein throughout your day. If you need to eat 60 grams of protein each day, aim for 20 grams at each meal.
If you enjoy a green salad with your meal, continue doing so. Just make sure you toss it with a vinaigrette dressing. Studies have found that vinegars, especially red wine vinegar, also slow the rate at which food leaves your stomach.
Avoid caffeine and alcohol. Caffeine is known to cause a low blood sugar reaction, especially if it has awhile since you last ate. Researchers from the Yale University School of Medicine found that consuming 400 milligrams of caffeine triggered hypoglycemia when blood sugar levels were in the 'low-normal' range, as might occur two to three hours after a meal.
If you are sensitive to caffeine, switch to low caffeine or caffeine free beverages. Replace coffee with decaf coffee, cereal based beverages (e.g. Ovaltine), herbal tea, weakly brewed black tea, or green teas. If you don't want to part with your daily cup of coffee, drink it with a meal so caffeine will be less likely to trigger a low blood sugar reaction. Between meals, stick to vegetable juice, water, milk, herbal tea, or decaf lattes.
Drinking alcoholic beverages can also impair blood sugar control and trigger a hypoglycemic reaction in susceptible individuals. It can induce reactive hypoglycemia by interfering with glucose uptake and promoting the release of insulin from your pancreas. The drop in blood sugar that follows leads to a craving for foods, especially sweets. If you reach for sugary foods in response to this low blood sugar, you'll only aggravate your symptoms.
If you have hypoglycemia, avoid drinking alcohol on an empty stomach. Instead, enjoy your drink with a meal. The presence of food in your stomach will delay the absorption of alcohol. If you do drink, limit yourself to seven alcoholic drinks per week for health protection.
Vitamins and Minerals
Consider more chromium. Supplements of this trace mineral have been promoted to manage hypoglycemia, but unfortunately research studies are far and few between. One small study was conducted in the late 1980's with eight women who had hypoglycemia. Those who took 200 micrograms of chromium for three months experienced a significantly fewer low blood sugar symptoms and had higher blood glucose levels two to four hours after eating. Another small study conducted among 20 patients with hypoglycemia found similar results using 125 micrograms of the mineral. A larger number of studies have investigated the use of chromium in individuals with type 2 diabetes.
It appears that chromium does play an important role when it comes to regulating blood glucose. Chromium is used by the body to make 'glucose tolerance factor (GTF)', a compound that interacts with insulin and helps maintain normal blood sugar levels. With adequate amounts of chromium present, your body uses less insulin to do its job.
The recommended intake for chromium is 55 micrograms per day for women and men. Chromium-rich foods include apples with the skin, green peas, chicken breast, refried beans, mushrooms, oysters, wheat germ and Brewer's yeast. Processed foods and refined (white) starchy foods like white bread, instant rice and white pasta, sugar and sweets contain very little chromium.
If you're concerned you're not getting enough through food, check your multivitamin and mineral to see how much it contains. If it's less than 50 micrograms, consider taking a separate 100 or 200-microgram supplement each day.
Other lifestyle factors
Get regular exercise. Exercise improves many aspects of blood sugar control. Working out enhances the body's sensitivity to insulin, improves glucose uptake by your cells, and also increases the concentration of chromium in your tissues.
You don't need to exercise vigorously to reap the benefits. In fact, working out too intensely may bring on hypoglycemia. If you exercise with someone, you should be able to carry on a conversation (you should be a little breathless though). If you workout at a gym, consult with a certified personal trainer to help you find your target heart rate zone. Staying within this range while you exercise will prevent you from overdoing it. Good activities include brisk walking, jogging, stair climbing, swimming, rowing, and cycling. Aim to exercise four times per week, each session at least 30 minutes long. If you are not there right now, gradually work up to this.
Plan your snacks around your exercise session. If you eat lunch at 12 noon and exercise at 3:00 p.m., you'll want a snack about 30 minutes before you begin. At 2:30 p.m. try a banana, a yogurt or a sports energy bar. Depending on what time you eat dinner, you'll likely need to eat another small snack around 4:00 or 4:30 p.m.
National Diabetes Information Clearinghouse (NDIC)
Mayo Foundation for Medical Education and Research
The Hypoglycemia Support Foundation Inc.
The above is an excerpt from "Leslie Beck's Nutrition Encyclopedia" (Penguin Canada, 2001/2003), available at bookstores across the country. The following is copyrighted and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or means - electronic, mechanical, photocopying, or likewise.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.