The Diabetes-Fatigue Connection

Why You're So Tired and What You Can Do About It

by Jack Challem.

Copyright © 2011 by Wiley.

Excerpted with permission of the publisher, Wiley.

One of the most common causes of persistent feelings of physical and mental fatigue is undiagnosed prediabetes or poorly controlled type 2 diabetes. The root of these conditions is primarily dietary — again, too many sugars and sugarlike carbs — and, in most cases, these forms of diabetes can be partially or completely reversed with improved eating habits. It's important for you to understand how blood sugar affects fatigue and energy before I suggest specific dietary improvements.

As I explained in my previous book, Stop Prediabetes Now, sugars and sugarlike carbs are absorbed very quickly, leading to either a steep rise in blood sugar levels or extreme fluctuations between high and low blood sugar levels. How do blood sugar problems contribute to your feeling tired? When blood sugar rises rapidly, such as after you consume a candy bar, an ice cream cone, or a carb-rich meal, your body responds by secreting insulin, a hormone that transports glucose out of the blood-stream and into cells, where the glucose is either stored as fat or burned for energy. In many people, blood sugar and insulin levels oscillate every couple of hours, so that people have alternating periods of low and high energy (rather than steady energy) levels during the day.

The low-energy effect is more noticeable after lunch or dinner, when many people become mentally fuzzy and feel like taking a nap. Several years ago, researchers discovered that high blood sugar levels turn off a brain's production of orexins, a family of chemicals that normally helps keep us alert. Many people incorrectly attribute their tiredness after a meal to low blood sugar (hypoglycemia), and they often respond by eating something sweet, which causes blood sugar levels to spike higher and exacerbate the fatigue.

After a number of years — the time line varies from person to person — the body's cells stop responding to insulin, and both blood sugar and insulin levels remain elevated. At that point, people are insulin resistant and are well on the way to developing type 2 diabetes. At the same time, extreme elevations of blood sugar and insulin prompt the secretion of several inflammation-promoting chemicals called cytokines, particularly interleukin-6 and C-reactive protein, which initiate an "inflammatory cascade" that also contributes to people's feeling tired.

Sugar-related fatigue is one reason why many people have difficulty waking up in the morning. This is especially true of those who routinely eat late-night meals or snack after dinner, such as when they're watching television. Their blood sugar remains elevated overnight, so they feel tired when the alarm clock rings. In addition, they are not hungry in the morning (again, because their blood sugar is elevated), so they skip breakfast. Skipping breakfast further interferes with normal blood sugar levels and sets the stage for their overeating later in the day and feeling tired. Recent research has also shown that eating at the "wrong" times, such as late at night, alters the circadian rhythm and the activity of circadian-dependent genes, all of which can disturb sleep habits, lead to weight gain, and reduce energy levels.

It's not only the steady consumption of bread, pasta, candy bars, and various sweets. Soft drinks also contribute to the blood sugar over-load — a typical 12-ounce can contains approximately 12 teaspoons of sugar, and a 64-ounce bottle has around one-half cup of sugar. The amount of sugar is roughly equivalent to a physician-administered glucose-tolerance test, so one could wryly argue that soft drink companies make a business of dispensing medical tests with a free license. Various fruit juices and yogurt-based beverages can be just as bad as soft drinks, if not worse. Some contain large amounts of so-called natural sugars (for example, glucose and fructose), and others have large amounts of added high-fructose corn syrup.

Frequent and sharp blood sugar swings encourage junk food binges and food addictions. One clue to diagnosing prediabetes and type 2 diabetes is when someone has regular cravings for sugary or carb-rich foods or a penchant for eating sweet foods once or more daily. As blood sugar problems become more serious, the tongue's sensitivity to sweetness tends to decrease, so people will seek out more intense sources of sweetness to get their "sugar hit." Instead of adding one teaspoon of sugar to coffee, they might add two or three teaspoons. Or instead of eating one piece of chocolate, they might have three or four.

Last Modified Date: June 17, 2013

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by Brenda Bell
Years before I was diagnosed with type 2 diabetes, The Other Half came out of a doctor's appointment with a diagnosis of "borderline diabetes" and an ADA exchange diet sheet. His health insurance agency followed up on the diagnosis with a glucometer and test strips. After a year or so of trying to follow the diet plan and test his glucose levels, things appeared to be back in "normal" range, and stood there until a couple of years after my own diagnosis. Shortly...
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