If you’ve read this far and are thinking, “I’m in good shape; this article doesn’t apply to me,” think again. About 20% of those with prediabetes are at what would be considered a healthy weight or body composition. In fact, this condition may precede weight gain often associated with diabetic and prediabetic conditions. As you’ll see below, prediabetes may be a sign of other unwanted health effects as well.
Blood Sugar 101
To maintain optimal health, glucose must be maintained within a relatively close range in the blood. Blood sugar rises typically come from two sources — from the carbohydrates (and under special circumstances, protein) in one’s diet and from glycogen stored in the liver. Carbohydrate-rich food has the ability to significantly increase blood sugar levels. As glucose enters the bloodstream, the body must use it for immediate energy or store it in order to bring blood sugar levels back down.
Glucose can be stored in the muscle and liver as glycogen, but only a very small amount can be stored there. Even seasoned athletes are only able to store about 500 grams of glucose as glycogen. In an average day, including an intense one-hour workout, the average person uses only a fraction of their available stored glycogen on a daily basis, much of which can be replaced by the body without the need for a lot of dietary carbohydrates. Many people think they need a lot more carbohydrates than they really do. When they eat too many on a regular basis, it can result in a dysfunctional metabolism.
Think of it this way. Let’s say your car’s gas tank holds 15 gallons of gas. You fill up Saturday morning and drive all over town getting your weekend shopping done. You think to yourself, “Wow! I did a lot of driving today! I better fill up the tank again.” You drive back to the gas station and force 8 gallons of gas into the tank. Your perception is that you’ve done a lot of driving and probably used a lot of gas. In reality, you only used 2 gallons. Your gas tank overflows and six gallons of gas spill out of the tank and all over the ground. You have no place to store the extra gasoline, so in this case, you make a mess on the pavement (and a fire hazard) and the extra gasoline is just wasted.
Your body, on the other hand, rarely wastes anything. Using the same analogy, let’s say you have a really active day. In your mind, you’ve been on your feet most of the day running errands. You squeezed in a great workout in your favorite group fitness class, and when you get home in the evening you think you need (or deserve) a carbohydrate-rich meal. You may have even grabbed a bagel or muffin following your group fitness class because you thought you had earned it. Throughout the day, your body burned a mix of carbohydrates and fat. At the end of the day, you might have burned a total of 200 grams worth of carbohydrates, but you eat the USDA’s recommended 300 grams of carbohydrates. What do you do with the extra?
Your body can’t waste the extra glucose you consume. Instead, once your glycogen stores are filled up and your energy needs are met, the remaining glucose is stored as fat. The fat can show up in your blood as elevated triglycerides or in your fat stores as body fat. This fat is only released from the fat cells for energy when the body isn’t depending on carbohydrates for fuel.
Elevated Glucose Levels
For healthy individuals, the body maintains blood glucose levels within a narrow range, low enough to avoid health problems. As dietary carbohydrate enters the digestive system, and eventually the blood stream, insulin is released to help open the muscle and fat cells for the incoming calories. The more healthy, or sensitive an individual is, the less insulin he or she needs to move the glucose into muscles, liver cells, or move extra fat into the fat cells.
After years of eating a high-carbohydrate diet, those cells may lose their sensitivity to insulin. To get blood sugar levels down, the body must secrete even more insulin, which shuts down fat burning and may increase inflammation levels. Since the body isn’t as effective at moving glucose out of the blood stream, levels in the blood get higher.
This is why fasting glucose levels are such a great way to see whether there is a disruption in the body’s ability to manage blood sugar. Elevated blood sugar is a sign the body can’t handle incoming carbohydrate very well.
Diabetes is often diagnosed when fasting blood sugar is greater than 125 mg/dL. Fasting blood glucose levels of 100–125 mg/dL are a sign of insulin resistance or prediabetes. Unfortunately, many people who visit their doctor with blood sugar levels within this range are given little to no instruction. We’ve heard from many people who were told “There’s nothing I can do for you today. Your blood sugar levels aren’t high enough yet. Come back when they’re over 125 mg/dL and I’ll be able to prescribe something for you.”
There’s actually much that can be done to reverse this trend in an individual without needing to resort to drug therapy. The recommendation to wait until a certain blood sugar level is met is the equivalent of telling someone not to worry about smoking until they actually have lung cancer. On the other hand, many of the effects of poor blood sugar control can be drastically reduced in a short period of time with dietary and lifestyle choices.
Even the 100 mg/dL cutoff range for prediabetes may be too high. A large study by Kaiser Permanente suggested that each point above 84 mg/dL for fasting blood glucose meant a person had a 6% increased risk of developing diabetes.
Rather than thinking of blood sugar levels as “good, kind of bad or really bad” based on clear-cut numbers, think of it as a spectrum. If 84 or less seems to be ideal, 88 mg/dL isn’t that far off and is still pretty healthy. A blood sugar measure of 95 mg/dL isn’t at a “prediabetic” level yet, but it’s getting close and should raise some red flags. The key is having your blood sugar level measured regularly.
A fasting blood sugar level of 95 mg/dL could be outstanding if one’s previous level was 110 mg/dL a few months earlier, because it’s trending down. But it’s not a very good level if the previous measure was 86 mg/dL because it’s trending up. That’s why you should have your levels checked on a regular basis.
Dangers of Elevated Blood Sugar
Other than elevated triglycerides, which increase heart disease risk and a greater likelihood of storing unwanted body fat, what else can elevated blood sugar do to the body?
First, elevated blood sugar can increase the body’s rate of aging by developing AGEs, or advanced glycation end products. Without going into great detail, the sugar in the blood can cause amino acids, fatty acids or DNA to stick together and disrupt their ability to function properly. It sounds pretty serious, doesn’t it? It is!
AGEs are thought to cause blood vessel damage, atherosclerosis, Alzheimer’s disease, renal disease, rheumatoid arthritis, muscle loss, bone loss, cataracts, Parkinson’s disease, vascular dementia and additional degenerative diseases.[i]
AGEs may also increase rates of oxidation. The best physical example of oxidation is when metal rusts. A certain amount of oxidation is natural, and an antioxidant-rich diet and exercise can help the body handle normal amounts of oxidation. However, AGEs may speed up the rate of oxidation in the body which could increase the risk of developing cancer.
If you think elevated blood sugar levels sound pretty scary, they are. The next question then is, what can be done to reduce blood sugar levels?
The most obvious choice you can make to reduce blood glucose levels is to stop loading your bloodstream with excessive carbohydrates. Organic, gluten-free cookies; sugar in low-fat yogurt; candy; pasta; beer; cereal; potatoes. They all end up in the bloodstream as glucose. Some of those options are better than others, but they still end up in the bloodstream as glucose. Depending on how elevated one’s blood sugar levels are, reducing or eliminating many of those carbohydrate-rich foods may be appropriate.
One carbohydrate source plays a unique role in how blood sugar is managed — fructose. Fructose, often called “fruit sugar,” is metabolized differently than other carbohydrates. Fructose is able to easily enter the bloodstream where it is immediately shuttled to the liver rather than being accepted by muscle or used for energy. The liver converts what it can and turns the rest into triglycerides. Consuming too much fructose can contribute to insulin resistance like other sugars, but it is likely a major contributor to non-alcoholic fatty liver disease, common in those with diabetes. “All-natural” sugars like honey and agave nectar as well as fruit juice, sucrose and high-fructose corn syrup are common dietary sources of fructose.
There is also some indication that vegetable oils may disrupt the body’s ability to manage blood sugar. Interestingly, vegetable oils are also found along with sugars in processed foods. Eliminating processed foods in the diet, even if they’re called “organic,” can play an important role in managing blood sugar.
Exercise improves insulin sensitivity, which means when there is extra glucose in the blood, it’s easier to move it from the blood into the muscle cells. In addition, regular exercise helps the body to store more glucose as glycogen, so as it is consumed there’s more space for it to go somewhere other than fat cells or the development of blood triglycerides.
As good as exercise can be for people, it is possible to negatively impact the body’s ability to control blood sugar. High-intensity exercise relies on a large amount of glycogen for fuel. A poorly designed exercise program can train the body to rely predominantly on sugar for fuel and become inefficient at burning fat.
Another common mistake exercisers make is not allowing the body sufficient recovery time between intense workouts. Overtraining is the result of physical and mental stresses exceeding the body’s ability to recover. Even a combination of a moderate amount of high-intensity exercise added to a consistently stressful career can result in overtraining.
Every body is different and will hit its recovery limit differently than others. Individuals get more benefit from allowing too much recovery time than not enough. That said, a properly scheduled exercise program can provide tremendous benefit to blood sugar management.
Stress & Sleep
Stress plays a role in blood sugar levels as well. Under stress, the body secretes the well-known hormone cortisol. Part of cortisol’s role is to release glycogen into the bloodstream as glucose. Thousands of years ago this made sense, as the secretion of glucose into the blood would allow for easy energy sources to fuel the “fight or flight” response. Today when we feel stress at work or in life, it isn’t followed by immediate, intense exercise. Instead, the blood sugar isn’t needed and can result in elevated blood sugar levels over time. Controlling stress levels can help in reducing blood sugar levels.
Stress affects the ability to sleep as well. A single night of insufficient sleep can make the body insulin resistant and create a craving for carbohydrate-rich foods. If you’re getting less than 6 hours of sleep each night and think you can handle it, think again. Research says you need sleep for a healthy metabolism.
You can’t judge a book by its cover. You need to read what’s inside the book. You also can’t judge your health by looking in the mirror. You need to regularly check in on what’s happening inside. If you’re healthy, get your blood sugar levels (and other metabolic markers) checked a couple times per year to make sure you stay that way. If you have any signs of a disrupted metabolism, or if you’re approaching the danger zone of fasted blood sugar (100 mg/dL), do something now. With the right lifestyle and nutrition choices, you can turn things around quickly. If you put it off, there are a variety of other complications that may follow your failing control of blood sugar.
Written by Tom Nikkola - Director of Nutrition & Weight Management
This article is not intended for the treatment or prevention of disease, nor as a substitute for medical treatment, nor as an alternative to medical advice. Use of recommendations in this and other articles is at the choice and risk of the reader.