Authors: Travis Stork
In healthy people, this entire process takes place without a hitch. You eat, your digestive enzymes break down carbs into glucose, your pancreas releases insulin into your blood, the insulin ushers glucose into your cells, and your cells have the energy they need to do everything they need to do. Case closed.
But this process can hit some major life-threatening road bumps.
Your body’s goal is to keep everything in the food-fuel equation in balance. It does so by constantly monitoring blood sugar and fine-tuning insulin production in response. When blood sugar is high, a healthy body produces more insulin. When it’s low, a healthy body shuts off insulin production. It’s a complex back-and-forth that goes on constantly as your body seeks to keep blood glucose in perfect balance.
In certain people, though, insulin—the bouncer that determines whether glucose gains access to every cell in the body—loses its ability to do its job properly. Instead of perfectly orchestrating glucose’s entry into cells, insulin allows glucose to build up in the blood. And having too much glucose in the blood leads to two problems.
First, when glucose can’t get into the cells, they lose their fuel source and are starved of energy. Without the energy they need, cells struggle to function in a healthy way.
Second, when there’s too much glucose in the blood—a situation referred to as high blood glucose or high blood sugar—all that extra glucose begins to cause damage throughout the body. The liver and muscles try to help out by taking some of the glucose from the blood and storing it away, but they can take only a limited amount. Despite their best effort, there’s still too much glucose floating around in the blood.
Over time, all that extra glucose in the blood starts causing damage throughout the body. It harms blood vessels and nerves. It interferes with the ability of organs such as the kidneys and eyes to function well. It even causes problems in sexual organs.
All this blood sugar trouble results in a disease that I’m sure you’re familiar with because so many Americans have it: diabetes.
So we know that blood sugar can get way too high because insulin starts failing at its job of ushering glucose from the blood to the cells, where it is needed for fuel. The question is: Why does insulin stop working? Why does the cellular bouncer start saying “no” to glucose?
One “big” answer is excess weight—especially excess belly fat around
the waist. Being overweight or obese and having all that extra fat makes it harder for your cells to respond to insulin. Scientists believe the kind of fat that collects deep in the belly (called visceral fat) causes a pro-inflammatory response that makes insulin less effective. In a situation called insulin resistance, cells become increasingly resistant to the action of insulin.
In other words, insulin says, “Let the glucose in,” and your cells say, “Huh?”
Your body responds to insulin resistance by producing even more insulin. Your pancreas, which is located just behind your stomach, starts churning out insulin at a higher and higher rate in an effort to get glucose out of your blood and into your cells. Remember, your body’s goal is to keep blood glucose at an even level—not too much, not too little. Your pancreas starts working overtime to supply the insulin needed to get blood glucose in balance.
For a while, the pancreas can usually keep up with extra-high demand for insulin. But over time, as your body needs more and more insulin, the insulin factories in the pancreas fall behind. This is when type 2 diabetes develops. (Type 1 diabetes is a different kind of disease that is not associated with weight gain but instead occurs when the pancreas stops producing insulin altogether.)
OTHER CAUSES OF INSULIN RESISTANCE
In addition to excess weight, several other things can contribute to insulin resistance:
Inactivity
Cigarette smoking
Sleep problems, such as sleep apnea (more on that in Payoff #5)
Steroid use
Stress
Certain medications, such as diuretics for high blood pressure
Insulin resistance, high blood sugar, and type 2 diabetes don’t develop overnight. Most people have insulin resistance and high blood sugar for many years before their doctors officially diagnose type 2 diabetes. That’s not surprising, since these conditions usually have no noticeable symptoms.
High blood sugar and insulin resistance start slowly, build up gradually, and only become type 2 diabetes when they hit a certain tipping point and you actually develop diabetes.
That build-up time actually has a name—prediabetes. Makes sense, right?
Prediabetes is a condition in which blood glucose is higher than it should be, but not quite high enough to be labeled type 2 diabetes. People with prediabetes are definitely on the road to developing type 2 diabetes. In fact, if they don’t make lifestyle changes like the ones you’re making as part of The Doctor’s Diet, most people with prediabetes eventually get full-blown type 2 diabetes.
Scary and depressing? Sure, especially if you are one of the 79 million American adults who have prediabetes. But hang on for some great news. Prediabetes isn’t a disease; it’s a warning sign—a giant orange warning sign. If you find out you have prediabetes, you still have more than a fighting chance, because prediabetes is amazingly reversible. Simply by losing weight and making some other very doable changes to your lifestyle, you can protect yourself from type 2 diabetes even if you’re already close to developing it.
That’s right: research has shown that by losing weight and increasing physical activity, people with prediabetes can actually prevent or delay the condition from progressing to diabetes.
Here’s how we know the extent to which prediabetes is reversible. More than a decade ago, researchers set out to look for ways to head off type 2 diabetes in people who were on their way to developing it. They launched a major study called the Diabetes Prevention Program (DPP).
Researchers divided more than 3,000 participants in 27 locations around the US into three groups:
Group 1 made changes in their diets and activity levels.
Group 2 made no changes to their diets. Instead, they took twice-daily doses of metformin, a diabetes drug.