Type 1
Five to 10 percent of people with diabetes fall into this category, which used to be called "juvenile diabetes" because it is most often diagnosed before age 30. However, type 1 diabetes can occur at any age, even in the elderly. People with type 1 diabetes are unable to produce their own insulin, so they must take insulin daily in order to survive. Given in injections or through a pump, the insulin doses are timed to correspond with food intake, so an eating plan is an essential part of treatment.
Type 2
Type 2 diabetes—by far the most common kind, accounting for nine out of ten American cases—is caused by a combination of problems. It usually begins as body cells become insulin resistant—less able to process insulin's signals. But as long as the body can make enough insulin to overcome the resistance, blood-glucose levels remain normal. Eventually, however, the pancreas can't produce enough insulin to overcome this resistance, and the problem becomes a deficiency in insulin. Even though insulin levels may still be higher than normal, the amount just isn't enough to keep blood-glucose levels within a normal range. The longer a person has diabetes, the more likely it is that insufficient insulin is the cause of high blood-glucose levels.
When type 2 diabetes is first diagnosed, many people can control their glucose by making and maintaining changes in their eating and physical activity. But diabetes is a progressive disease; over time, lifestyle changes need to be combined with medications, such as diabetes pills—and, eventually for many, insulin. When some people with diabetes reach this point, they may blame themselves, or feel as if they've "failed." In fact, diabetes progression isn't anyone's fault, but rather the result of inheriting beta cells that fail over time. To keep the beta cells working longer, it's important to keep blood-glucose levels as normal as possible by whatever means necessary.
Gestational Diabetes
This form of diabetes affects about 7 percent of all pregnant women in the U.S. It usually develops during the last part of a pregnancy, when hormonal changes can increase the body's demand for insulin. It is generally treated with an eating plan and careful blood-glucose monitoring, to make sure both mother and infant are getting the nutrients they need. Most cases resolve once the baby is born, but women who have had gestational diabetes are at an increased risk of developing type 2 diabetes. Close to 40 percent of women who have had gestational diabetes eventually develop type 2 diabetes.
Prediabetes
Before people develop type 2 diabetes, they often have higher-than-normal blood-glucose levels, but not high enough for a diagnosis of diabetes. An estimated 41 million people fit this "prediabetes" category. They have attracted lots of attention from diabetes researchers, and not just because of their numbers. Studies show that people with prediabetes can cut their risk of progressing to full-blown diabetes by at least half. How? By making small lifestyle changes, such as exercising regularly and losing just 5 to 10 percent of their body weight (for a 150-pound person, that's 7 1/2 to 15 pounds). In one study, such changes were more powerful in lowering diabetes risk than a widely used diabetes drug!
