DEAR DR. BLONZ: I would like an explanation of the connection between Type 2 diabetes and obesity. After annual tests, I was told that I was a borderline diabetic. I am only slightly overweight, nothing serious at this point, but I certainly have no interest in going any further down this road. -- F.S., San Francisco
DEAR F.S.: A basic understanding of the relationship between what we eat, our blood sugar level, insulin, diabetes and body weight will serve us well. Digestion involves enzymes acting on foods to break them down into absorbable pieces. In the case of carbohydrates, it means breaking the complex carbohydrate down into its building blocks, which are primarily glucose, as a prelude to absorption. (There is no delay for carbs already in the form of glucose, sucrose or fructose.)
Once absorbed, glucose is often referred to as "blood glucose" or "blood sugar." It serves as a source of energy, but needs to get inside the cells to do its work. To gain entry, glucose requires insulin, a hormone produced and released by the pancreas in response to a rising blood glucose level. Any excess glucose will be changed into fat, the body's most concentrated form of energy, and be put away in storage in the body's fat cells.
Diabetes is present when there's insufficient insulin to get the glucose out of the bloodstream and into the cells. Type 1 diabetes is when the pancreas is unable to produce the insulin. In such cases, replacement insulin needs to be provided, usually by injection.
More common is Type 2 diabetes, which occurs when the pancreas is still able to produce and release insulin, but is unable to keep up with the demand and the blood glucose levels remain elevated. Treatments in such cases can include diet and lifestyle adjustments, or medications to stimulate the pancreas to release more insulin. Type 2 diabetes used to be known as "adult onset" diabetes because it was only seen in adults. With the increasing prevalence of childhood obesity, we now see cases of Type 2 diabetes in children.
The connection with obesity relates to the fact that, as a person gains weight, his or her fat cells increase in size. Scientists have learned that enlarged fat cells are associated with a decreased sensitivity to insulin. This "insulin resistance" means that the body needs more insulin to clear the same amount of glucose out of the bloodstream. The obesity, in essence, overworks the pancreas and eventually it is unable to keep up. Between 80 and 90 percent of those with Type 2 diabetes are obese. This also helps explain why those with Type 2 diabetes often experience dramatic improvements when they lose a few of their excess pounds.
As there can be short- and long-term complications when one's blood glucose remains elevated, the goal with any diabetic condition is to keep the glucose level within normal limits. This can be done with diet, exercise and medication, including insulin. The diet aspect involves the avoidance of eating in a way that brings about a rapid rise in your blood glucose level. Along with this goes regular blood glucose monitoring.
You appear to be at a point where monitoring and lifestyle changes can have a positive impact on your future wellbeing. I encourage you to speak with your family physician and a registered dietitian, who can help you map out strategies for weight control and food selection. It may also help to contact your local chapter of the American Diabetes Association. To find a chapter in your area, check diabetes.org.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.