Normally when we eat, carbohydrates are absorbed from the stomach and travel in the blood stream to be delivered to the liver and skeletal muscles and deposited therein. This deposition is guided by insulin, to the action of which diabetics are resistant. So in diabetics, carbohydrate calories are absorbed from the stomach and travel in the blood stream for a longer time, failing to be deposited into the liver and skeletal muscle, and thereby raising the blood sugar as measured by fingerstick. Eventually, this blood sugar is delivered to the kidneys, filtered out of the blood and excreted in the urine.
Now on average, 65% of our total daily caloric intake comes from carbohydrates. If these calories end up in the urine, they do not contribute to our total daily caloric intake, which is why out of control diabetics will lose weight. If, for example, we eat 2000 calories a day, absorb 1000 calories into our liver and muscle and excrete 1000 calories in the urine, we are effectively eating only 1000 calories per day and will lose weight.
Successful treatment of diabetes with medication will optimize the absorption of blood sugar into the liver and skeletal muscle, evacuating that sugar from the blood and lowering our fingerstick readings. However, this also increases our effective daily caloric intake, which might then contribute to weight gain.
This is why we can't just treat diabetes with medication alone; diabetics treated thusly will eventually gain weight, which will increase their resistance to insulin and thereby worsen their diabetes. In response, more medication will be prescribed and the paradox deepens and treatment becomes self-defeating.
A healthful calorie restricted diet along with a regular cardiovascular exercise program will help defeat the diabetic dilemma. Regular exercise will train the body to use more ingested calories for energy so less are deposited into the body. And resultant weight loss will reduce the body's resistance to insulin, which would allow for the treatment of diabetes with less medication.