Unexpectedly High Blood Sugars and the All-You-Can-Eat Effect

Part of the peculiar biology of diabetes is a reaction called sometimes called the buffet effect, or the all-you-can-eat effect. Even the healthiest salad or a low-carb, high-soy Asian meal can cause drastic increases in blood sugars.

This is due to the fact that the small intestine contains receptor cells that release hormones into the bloodstream when they are stretch. The small intestine signals the pancreas that sugar is on its way and the body will need insulin to keep blood glucose levels from going too high. The larger the meal, the greater the stretching of the intestinal fibers, and the greater the amount of insulin the pancreas is required to produce.

Just to make sure that blood sugars don’t go too low, the pancreas also releases a hormone called glucagon that tells the liver to release some of its stored glycogen as glucose. This effect is caused solely by the bulk of the food consumed. Whether you eat a huge bowl of salad, a 24-oz steak, or a whole apple pie, the pancreas gets the same message to release insulin, plus some glucagon just in case the small intestine was sending a false alarm.

The trigger for this pancreatic response works the same way in diabetics and non-diabetics. Even if you just eat strictly low-carb foods, if you eat a lot of them, your pancreas gets the same message as if you ate a large meal of high-glycemic carbohydrate. The problem is, in diabetics, the pancreas gets the signal to release insulin and glucagon and can only release glucagon. A bowl of sawdust, if you could get it down, could cause a sharp rise in your blood sugars. A bowl of salad also does.

Even worse, the diabetic pancreas lacks the ability to secrete another hormone produced in this process, amylin. Amylin reduces the blood-sugar increases caused by glucagon, and works on the brain to signal that you have eaten enough. Your body is releasing sugar even when you have eaten a low-carb meal, and your brain is telling you to eat more!

The moral of this lesson is: Don’t stuff yourself! And equally important: There’s no such thing as a free food! Any solid food that your overeat can raise your blood sugars.