When we talked about gastric bypass surgery we explained that it doesn't work by keeping you from eating or by keeping you from absorbing the calories you do eat, even tho some misguided people think that's how it works and this kind of surgery is often labeled by terms that sound like that's how it works.
We mentioned that maybe surgery like this mucks up some other hormonal or neural control of appetite and fat storage.
An intriguing report in the New England Journal of Medicine of July 21, 2005 may offer some insight into this question.
Investigators from the Mayo Clinic in Rochester Minnesota found 6 gastric bypass patients who developed nesidioblastosis, an over development of insulin producing cells. The patients had life threatening symptoms of confusion, loss of consciousness and low blood sugar from the over-production of insulin.
Much more commonly gastric bypass can cause dumping syndrome. Dumping syndrome is characterized by flushing, sweating and weakness. It is felt to be caused by too rapid emptying of the stomach contents. So it might have been originally thought that these 6 patients had dumping syndrome, but passing out and very low blood sugar are not part of this syndrome.
Maybe these patients with over-development of the pancreatic beta cells that make insulin had that problem before their gastric bypass surgery and that's what caused them to get so obese. But few patients with insulinomas or nesidioblastosis are as obese as these patients were. Obese people can have elevated insulin but that is because their bodies are resistant to it. Far more commonly they wind up with diabetes or too little insulin production.
On the other hand gastric bypass patients who have diabetes complicating their obesity before the surgery are miraculously cured of it. The resolution of their diabetes occurs very rapidly - too soon to be ascribed to the weight loss, which takes weeks to months.
Herein lies the intriguing part of this story. Somehow other gut hormones that are altered by gastric bypass surgery are signalling the insulin producing cells to grow and make more insulin. In an editorial in the same issue of the New England Journal of Medicine, David Cummings M.D. discusses some of those hormonal alterations.
Maybe those hormones that are being stimulated or suppressed hold the key to less drastic treatment for obesity and type II diabetes. Once more I must admonish you to stay away from the point of view that overeating and poor discipline are the cause and the treatment of obesity if we want to make progress against this epidemic.