What if I lose too much weight after surgery?

What if I lose too much weight?

Many of my patients who have had weight loss (i.e. bariatric) surgery like the sleeve gastrectomy or gastric bypass operation (i.e. stomach stapling) will ask me, “what will happen if I lose too much weight?” Honestly, this is a very rare occurrence. In my ten years of experience as a bariatric surgeon, I have only seen two patients lose too much weight. On patient became bulimic and recovered after reversing the operation, and the other patient had another medical problem unrelated to her surgery (she did not need a reversal or revision of her weight loss surgery).

The reason patient’s do not lose too much weight after surgery is that the body has a natural “protection” weight. That is, there is a weight that the body will get down to that seems “normal” and then it will defend that weight. While the patient is over that weight, the body feels that it is in an overfed state, and hunger is an uncommon experience. However, once the person goes below that weight, the body feels under fed. In the under fed state, that body returns the sensation of hunger and appetite, and ensures that the person now eats enough calories to maintain the new, healthier weight.

Surgery to lose weight is safer today than it has ever been. Our long experience with operations like the bypass surgery and the newer sleeve gastrectomy gives us a good appreciation for the normal expected weight loss after the operation. On average, patients who are 100 pounds over their ideal weight will lose between 60-80 pounds with the bypass and 50-70 pounds with the sleeve. These averages have a wide range and deviation from one patient to the next depending on how well they do with diet and exercise program, and there is generally a 20% fluctuation in the weight after 5 years. Nonetheless, the upper limit of weight loss is fairly limited and malnutrition rare with appropriate vitamin and mineral replacements.