The risks of weight loss surgery compare favorably with other surgeries. In general, the risks of obesity are much greater than the surgery itself. The key decision that needs to be made is the choice between restrictive and malabsorption procedures or a combination of both these two procedures.

It has been noted that though malabsorption procedure of surgery yields better results, it involves greater risks. Restrictive procedures usually lead to a reduction of about 47% of excess weight in patients while the figures for gastric bypass and duodenal switch surgeries (both are malabsorption procedures) are 62% and 70% respectively. On the other hand, whereas the mortality rate for restrictive procedures was 0.1% within the first month of surgery, the mortality rates for gastric bypass and duodenal switch for the 30 days following surgery were 0.5% and 1% respectively. Also, malabsorption procedures have a greater risk of intestine leakage and nutritional deficiencies. Furthermore, gastric bypass operations may cause dumping syndrome (caused when food moves very fast through the small intestine) leading to nausea, weakness, sweating and diarrhea.

Gastric banding was found to be the safest surgical method, although it was less effective, compared to other methods. However, if for any reason, the silicon band used in the procedure was to be removed later, it could be done easily, with the stomach regaining its earlier size in most cases. The lap band method furthermore scored over the staple method in view of the removable band and least amount of surgical work required, as there is no cutting of the stomach in this procedure. A patient must be cautious in deciding which procedure would suit him/her better. It would be wise to discuss the pros and cons extensively with the surgeon before taking a final decision about weight loss surgery.