If you're very overweight and haven’t been able to lose pounds with a healthy diet and exercise, weight loss surgery, also called bariatric surgery, might be an option for you. The requirements for weight loss surgery are usually for those with a body mass index (BMI) above 40 or those with a BMI of 35 or greater with serious co-morbidities. In general, this means men who are more than 100 pounds overweight and women who are more than 80 pounds overweight. (To determine your BMI, you can use the BMI calculator on the National Institutes of Health website.) If you are somewhat less overweight, surgery still might be an option if you suffer from:

• Pulmonary problems
• Diabetes
• Heart disease
• Sleep apnea

How Weight Loss Surgery Works

If you meet the requirements for weight loss surgery, then surgery can promote weight loss by limiting the amount of food your stomach can hold, limiting calorie and nutrient absorption, or both. Some operations also restrict the amount of food you can digest.

• Restriction operations (such as gastric banding and vertical banded gastroplasty)
• Surgeries most often used for producing weight loss
• Restrict food intake by making the stomach smaller and delaying the emptying of food from the stomach, causing the person to feel fuller faster
• Lead to weight loss in almost all patients
• Some weight regain occurs because individuals are unable to adjust their eating habits

Gastric bypass surgeries

• Construct a pathway from the stomach to the small intestine to avoid nutrient and caloric absorption
• Produce more weight loss than restriction operations
• Favored bariatric surgery in the United States because it’s safer and has fewer complications than other weight loss surgeries
• Patients who have bypass operations often lose two-thirds of their excess weight within two years of the surgery.

Weight Loss Timing

Depending on the type of surgery, it is reasonable to expect significant weight loss after surgery. Plus, many of the patients’ obesity-related conditions, such as diabetes or sleep apnea, improve after the surgery. Bariatric surgery also can provide long-term, consistent weight loss when accompanied with a few lifestyle changes.

As with any surgery, there are possible risks with weight loss surgery. A common risk of restrictive operations is vomiting when food is not chewed well and stretches the stomach size. Gastric bypass surgeries may cause “dumping syndrome,” whereby stomach contents move too quickly through the small intestine producing symptoms like nausea, weakness, sweating or diarrhea. There is often the potential for small, treatable complications such as abdominal hernias, gallstones and nutritional deficiencies after weight loss surgery.

Talk with your doctor to find out more about bariatric surgery.