Lots More Information

Related HowStuffWorks Articles

• How Calories Work
• How Dieting Works
• How Exercise Works
• How Body Mass Index Works
• How Fat Cells Work
• How Fat Vaccines Will Work

More Great Links

• Surgery reenactment
• Can gastric bypass surgery be redone if you gain the weight back?
• Obesity Action Coalition
• American Society for Bariatric Surgery

Sources 

• Mayo Clinic: Gastric bypass: Is this weight-loss surgery for you? http://www.mayoclinic.com/health/gastric-bypass/HQ01465
• CDC: Overweight and Obesity http://www.cdc.gov/nccdphp/dnpa/obesity/
• WebMD: Gastric Bypass Surgery http://www.webmd.com/diet/gastric-bypass-operations
• WebMD: Weight Loss Surgery Fast Facts ­http://www.webmd.com/a-to-z-guides/weight-loss-surgery-fast-facts
• NIDDK: Gastrointestinal Surgery for Severe Obesity http://www.win.niddk.nih.gov/publications/gastric.htm#normaldigest