Gastric bypass surgery alters your digestive system in a way that limits your caloric intake. Generally, after the surgery, the amount of food you can comfortably digest changes, creating a limit to how much food you can eat. This is a treatment for obesity that often saves lives and reverses conditions such as Type 2 diabetes. Reduced caloric intake often results in rapid weight loss, which affects metabolism. But gastric bypass surgery can alter your metabolism in other ways too.
Vitamin D Metabolism
Undergoing gastric bypass surgery puts you at risk for a vitamin D deficiency due to post-operative changes in the way your body metabolizes the vitamin. According to a 2006 study published in "Annals of Surgery," gastric bypass patients experience a reduced ability to absorb and properly metabolize vitamin D, leading to increased incidence of vitamin D deficiency. Careful vitamin D supplementation, with long-term vitamin D screening, is necessary to prevent a vitamin D deficiency after undergoing gastric bypass surgery. Your doctor will assess you and make recommendations accordingly.
Gastric bypass patients often experience improved glucose metabolism after surgery. Researchers have not found a definitive reason for this, though studies support several theories. According to a review in the "Internal Medicine Journal," gastrointestinal hormones may play a role. The gastrointestinal hormones glucagon-like peptide 1 and peptide YY are most consistently associated with improved glucose control after gastric bypass surgery, states the paper's author.
Gastric bypass surgery changes the way your body metabolizes alcohol. Gastric bypass patients need to exercise caution when consuming alcohol. According to a study published in the "Journal of the American College of Surgeons," gastric bypass patients are more susceptible to the effects of alcohol, experiencing longer, more intense acute intoxication and needing more time to become sober. The study goes on to say that gastric bypass patients experience higher peak blood alcohol levels than they did before gastric bypass surgery.
How many calories you burn during a state of inactivity is known as your basal metabolic rate. Because gastric bypass surgery alters the amount of food you can comfortably digest, your food intake becomes much smaller than before gastric bypass. According to an article published in "The Journal of Clinical Endocrinology and Metabolism," long-term reduction of caloric intake causes your basal metabolic rate to decline.
- "Annals of Surgery"; The Long-Term Effects of Gastric Bypass on Vitamin D Metabolism; Jason M. Johnson, et al.; May 2006
- "Internal Medicine Journal"; Gastric Bypass and Glucose Metabolism; O. Ukkola; August 2009
- "Journal of the American College of Surgeons"; Impaired Alcohol Metabolism After Gastric Bypass Surgery: A Case-Crossover Trial; G. A. Woodard, et al.; December 2010