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Alcohol after Gastric Bypass and Sleeve Gastrectomy

By Kathy Scott, RN


Many times both before and after surgery, I have been asked by patients, "what about drinking alcohol?”. The answer to that question is a hesitant "yes but with caution”.


It is a common practice that prior to having bariatric surgery, you first complete a psychological evaluation.  During this evaluation, an investigation into current alcohol behaviors should be identified and explored. A patient who has issues with drugs or alcohol before surgery may still have them after surgery and the tolls that this will have on the body may be greatly amplified postoperatively.  Studies also show bariatric patients may be a risk for transfer addition from food to alcohol.


In a study conducted by Stanford School of Medicine, the effects of alcohol on the postoperative patient were very revealing. A control group of non surgical patients and a group of gastric bypass patients were each given just 5 ounces of wine and were asked to drink this within 15 minutes. Their alcohol levels were then monitored every 5 minutes by breathalyzer until they reached 0. The bypass group not only peaked higher than the control group (.08/.05) but it took 26 minutes longer for them to reach a 0 level. It proved that the gastric bypass patient had alcohol levels that were well above the control group who ingested the same amount. This confirms why I often hear post-op patients say, "I get drunk fast”.


Studies with patients who have had the sleeve gastrectomy also have found higher peaks in blood alcohol concentrations (BAC). In 2020, another study published in Surgery for Obesity Related Diseases also confirmed peaks in BAC that were approximately 50% above the legal driving limit with both the gastric bypass and sleeve.


The other problems with alcohol are health related. Alcohol contains empty calories with no nutritional value which can have a negative impact on your weight loss and nutritional status. In addition, when people drink they tend to relax, let their guard down, abandon their plan and eat too much or the wrong foods. If you are drinking alcohol, you are often not drinking what you should be (water, protein supplements, etc). Alcohol can also contribute to vitamin and mineral deficiencies. We know that alcoholics often suffer from severe vitamin B12 and thiamin deficiencies. Post surgery, patients are often already at risk for thiamin and vitamin B12 deficiencies. Some bariatric patients have issues with enlarged or cirrhosed liver pre-op, and this can be compounded if alcohol is consumed post-operatively. Alcohol, as well as smoking, can also contribute to ulcer formation.


Finally, keep in mind that because alcohol affects you more quickly and is metabolized slower, your motor skills may be impaired differently than before you had surgery. For this reason, driving at all after a drink or two may have disastrous results. Be sure if you do decide to indulge you have a designated driver or plan for getting home.


The lesson in all of this is that alcohol occasionally is acceptable if precautions are taken. It is NOT advisable to do this within at least the first 6 months after surgery (preferably the first 12). After that if you do have the occasional drink to celebrate the New Year, a birthday or anniversary it should be okay. Just be aware of the facts and use them to keep you on track and safe so you can enjoy a healthier new you.


Acevedo MB, Pepino MY, et al.  Alcohol sensitivity in women after undergoing bariatric aurgery: a cross-sectional study. SOARD. 2020 Apr;16(4):536-544.  


Hagedorn JC, Encarnacion B, Brat GA, Morton JM. Does gastric bypass alter alcohol metabolism? SOARD. 2007 Sept; 3(5):543-8.


Chancellor T.L. Facts of Drinking Alcohol After Having Gastric Bypass. Retrieved from eHow 11/11/2010.