inadequate protein intake before and after different types of bariatric surgery: systematic review

Background: bariatric surgery is considered the most effective treatment for morbid obesity. despite the successful weight loss after bariatric surgery, patients are susceptible to protein deficiency. changes in food intake after surgery can cause some nutritional deficiencies. this study aimed to determine the status of protein profile in the patients before and after bariatric surgery. methods and materials: this systematic search was performed in april 2021. cochrane, pubmed, and google scholar databases were used for our literature search by searching the keywords of “body composition”, “fat-free mass”, “bariatric surgery”, “protein malnutrition”, and “protein intake”. results: our studies showed that few studies had evaluated the protein status in candidates before surgery. obesity surgery reduces muscle mass and serum protein, so evaluation of these factors is necessary. the bariatric surgery method exposes people to protein malnutrition and changes in body composition; therefore, more attention to their protein intake needs to be done. conclusion: based on our results, dietary intake can affect the outcome of surgery. so, we recommended evaluating protein status and lean body mass before and after the bariatric surgery. also, the effect of different types of protein supplementation to improve body composition can be assessed in further studies.