In the United States, there are four main weight loss surgery procedures performed: gastric bypass, duodenal switch, sleeve gastrectomy, and lap-band. Regardless of the procedure, patients must follow strict diet protocols when preparing for surgery, as well as after surgery to allow healing.
Once patients are cleared to consume a normal diet, the guidelines become more flexible. However, this dietary change may lead to confusion, even in patients who received nutrition education before surgery. To be successful with weight loss and maintenance following surgery, patients must know how to plan and prepare meals that provide a proper balance of nutrients.
Weight loss surgery patients are encouraged to stay in contact with their surgical team, including the bariatric dietitian. On occasion, though, patients lose contact with this team and seek help from professionals who aren’t accustomed to working with their postsurgical population. Therefore, it’s important that all dietitians have a general idea of what the long-term dietary requirements are after weight loss surgery.
Once patients are cleared to consume regular-consistency food, the emphasis remains on meeting adequate protein needs to spare muscle wasting during periods of weight loss. The common daily protein recommendation for bariatric patients is 60 g to 80 g. Patients are encouraged to consume whole foods rather than processed foods to obtain the most nutrients per meal. Patients may need to temporarily rely on protein supplements in the form of protein shakes to help meet protein needs. As patients gradually increase their portion sizes, they can meet protein requirements through solid food alone.
Carbohydrate intake tends to be very low initially after surgery because of the body’s low tolerance and the postsurgical emphasis on protein. Over time, carbohydrate intake will increase as patients gradually consume more food. Encourage patients to choose whole food sources such as fruit and starchy vegetables. Grain products can be problematic and difficult to tolerate in the early stages. For this reason, many weight loss surgery patients will avoid bread, rice, and pasta.
Post bariatric surgery fat recommendations are similar to those of the general population. Emphasize more healthful fats such as unsaturated fat and fat from whole food sources such as nuts and avocado.
Portion tolerance varies from patient to patient; however, the initial average meal size is 1/4 to 1/2 cup of food at each meal. Over time, patients likely will be able to eat larger portions and may be able to tolerate 1 to 1 1/2 cups of food per meal long term. However, the density of food can affect the amount of food consumed at each meal. Liquid or easily digested foods won’t take up as much room in the stomach as foods that are slower to digest. For example, 1/2 cup yogurt won’t provide the same satiety as 1/2 cup chicken.
Some patients experience intolerance to certain foods following weight loss surgery. The type of food that isn’t digested well may vary from patient to patient, but the foods that are the most problematic include bread, pasta, rice, tough meats, and hard or stringy fruit and vegetables. In addition, patients undergoing gastric bypass or duodenal switch may experience dumping syndrome from simple sugar consumption.
Dietitians can help patients be successful long term by teaching meal planning skills and basic nutrition principles before surgery.
— Jennifer Pullman, MA, RDN, LDN, has been a practicing dietitian since 2001. Since 2007 she has worked solely with patients undergoing a variety of weight loss procedures, including Roux-En-Y gastric bypass, lap-band, and sleeve gastrectomy. In addition to her work as a bariatric dietitian, she publishes two blogs: Nourished Simply, a general nutrition and recipe blog, and Bariatric Bits, a website dedicated to providing nutrition information for weight loss surgery patients.