All about eating before and after weight loss surgery

Have you been thinking about weight loss or bariatric surgery? You might have questions, like Do people have to follow a specific diet before surgery? What do people eat after they have weight loss surgery? How much can they eat? Do they have to take vitamin and mineral supplements? The information below will help answer these questions.

According to the most recent guidelines published by the American Society for Metabolic and Bariatric Surgery, “long-term studies have proven [metabolic and bariatric surgery (MBS)] an effective and durable treatment of severe obesity and its co-morbidities. Studies with long-term follow up … have consistently demonstrated that MBS produces superior weight loss outcomes compared with nonoperative treatments.”

Until they have their surgery scheduled, pre-surgery patients are recommended to follow the MyPlate guidelines. Imagine a plate divided into four quarters: half of the plate should be fruits and vegetables, about one-quarter should be lean protein, one-quarter should be grains (mostly whole grains), and there also should be a serving of low-fat or fat-free dairy at each meal.

After patients have completed all the steps necessary to receive weight loss surgery, they follow a liver-reducing diet for two weeks prior to surgery. This low-fat, low-carbohydrate, higher-protein diet helps shrink the size of the liver so that the surgeon has easier access to the stomach during surgery. Daily goals include 64 ounces of non-caffeinated, sugar-free fluids, 80-100 grams of protein, 1,000 calories and 50 grams of carbohydrates.

As is typical with most pre-surgery diets, patients who have weight loss surgery follow a clear liquid diet 48 hours before surgery. This includes broth, clear protein water and other sugar-free, non-caffeinated and non-carbonated beverages.

After weight loss surgery, patients have two main goals: 48-64 ounces of daily fluid and 60-80 grams of protein. The fluid goal is to help prevent dehydration. Protein is emphasized because it is used by the body for wound healing and repair after surgery. In addition, consuming enough protein helps patients use fat for energy while maintaining muscle tissue.

For approximately the first two weeks after surgery, patients will be on a full-liquid diet as they heal from the surgery. They will need to eat four or five times per day due to the reduced size of the stomach. The fluid goal can be met with non-caffeinated, non-carbonated and sugar-free beverages. Both ready-to-drink protein beverages or shakes made with protein powder can be used to help the patient reach their protein goals. The full liquid diet also includes low-fat/fat-free Greek yogurt, creamy soups and sugar-free gelatin.

The next stage of the diet has the same fluid and protein goals and has two phases that increase food texture. Patients still will be eating four to five times per day in two-to-three-ounce portions. In the first phase foods such as soft scrambled eggs, cottage cheese and mashed beans are consumed in addition to the protein drinks to help the patients reach their protein goal. In the second phase, tuna, soft-cooked vegetables, peanut butter and avocado can be consumed in small amounts.

In the fourth stage, the maintenance stage, patients consume foods as tolerated. They still have the same fluid and protein goals and are still eating four to five times each day. Patients focus first on protein (two-to-three-ounce servings), then vegetables and then other foods that have fiber, like fruits or whole grains. This is the recommended diet for the rest of their lives.

Since people who have had weight loss surgery eat less food overall and have had changes to the stomach, it is recommended that they take vitamin and mineral supplements daily.

Learn more about the Weight Loss and Metabolic Center at Baylor Medicine.

By Claire Edgemon, senior registered dietitian in the Michael E. DeBakey Department of Surgery