888-344-3916

Pre Op Diet for Lap Band, Gastric Sleeve, Gastric Bypass and Duodenal Switch


Hi, my name is Nina and welcome to Mexicali Bariatric Center. Today I would like to talk to you about pre op diets. As you  already know we perform many types of surgeries and we’ll start with the pre op diet we ask our patients to do for the gastric sleeve and the lap band. For the gastric sleeve we don’t ask for an all-liquid diet. What we do instead is a high protein low carb diet. Before we schedule the procedure we ask our patients to to fill a medical form so the doctors can know more about them. These are reviewed by the internal medicine doctor and the surgeon, and they give a specific pre op diet to each patient. But the most common is a high protein low carb diet, which is not a liquid diet, for a period of seven, ten days, to 2 weeks. 

There are some circumstances where we have patients with a high BMI (60-90), for them we do a combination of liquid and solid diet. What we usually say to patients is that they have to start with a protein shake in the morning, they do one meal in the day, then another protein shake at night. They are able to have a couple of snacks during the day. Sugar free jelly, for example. We also give them a goal for the amount of protein ingested during the day, for the maximum amount of carbs and daily water intake. This is for the lap band and the gastric sleeve. 

For the gastric bypass it is a little bit different. Like in the other procedures, depending on the BMI we may start with a combination of a liquid and solid diet. Let’s say a patient gets a week or two of a liquid/solid pre op diet, then we ask for an all-liquid only diet 3 days before surgery with special guidelines for this part of the diet. As you know, with the gastric bypass the intestines are manipulated so the doctors need them to be in shape for surgery. 

Now, for the pre op diet before Duodenal Switch surgery, if we need patients to lower their BMI’s we start with a period of  the combination of solid and liquid diet, and the last 5 days prior  to surgery we do an all-liquid diet. We get some patients with very high BMIs and with them the mixed diet may take longer than two weeks, but as with other patients the last 5 days they need to follow an all-liquid diet. We also give our patients a list of foods to avoid two weeks before surgery that might fit into the pre op diet. 

Many patients ask us what happens if they want to follow these dietary guidelines for a longer time and that’s perfect. The longer you do it, the better. Risk will be reduced, the liver will shrink more… but patients need to be realistic. If you want to do it for four weeks instead of two, that’s fine. But make sure that those two weeks before surgery you are extra strict. Please, no cheating! It is important to not bend the rules and follow them strictly before surgery and according to what the doctor said. 

I hope this helps and hope to see you soon.