Nutrition and Diet Phase


After bariatric surgery, you will need to make changes to your eating patterns. Upon your return home, you will be put on the Phase I Diet. Refer to your diet booklet for specific instructions and meal plans. Your postoperative diet will be progressed by your surgeon and dietician and will gradually transition to whole foods. It is important that you follow the progression and adhere to the specific instructions in order to maximize healing and minimize the risk of complications.

Your post-operative diet is divided into three phases: Liquids (Phase I), Softs (Phase II), and “Regular” Bariatric (Phase III). You can download our Nutrition Guidelines for Weight Loss Surgery and review the information below.

Diet phase

Phase I Diet:

Phase I consists of a full liquid diet. The most important aspect of the first months after surgery is to keep well hydrated. Aim for 64 ounces (8 cups) of water and other fluids daily by constantly sipping liquids. Do not gulp! Do not consume carbonated or high calorie sugary beverages. Get in the habit of carrying a beverage with you. You should never go a few hours without drinking anything. Constantly sip to avoid becoming dehydrated. Avoid fluids high in caffeine as they can increase your risk for dehydration. Your long-term protein goal is 60-80 grams per day, however during Phase I a more realistic and obtainable goal is 30-40 grams per day.

Acceptable liquids include water, broths, sugar-free gelatin, sugar-free popsicles, crystal light, skim milk, low-calorie protein drinks, and unsweetened flavor water. Please refer to your diet booklet for a more comprehensive list.

You will be on this phase for about the first 7-10 days after surgery, depending on your type of surgery and surgeon’s instructions.

Phase II Diet:

Phase II diet includes, soft, easily digestible foods. Expect to be on this phase for about four weeks. These foods may be slowly introduced into your diet. You must chew your food well. Choose soft meats/fish, soups, cooked vegetables and canned fruit (in juice or water). Remember to choose low fat or fat free dairy, lean meats and low sugar items.

Begin by eating 3 small meals per day. Do not snack throughout the day. Eat the protein portion of your meals first and get in the habit of eating at least 2 ounces of protein rich food at each meal. (Refer to the diet book for protein rich foods). Eat slowly, take small bites and put down your spoon or fork while chewing. It is important to stop eating as soon as you feel full – this may occur after only 3 bites of food! If you experience difficulty with thicker foods, return to liquids for 1-2 days and try again.

Everyone’s tolerance is unique and you may have more difficulties with some foods than others. Moist, well-cooked foods are initially tolerated better. Please see the diet book for specific meal plans and suggested foods. If at any time, you experience difficulty, call our office!

Phase III Diet:

Phase III diet is a "regular” bariatric diet. You will be able to eat foods of regular consistency. However, this does not mean you should go back to your old eating habits. Continue to eat nutrient rich foods such as lean meats, poultry, pork, low fat dairy products, vegetables and fruit."

Contact us

Schedule or find out more about our bariatric surgery services by calling (412) 235-5900 (select option 1).