Bariatric Journal

Bariatric Surgery Diet Guide

The development of obesity is the result of interaction between genetic make-up of an individual and dietary habit. While an individual might have hereditary tendency to be obese, appropriate diet may be used to maintain a healthy weight. This is the rationale behind most non-surgical weight loss programs. However, bariatric surgery provides structural or functional alteration of the gut which limits food intake and absorption and when complemented by appropriate diet result in satisfactory weight loss. One should not think that bariatric surgery will result in adequate weight loss without healthy food. Those who failed to maintain a healthy diet always have small weight loss or even weight gain.

Bariatric surgery diet can be designed for you by your dietician and is based on personal principles. The cause of obesity is excess food intake beyond what the body requires. Therefore, the diet is in a quantity that is just/less than sufficient for optimal body function. Muscle building is essential after bariatric surgery as it increases energy consumption at rest as well as during exercise. With reduced intake, increase in energy consumption will require the mobilization of fat for energy production resulting in weight loss. In summary, the bariatric diet should have the following characteristics;

  • High protein content with low carbohydrate and fat
  • Carbohydrate with high fiber contents
  • No refined sugar or artificial sweeteners
  • Adequate water intake but separated from the meal by at least 30minutes
  • Minimal/no snaking
  • The gradual transition from clear fluids to solid diet after surgery
  • Vitamin supplements
  • Small food at a time
  • Avoidance of alcohol and carbonated drinks

Bariatric diet can be divided into pre-op and post-op diets. The pre-op diet is commenced before surgery. If you are planning to get your operation funded through insurance, you may need to present evidence of a medically supervised dietary program which will demonstrate your complete readiness and probability of sustaining such diet after surgery.

Also, pre-op weight loss diet will lead to some weight loss which will reduce your operative risk. Studies have shown that the higher the BMI before surgery, the more the risk of complications both during and after surgery. Furthermore, this diet will provide the body with the necessary nutrients required for wound healing. Studies have also demonstrated that pre-op dietary program helps a lot in maintaining the post-op nutritional plan.

  • The pre-op diet will be made up of high protein content with low carbohydrate and low fat.
  • You will need to take plenty of fluid.
  • Few days before surgery, your diet will be mainly liquid with total daily energy consumption less than
  • 1000 calorie with some bariatric vitamin supplements.
  • You may be asked to stop oral intake 6 hours before your surgery.

After surgery, you will be guided by your dietician/nutritionist on the appropriate diet. Strict adherence to this plan is central to your post-op recovery and weight loss goal. It will also reduce the probability of adverse side effects after surgery. The post-bariatric surgery diet starts with clear liquid with a gradual transition to solid foods.

The manipulation of the digestive tract during bariatric surgery causes a temporary gut paralysis. This is the main reason you will not be allowed to eat immediately after surgery. The duration of this gut paralysis varies. Those with malabsorptive surgery involving anatomical re-fashioning of the small intestine may not be able to commence feeding until 48hours after the operation. Passage of flatus or stool, feeling of hunger and the return of bowel sounds are evidence that the gut has recovered from the temporary paralysis. Wait for your surgeon’s directive before you commence feeding.

Post-bariatric surgery protein requirement is a bit higher as protein is needed for healing. Muscles are also composed of protein, and there is need to build your muscles after bariatric surgery to increase your energy consumption at rest (BMR). Adequate protein intake after bariatric surgery is therefore essential. The protein intake should be at least 60g per day. The American Society for Bariatric and Metabolic Surgery recommends at least 60grams of protein per day after bariatric surgery. This should be taken in smaller quantities across multiple meals as the body can only absorb about 30grams at a time. You can prepare your protein drink (shake) with a protein powder supplement or use a liquid protein supplement.

Some examples of the liquid protein supplements include; premier protein, muscle milk light, and GNC total lean. Go for those with less sugar (<15grams), low calorie (not higher than 250 calories). Choose a supplement with whey protein.

You will only be able to take thin liquid diet in the first week after surgery. This should commence with sips and gradually increase it. It is advisable that you make at least 3 liters of fluid intake per day to avoid getting dehydrated and to prevent constipation. Liquid diet during this period includes unsweetened fruit juice, skimmed milk, and blended fruit juice. The quantity of these foods should be as prescribed by your surgeon.

During the 2nd-3rd week post-surgery, the diet should be composed of soft foods with no lumps. Examples include fats free yogurt, mashed potatoes, blended, baked bean, thick, smooth soup, etc. you can eat small quantity at a time for about 4-5times daily.

Semisolid diet can be taken by the 4th-week post-op. Beans, cooked vegetables, fish, eggs, etc. can be made during this stage.

By the 5th week, you may start taking steady diets. At this stage, your stomach should be fit to handle solid foods, and you can return to three meals per day with a little snack.

Avoid carbonated beverages. They contain refined sugar and will be counterproductive to your weight reduction goal. They also cause diuresis and may tilt you toward dehydration. Coffee should be avoided as it is acidic and may cause gastric reflux.

Multivitamins (vitamins B12, D) and mineral supplements (zinc, iron, and calcium) are essential after surgery as you may be struggling to eat and your diet may not supply the appropriate quantity of those micronutrients. Also if your procedure is malabsorptive, deficiency may occur due to poor nutrient absorption.

Some people find certain foods challenging to eat following bariatric surgery. Such foods should be avoided. They can be re-introduced once the patient is more comfortable with them. Joining a bariatric surgery forum will help you with motivation and support required to sustain your dietary plan.


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