Welcome Collapse
Bariatric Surgery Collapse
Nutrition Collapse
QA Collapse
Article of the month Collapse




Renata Wilson R.D & Nicola Drabble R.D

Twelve weeks prior to surgery, extensive preoperative dietary education is given which includes dietary information that addresses pre- and post-operative diet stages, texture progression, and the importance of protein, hydration, and vitamin supplementation. Patients who are not willing to make these changes, or who do not seem to understand these requirements, may not be ready to undergo surgery.

A balanced, low energy eating plan is commenced to achieve initial weight loss. A preoperative weight loss of 5% to 10% is aimed for, specifically in patients with a BMI greater than 50 kg/m2, and those who suffer with obesity-related comorbidities. Weight loss before surgery reduces preoperative morbidity and the risk of perioperative complications. It also has the added benefit of reducing the size of an enlarged fat-infiltrated liver.

During this pre-operative phase, the patient is encouraged to consume a diet which is low in fat and refined carbohydrates (sugars). This eating plan can also be used after bariatric surgery. It forms the basis of good eating habits and successful weight loss as well as to reduce post operative dietary related complications such as diarrhoea and dumping syndrome. The dumping syndrome occurs when too much sugar or fat is eaten and the contents of the stomach are transported or ‘dumped’ into the small intestine too rapidly, causing symptoms such as sweating, dizziness, faintness, rapid weak pulse, diarrhoea and hypotension (low blood pressure).

Patients are encouraged to prepare meals so that 50% of the plate is filled with vegetables, 25% with lean protein (meat, fish, chicken, eggs, pulses and fat free dairy products), and the remaining 25% with complex carbohydrates (whole wheat breads, pasta, rice, potatoes and cereals). Patients will be guided to add more fruits, vegetables, whole grains, and beans into meals, as these foods have a high fiber and water content which will lengthen satiety and are generally the lowest in calories.

Patients who are required to follow a partial meal replacement diet, should choose meal replacements that have a balance of macronutrients, provide 180 to 200 calories per meal and 15 to 20 g of protein, and are low in sugar (≤16 g of sugar per 200 calories). The dietitian will advise on this. Portion-controlled meal replacements provide a release from complex dieting and produce successful, gradual weight loss. All patients should be encouraged to avoid last-minute binging before their surgery.

Any existing nutritional deficiencies are addressed pre-operatively. Calcium, potassium, iron, protein, albumin and Vitamin D are nutrients at risk. Hyperlipidaemia, raised glucose levels and non-alcoholic steato-hepatitis can also be improved with an adapted diet and lifestyle. In general, the aim is to establish better eating behaviour by encouraging the patient to consume 4 small meals per day, chew slowly and sip water in-between meals.
Carbonated drinks, coffee and alcohol should be avoided preoperatively, and 3 months post-operatively.

Carbohydrate Protein Fat
≈ 40% of total caloric intake ≈30% of total caloric intake ≈ 30% of total caloric intake
The total should not be less than 130 g/day   Choose mono- and polyunsaturated fats: olive oil, canola oil, nuts/seeds, fish, particularly those high in omega-3 fatty acids (eg, salmon, herring, trout, sardines, fresh tuna) 2 times/wk
A minimum of 20-35 g of fiber per day