Updated 07 August 2014

Pros, cons of weight-loss surgery

You and your doctor have agreed: surgery could be the answer to your weight-loss problems. But what are the disadvantages – and the possible risks – of bariatric surgery?

You and your doctor have agreed: surgery could be the answer to your weight-loss problems.

But what are the disadvantages – and the possible risks – of bariatric surgery? And how will this operation change your life?

Risks of bariatric surgery
Any operation that requires an anaesthetic, which takes between 1 and 3,5 hours to complete, is potentially dangerous.

If one also keeps in mind that patients who undergo these operations are morbidly obese and often suffer from a variety of associated complications such as respiratory disorders, diabetes and heart disease, the risks may be even more.,/p>

According to scientific literature, the following risks are associated with bariatric surgery:

a) During or shortly after the operation:

  • Pulmonary embolism (a blood clot in the lungs), which accounts for up to 70% of deaths that occur during or immediately after surgery
  • Major wound infections
  • Peritonitis (inflammation of the membrane of the abdominal cavity)
  • Narrowing of the entrance to the stomach
  • Abscesses
  • Slippage of the gastric band or staples which then require re-operation

b) After surgery

  • Vomiting
  • Dysphagia (inability to eat)
  • Hernia
  • Heartburn
  • Diarrhoea
  • Dumping syndrome (see below)
  • Malnutrition
  • Vitamin and mineral deficiencies (see below)
  • Regain of weight that has been lost

(Msika (2003), Sugermann (2001), Sugermann et al (2003)).

c) Associated factors
A bariatric operation can cost R80 000 or more, depending on the length of your stay in hospital and any complications that may occur.

At the moment, most South African medical aids don’t cover bariatric surgery.

Dumping syndrome
According to Krause (2000), dumping syndrome is "a complex physiological response to larger than normal amounts of food and liquid in the upper parts of the small intestine" due to changes in the rate at which the stomach is emptied.

The symptoms associated with dumping syndrome usually start off with mild effects that include a feeling of fullness and nausea 10 to 20 minutes after eating. Patients may also experience flushing, heart palpitations, fainting, sweating and the urge to sit or lie down.

About one hour after eating, patients may develop abdominal bloating, winds, cramps and abdominal pain and diarrhoea.

Finally, the most extreme stage of dumping syndrome can cause hypoglycaemia (low blood sugar). Patients may perspire, feel anxiety, weakness, shakiness, or hunger, and may be unable to concentrate.

Ironically, the fact that these symptoms can be so severe, can act as a strong motivation to patients to stick to the post-operative dietary rules that they will need to follow for the rest of their lives.

To avoid dumping syndrome, the following guidelines should be applied:

  • Eat only small meals, which should be spread throughout the entire day (6-8 meals per day).
  • Eat mainly high-protein, low-fat foods.
  • Include some dietary fibre if you find that you can tolerate this (e.g. brown bread, oats, brown rice).
  • Try to rest or lie down one hour after your meals to slow down stomach emptying.
  • Avoid drinking liquids with your meals, but make sure that you have small quantities of liquid (no more than 100ml), all day long between meals to prevent dehydration.
  • Avoid cold drinks, juices, pies, cakes, biscuits and frozen desserts or any very sweet foods.
  • If you find that milk and dairy products don’t agree with you or worsen the symptoms of dumping syndrome, then you may have to avoid them. In such cases, it is essential to take a calcium supplement. Cheese and yoghurt can usually be eaten without discomfort.

Vitamin and mineral deficiencies
Post-operative vitamin and mineral deficiencies are common in patients who have undergone bariatric surgery, namely:

  • Iron deficiency which can cause anaemia (this is particularly common in female patients who menstruate)
  • Vitamin B12 deficiency, which can also lead to megaloblastic anaemia
  • Calcium deficiency, which may cause osteoporosis later in life
  • Folic acid deficiency

Most bariatric surgery patients need to take vitamin and minerals supplements for the rest of their lives and your surgeon or dietician will advise you which products to use. Regular monitoring of vitamin and mineral levels in the blood is a recommended precautionary measure to pinpoint potential deficiencies.

Advantages of bariatric surgery
The greatest advantage of bariatric surgery is, of course, the significant weight loss that morbidly obese patients achieve. Losses of up to 120kg have been reported.

As these patients lose weight, many of their so-called co-morbidities either disappear or improve dramatically, for example type 2 diabetics may find that they no longer have to take medication and can control their condition with diet alone.

Improvements are also seen in: hypertension, sleep apnoea, obesity hyperventilation syndrome, gastro-oesophageal reflux, venous stasis, urinary incontinence, female sexual hormone dysfunction (e.g. polycystic ovarian disease), degenerative joint disease, and most other obesity-related diseases.

Any patient who has lost a third to half of his/her body weight will naturally be more mobile and active.

In addition, patients experience a great increase in self-esteem, less depression and anxiety, and feel much more self-confident. Patients also find it easier to get jobs and find romantic partners.

How to find a bariatric surgeon in South Africa
Readers often ask me how they can find a bariatric surgeon in South Africa. If your GP cannot refer you, then you can contact the Association of Surgeons of SA. You can phone the secretary of the Association on 0860-7874-366 or send an e-mail to Susan Parks at to find out which surgeons you can contact for these operations.

The vital role of the dietician
If you decide to have bariatric surgery and your surgeon gives the go-ahead, it is essential that you also consult a clinical dietician – preferably before you have the operation. You are going to need the assistance of a dietician for the entire post-operative period.

Initially, you will only be allowed a liquid diet for two weeks. Then you will have to eat a pureed diet for two weeks and a soft diet for a month.

Once you have stabilised, you will also require follow-up advice on what to eat and how to prevent vitamin and mineral deficiencies. Your dietician will assist you every step of the way, so make use of her/his services.

Visit the Association for Dietetics in SA website and click on "Find a Dietician" to find a dietician in your area.

Text copyright: Dr I.V. van Heerden, DietDoc
30 July 2007

(Cole, B (2007). When diets and exercise fail, surgery can help. Pretoria News, 20 July, p 11; Krause (2000). Food, Nutrition & Diet Therapy. 10th Edition. Mahan LK & Escott-Stump, S Editors. WB Saunders Co, Philadelphia; Nguyen, NT et al (2000). J Am Coll Surg, Vol 191(2):149-55; Misika S (2003). J Chir (Paris), Vol 140(1):4-21; Sugerman, HF (2001). J Assoc Acad Minor Phys, Vol 12(3):129-136; Sugerman, HF et al (2003). J Gastrointest Surg, Vol 7(1):102-7)

Read more:
Obesity: is surgery an option?
Obesity surgery can be fatal


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