Weight reduction surgery is stepwise procedure that is done to correct obesity in persons that are struggling with excess weight. It is also termed bariatric surgery. During the procedure, it is often necessary to reduce the size of the stomach as well through a number of techniques. This may be done either by use of sleeve gastrectomy or by use of a special gastric band. The former cuts off some portion whereas the latter only shrinks the volume. The bariatric procedure greatly benefits people struggling with conditions such as hypertension and diabetes.

It is recommended for people with a minimum body mass index of forty and those with existing medical conditions in which obesity is a predisposing factor. Such conditions may include diabetes, hyperlipidaemia, hypertension and impaired glucose tolerance. Surgery is considered when all other programs including exercise, diet and drug therapy have failed.

There are a number of advantages and disadvantages associated with this surgery. All these need to be taken into account before a decision is made on whether the procedure is necessary. Some of the possible complications that should be anticipated include malabsorption of nutrients and gall bladder disease. The risk of depression is also high and as such these persons should be counselled.

Surgical procedures are grouped in to three main categories. These are malabsorptive, restrictive or mixed. The most commonly performed is the malabsorptive procedure. Malabsorptive operations aim at creating a physiological state of malabsorption. Biliopancreatic diversion combined with duodenal switch (BDS/DS) is one such undertaking. A section of the stomach is resected, creating a smaller pouch which is then directly connected to the ileum, bypassing the duodenum and jejunum. The malabsorption that results can be severe enough to cause serious deficiency diseases such as osteoporosis and anemia unless vitamins and mineral supplements are administered.

Restrictive procedures are done to reduce the amount of food eaten by reducing the size of the stomach. The person that has had this surgery will usually experience earlier satiety than was the case in the previously. A common technique used to achieve this is the vertical banded gastroplasty. In this technique, permanent staples are put on the stomach and this effectively reduces the volume.

Another effective technique that is restrictive in nature is what is referred to as sleeve gastrectomy. As much as 15% of the stomach can be resected by use of this technique. Most of this portion is taken from the greater curvature. This technique transforms it into a tubular shape. Laparoscopes are often used to improve on the accuracy.

The diet of the patient after surgery becomes restricted to liquid foods such as broth, fruit juice and gelatin desserts that are sugar free. This kind of diet is maintained until the alimentary canal recovers from the surgery. The next diet is composed of blended substances which are sugar free, consisting of foods such as cream soup, skimmed milk, protein drinks among others.

Adverse effects of weight reduction surgery are common. Due to reduced calcium absorption, patients can develop metabolic bone disease in form of secondary hyperparathyroidism and osteopenia. Rapid weight loss can also result in gallstones. In addition, reduced absorption of nutrients such as thiamine, folate, iron and vitamin B12 can lead to nutritional derangements. Defective renal handling has also been reported.