Causes of Obesity

Health Risks of Morbid Obesity

According to the NSW Department of Health, overweight and obesity is a serious, chronic medical condition.

Morbid obesity brings with it an increased risk for a shorter life expectancy. For individuals whose weight exceeds 50% above their ideal body weight, the risk of an early death is doubled compared to non-obese individuals. (3)

Causes of Overweight and Obesity

The following have been identified as important contributing factors in becoming overweight or obese (4)

  • Energy intake from food exceeds energy expenditure, but obesity is not simply a result of overeating.
  • Biological factors such as age, sex, hormonal and genetics.
  • Behavioural influences such as learnt habits, emotions, attitudes, beliefs and thought process.
  • Environmental/societal influences such as social, political and economic environment.
  • Metabolism and the potential effects of a 'set point'. (7)
  • Some medical conditions such as hypothyroidism. (16)

It is very important to understand that all current medical interventions, including weight loss surgery, should not be considered medical cures. Rather they are attempts to reduce the effects of excessive weight and alleviate the serious physical, emotional and social consequences of morbid obesity.

Contributing Factors of Morbid Obesity

There are many factors that contribute to the development of obesity including genetic, hereditary, environmental, metabolic and eating disorders. There are also certain medical conditions that may result in obesity like intake of steroids and hypothyroidism.

We have included additional information for the following contributing factors:

Biological Factors - learn a bit more about how your genes contribute to obesity
The Pima Paradox - info about the Pima Indians and genetic obesity links
Environmental Factors and Metabolism - more about lifestyle and your bodies metabolic needs.
Eating Disorders & Medical Conditions - your doctor is the best person to explain any conditions that may affect your ability to lose weight or have weight loss surgery.

Treatment Options

Non-Surgical Treatment

For anyone who has considered a weight loss program, there is certainly no shortage of choices. Most non-surgical weight loss programs are based on some combination of diet/behavior modification and regular exercise. Unfortunately, even the most effective interventions have proven to be effective for only a small percentage of patients. Research has shown that non-operative methods alone have not been effective in achieving significant long-term weight loss in severely obese adults . (3)

The main non-surgical treatment options are:

  • Diet and behaviour modification
  • Exercise
  • Over-the-counter & prescription drugs

In 2002, Australian researchers reviewed the effectiveness of treatments available for severe or 'morbid' obesity and concluded that surgery was the only effective option available at the time of the report. (8)

Diet & Behaviour Modification

There are literally hundreds of weight loss diets available. Doctors who prescribe and supervise diets for their patients usually create a customized program with the goal of greatly restricting calorie intake while maintaining nutrition.

These diets fall into two basic categories:

Low-Calorie Diets (LCDs) are individually planned so that the patient takes in 500 to 1,000 fewer calories a day than he or she burns.

Very-Low-Calorie Diets (VLCDs) typically limit caloric intake to 400 to 800 a day and feature high-protein, low-fat liquids. Studies show that the long-term results of Very-Low-Calorie Diets (VLCDs) vary widely, but weight regain is common. (9)

Behavior modification uses therapy to help patients change their eating and exercise habits. Combining a Very-Low-Calorie Diet (VLCD) with behavior therapy and physical activity may help increase weight loss and slow weight regain. In the long term, however, Very-Low-Calorie Diets (VLCDs) are no more effective than more modest dietary restrictions. (9)

If diet and behavior modifications have failed you and surgery is your next option, it is important to understand that diet and behavior modification will be instrumental to sustained weight loss after your surgery. The surgery itself is only a tool to get your body started losing weight - complying with diet and behavior modifications required by most surgeons would determine your ultimate success.

Surgical Treatment options

Tube Gastrectomy

This is a relatively new approach. It is the first component of the duodenal switch operation and involves removing the lateral 2/3rds of the stomach with a stapling device. It can be done laparoscopically ( keyhole surgery) but is not reversible. It basically leaves a stomach tube instead of a stomach sack.

Find out more about Tube Gastrectomy with the following links.

Patient Info handout

Bilio Pancreatic Diversion

These operations combines removal or exclusion of 2/3rds of the stomach along with a long intestinal bypass which significantly reduces the absorption of fat. The capacity to eat is greater than with the other operations, and the eventual weight loss is the best of all the operations but if fatty foods are overeaten e.g. a hamburger and fries then diarrhoea and foul flatus will result.

Gastric Bypass

Here a small stomach pouch is created to restrict food intake. Next, a Y-shaped section of the small intestine is attached to the pouch to allow food to bypass the lower stomach, the duodenum (the first segment of the small intestine), and the first portion of the jejunum (the second segment of the small intestine). This bypass reduces the absorption of nutrients and thereby reduces the calorie intake.

Find out more about Gastric Bypass with the following links.

Patient Info handout