When the weight control mechanism goes wrong, it’s as if the part in the brain controlling this amazingly complex mechanism has been re-set. It thinks that the normal amount of fat for that person should be say 50%, rather than say 21%, which would be their normal fat. So weight can be lost for a while, then the control centre gets alarmed, as it thinks there is not enough fat to survive! So a whole series of chemical processes are set in motion to regain that fat. These processes occur without us knowing, and are beyond our control, just like heart beats and breathing. We can influence them for a while, but we cannot stop them.

 

We have very limited medical ability to control this system. Long term drug use (pharmacological therapy) is very unlikely to lose more than 10% of body weight, and there are side effects for many people. Pharmacological treatment (in concert with supervised behavioural modification) include appetite suppression, e.g. the SNRI, sibutramine (Reductil®), or the amphetamine/phenethylamine suppressor, phentermine (Duromine®)  and lastly intestinal fat absorption inhibition, e.g. orlistat (Xenical®). Addition of currently approved weight-loss medications to lifestyle modification provides little additional benefit, probably due to dose-limiting side effects and poor compliance over the long term.

 

Thus, we resort to bariatric procedures because long-term weight loss is reproducibly achieved through them:

  • 36-87% average excess weight loss at 24 months with laparoscopic adjustable gastric banding
  • 68-80% average excess weight loss at more than 12 months with Sleeve gastrectomy or Roux-en-Y gastric bypass

 

It is vital to understand that surgery is done to improve health and cure or improve illness. To do that, we have to get rid of fat. It is not a purely cosmetic option.

If you have read all of this so far, take a break as it gets a bit more complex from here on!