Why can’t an alcoholic stop drinking? Why can’t a smoker stop smoking?
It’s the same with an overweight to reduce weight as the person is always hungry and wanting food.
Marilyn Walsh, a 38-year-old housewife from London, was unsuccessful to reduce her weight through dieting.
What is different about people like Marilyn?
Dr Carel Le Roux, of Imperial College and King’s College Hospital in London, studies obesity and the underlying processes that help control the decisions you all make to eat or overeat and found that the gut can actually talk to the brain and influence how hungry you are, or how full you are.
In 2001, the research unit at Imperial discovered two previously unknown hormones called PYY and ghrelin which seem to play a part in your sensations of fullness and hunger. Ghrelin was linked to the sensation of hunger and PYY to fullness.
For many obese patients, concentrations of hunger hormones are in many cases significantly different from those in thin people. Their PYY tells them when to stop eating, is not working properly. Instead their hormones are making them feel permanently hungry – just as Marilyn had described.
Last October, Marilyn was admitted to King’s College Hospital to undergo a stomach bypass operation. The surgery involved cutting her stomach in two, and connecting only the smaller part to her small intestines. Effectively her stomach was reduced from the size of a fist to the size of a thumb. After the surgery, she was never able to eat a full meal again, profoundly affecting her weight.
According to research by Dr Le Roux, such operation has a powerful and unexpected side-effect. While reducing her stomach, the operation also re-balanced her hormones. And for the first time in her life, Marilyn stopped thinking like a fat person and behave like a slim one.
A few weeks after her operation, Marilyn had lost more than four stone (earlier 21 stone). Significantly her taste had changed.
Psychiatrist Dr Samantha Scholtz has been researching how the brain responds to different kinds of food. Stimulated areas of the brain include the orbital frontal cortex, associated with reward, and other areas associated with addiction and an emotional response to food.
The patients who had undergone gastric bypass surgery had their brain activity totally changed. Their reaction to seeing high-calorie food is different, and that would ultimately drive their choices of food, so that they stop having that battle with food. You can put things into the bowel or you can use injections or pills that actually will do what the operations are achieving. Now if you do that, it opens up the whole science of obesity.