Obesity is an unhealthy excess of body weight and fat. It has become an epidemic of modern day life. In Australia today, nearly 60 percent of adults are overweight or obese, and four to six percent suffer morbid obesity. More and more of our children are becoming obese.
Our ability to control our weight is a result of a complex interaction between evolutional biology, our genes and the environment in which we live. We evolved as hunters and gatherers from a low-energy environment thousands of years ago, where food was scarce, to an obesogenic one today. Biologically, we developed the ability to store excess energy as fat which we used in times of need. Today there is no biological need to store fat as food is plentiful. But we live in an obesogenic environment in which we consume more energy than we use, and fat storage is the result. Those of us who have a poor tolerance to this obesogenic environment, because of our genes, will become overweight or obese.
A measure of obesity is the Body Mass Index (BMI)
Have you ever tried to lose weight and found it quickly comes back? You’re not alone.
The problem with obesity is that once we store a certain amount of fat, our brain keeps us fat because it was a means for survival in the past. We know from epidemiological studies that our brain defends the heaviest weight we have been via the hypothalamus, which is the control centre in the brain. Our brain sets and defends this weight, known as our “set point”, even though there is no longer a biological need to do this in our current environment. So, when we try to lose weight by dieting, the weight quickly returns. This is often called “yoyo” dieting.
This isn’t your fault.
Obesity and the inability to lose weight does not come down to gluttony or poor self-control. The problem is that from a biological perspective, our brain is defending our fat stores and heaviest weight because it evolved when we were hunters and gatherers. Our brains have not yet evolved to understand that in the 21st century, where we no longer need to hunt for food; it is in fact plentiful and easily finds us.
Here’s where we come in.
Bariatric, or weight loss surgery, works by disrupting some of the biological mechanisms that keep us fat and thus disarming our set point. Some of these mechanisms are known but many are still not fully understood and are actively being researched.
What we do know is that many studies have shown that weight loss surgery, together with lifestyle changes, is the most beneficial and cost-effective treatment of obesity and related illnesses.