GUEST POST: I am currently in Rio de Janeiro, speaking at the 21st World Congress of the International Federation for the Surgery of Obesity & Metabolic Disorders – IFSO 2016.
As Lee Kaplan from Harvard University reminded the audience, obesity is a disease of energy homeostasis, where everything seems to be working just fine, except that the “setpoint” of the system is set too high.
Kaplan used the analogy of the temperature in a room, where the thermostat is set too high – say to 30 Centigrade.
Everything else in the room works just fine: nothing wrong with the heater, or the air-conditioning, or the ventilation system, or the isolation. In fact, even the thermostat is working just fine doing its job – except that it is set too high!
Dieting would be like tearing open a window to lower the temperature in the room. Yes, if you open the window, things may cool down, but the thermostat will only make the heating work extra hard trying to heat the room and, once you close the window, the thermostat will rapidly bring the temperature back to 30 Centigrade (or come off your diet).
So how do we reset the set point?
Well, that appears to be exactly what bariatric surgery does to the system – it somehow manages to lower the set point, allowing the body to regulate its weight at a lower level than before (something that does not happen when you lose weight simply with diet and exercise).
How exactly surgery does this, remains unclear, but there is no doubt that this happens and there are a lot of experiments showing that after sugery, the body actively regulates body weight at a lower “setpoint”.
Unfortunately, this “resetting” is not permanent.
If you reverse the surgery, the body goes right back to regulating its weight at the higher level, resulting in the rapid weight regain, which is why I consider obesity surgery a “treatment” rather than a “cure”.
Kaplan went on to talk about the role of the bacteriome and bile acid metabolism (both dramatically changes with bariatric surgery – but very little with diet and exercise).
Figuring out how bariatric surgery changes the setpoint (even temporarily) will hopefully lead to new medical treatments for obesity.
Till then, anyone losing weight (no matter what diet, exercise, or medication) needs to remember that they stand to regain the weight, the minute they stop the “treatment”.
Feature Courtesy of Dr. Sharma’s Obesity Notes