Editor's Note: This article was originally written by Harry Lodge, M.D.
This is the third in a series on losing weight from our expert, Harry Lodge, co-author of Younger Next Year. You can check out his first post here.
People talk a lot about setpoints, and the biology of weight loss, but what exactly are setpoints?
The short answer is that no one knows for sure. The longer answer is that all biological systems try to maintain equilibrium around either a single point, or a very narrow range. This is true whether it's blood chemistry, body temperature, blood pressure, resting heart rate, or weight.
Some setpoints, such as your body temperature, are essentially fixed for life, but others change in response to circumstances. Biologically, this is supposed to set you up for optimal survival out in the natural world.
In the case of modern America, however, there's not much natural about our world, and in the case of weight management, this has come to be deeply counterproductive. Still, we're not likely to change our biology, so let's learn how to manage it.
In terms of weight, you have a set point, which for most people, seems to have a rough range of 10 pounds, meaning that you can gain or lose 5 pounds without much trouble. If this setpoint never changed, we wouldn't have the obesity epidemic we face today, but, unfortunately for us, it does change. It adapts to the fluctuations in your weight, but it adapts far more quickly, and more powerfully to upward fluctuations than to downward fluctuations.
In fact, in most people, it probably never fully adapts downward. That's a critically important concept. For many Americans, every step upward in weight you take creates a new, and semi-permanent setpoint. That leads to the first, and in some ways most important rule of weight management.
Last week: What to Expect in Your Weight Loss Journey
Next week: Never Gain Another Pound