Originally put forward in the early 80’s, Set Point Theory has a major role in many studies on diet, exercise and weight management. Whether you accept the theory or otherwise – there are believers on either side of the fence – its concepts are valuable in understanding diet, exercise and weight.
Set point theory says that the body defines an ideal (efficient, healthy) weight and shape for each individual. It defines a set point - a standard level at which all major factors interact, including importantly, calorie burn, fat processing and metabolic rate. It tries to maintain that point through all those complex set of interactions between our internal systems.
It’s an evolutionary defence mechanism. It makes adjustments to our settings and processes to make us better survive the changes that it becomes aware of. While it's trying to keep us at our set point with constant adjustments, we're often changing things. For instance when we start a diet or quickly reduce calorie intake, our set point heads down until the body recognizes (or senses) it’s getting starved, and slows up our metabolism, and moves more calories to fat stores in preparation for tough times that seem to be coming.
We're then using fewer calories, despite the same level of activity (we might not feel tired) and with more calories now moved to fat stores, we don’t lose the weight we thought we would. In other words, our set point control mechanism acts as a supervisor for fat storage – adding to fat stores when our calorie intake is lower, and by sending it out to our muscles for ready burning when it’s higher.
In fact, it’s easy, after a lot of exercise and some reduced eating, to find you’re not losing weight any more; that you’ve plateaued, as they say. This would seem to be evidence of Set Point Theory in action. Doing all the right things and finding you've stopped losing weight can be frustrating!
However, Set Point remains very much theory rather than accepted principle, and conjecture will continue for some time because the complexity of the factors involved makes it difficult to prove or disprove.
Some recent studies have questioned it. Studies of chronic weight gainers who had controlled diets and significant exercise which supported Set Point theory have since been observed to have missed important factors. And how many factors are really involved? It can be an awful lot, it seems, and to run valid tests would seem nearly impossible: the combination of how, when and what we eat in combination with many other factors - when and how we exercise being just two – is very complex.
Importantly, there seems to be a strong belief that if there is a Set Point, you can move it by concerted activity, for example dietary and exercise changes over prolonged periods. And we do know that change and variety to both food and diet can eliminate the plateau effect, and get us onto the path to lower weight if that’s what we’re after.
It’s helpful to know why sometimes it ain’t easy, though.
Set Point Theory - What It Is and Why It's Important