What is Body Weight Set Point Theory (and Can You Change It)?
Understanding Body Weight Set Point Theory
You may have heard the term “body weight set point theory” at some point and, without considering the details beyond its name, accepted it as a scientific truth to explain why you have struggled with losing and regaining body fat cyclically for however long you have been in pursuit of physical change. However, the nuance very much matters (a core belief we hold about all health-related topics at KLN!), so let’s take a closer look at body weight set point theory’s origins, definition, truths, and oversights.
Body weight set point theory was first proposed by two nutritional researchers, William Bennett and Joel Gurin, in 1982, expanding upon previous research and theories on bodily homeostasis by G.C. Kennedy three decades earlier. The theory’s platform is that the human body has a genetically pre-determined weight range that it fights to maintain through hormone signaling in response to weight loss or gain, which poses challenges to maintaining bigger weight loss or gain goals long term.
What body weight set point theory gets right
The theory’s underscoring of the role that both genetics and biology play in one’s ease in achieving weight change and future maintenance is inarguable. Genetics can determine factors that we can see and understand play a role in how much we weigh, such as height (more height = more bone mass = more skeletal weight), as well as ones that we may have never considered, such as organ size (which more directly plays a role in basal metabolic rate). Biology is perhaps the heavier hitter to consider though. Since the dawn of time, the human body’s primary aim has been to stay alive, with the primary threat to that aim being starvation. And although our consciousness and environment have evolved to be what they are in modern times, the presence of weight loss will still cause metabolic rate to slow as a form of adaptation to support survival (or “survival”). The body becomes more efficient with both active and passive movement, as well as conservative with how much energy expenditure is allotted to its basic upkeep on a cellular level.
Where genetics and biology team up in this pursuit: our satiety hormone, leptin, will become lower and our hunger hormone, ghrelin, will increase to drive hunger higher in hopes of consuming more calories to, in turn, regain lost weight. How impactful those drives are felt has a genetic component. On the other end of the spectrum, in the presence of weight gain to a certain extent, the body will become more liberal with its energy expenditure and leptin will increase while ghrelin decreases to regulate appetite in hopes of stabilizing at a maintenance point.
In sum, a number of mechanisms work together to influence metabolism and create what can be viewed as a “thermostat” of sorts for our individual bodies to regulate weight changes.
What Body Weight Set Point Theory Overlooks
Bennett and Gurin overlooked factors beyond genetics and biological factors that can, in isolation or combination, override their theory. Those were environmental factors such as:
Where somebody lives in the world: the layout and/or safety of their neighborhood, weather and air temperature throughout the year, etc.
What types of foods somebody may or may not have access to
How somebody’s culture and/or social circle influences their food choices
What type of job somebody holds: what the nature of their job is, how much income they earn, etc.
All have influence and call to mind the debate of “nature vs. nurture” in the context of weight. In an age where it can be so easy to override satiety cues and remain sedentary, genetics and biology simply cannot be the only considerations.
Additionally, one's body composition (ratio of lean tissue to fat mass) can be influenced by way of guided nutrition choices and appropriate exercise modalities for the goal of achieving a more favorable ratio, and as such can result in a different “settling point” over time. Gaining muscle mass has numerous benefits when it comes to supporting metabolism and can also lead to someone having a vastly different looking appearance within their same “settling point” range.
Lastly, the role that mindset plays in whether or not someone is capable of achieving a new “set point” for themselves cannot be emphasized enough! Belief is at the root of action-taking: if someone believes in a future self that adopts behavior changes that can test the supposed “limits” of genetics and biology, then they are much more likely to take action towards sustainable, permanent change. If someone is committed to the belief that they are incapable of influencing the controllable aspects of weight/body fat change and that biology rises above, then naturally they will have a difficult time changing no matter what the science says about body weight set point theory. Bodily autonomy holds an incredible amount of power in this conversation.
The Takeaway: Can You Change Your Body's Set Point?
Body weight set point theory, at its basis, explains how and why weight varies from person to person and validates many individual experiences around the challenges of achieving long term weight change. However, changing whatever set point we believe we may have is possible when we consider the other variables at hand and bring the right mindset and strategies to the table.
If you’re ready to challenge your own “set point” with sustainable nutrition, mindset work, and strategies that actually support long-term change, our coaching team is here to help. Reach out to learn more about how we can support your unique goals.