Have you ever wondered why it’s so hard to drop below a specific number on the scale, even if that weight isn’t particularly low for your height? If so, set point theory may have the answer.
Many people easily gain and lose within a small range of weights, but find it nearly impossible to move the scale when they decide to drop below a certain number. Although maybe not as obvious, the same phenomenon occurs when they begin to gain weight (intentionally or not) outside of this range. As a result, most people stay at around the same weight for all of their adult lives, regardless of lifestyle changes. In the early 1980s medical professionals started describing this phenomenon as “set point theory”.
Here we’ll explain set point theory, the science behind it and current experts’ opinions of this concept!
Table of Contents
What is the Set Point Theory?
Set point theory is the idea that each person’s body has a specific weight or fat percentage that it biologically defends. That weight or body composition is your “set point”. So, physical mechanisms like hunger and metabolism will, at least to some degree, override any conscious effort to stray outside of that set range.
The result is increased hunger, slowed metabolism and even emotional changes (like depression) when your weight drops below a pre-determined set point. Conversely, if you start accumulating extra weight or fat above that set point, your metabolism will rev and hunger will decrease in an attempt to bring your weight back down.
Unfortunately, weight regulation is naturally asymmetrical. Biological cues to maintain weight (and body fat) are much stronger in response to weight loss as compared to weight gain. This is why, ultimately, it’s a lot easier to gain weight than it is to lose it.
What Determines Your Set Point?
Each person has a different set point. No one knows exactly how this point is set, but it is likely a combination of both genetic and environmental factors. Each person has a unique set point, even if other factors like height or shoe size prove equal. Set point theory, then, is a strong argument against doctors’ ubiquitous height-weight (or BMI) charts acting as the ‘end-all, be-all’ in determining healthy body weight.
It’s undeniable that set point varies person-to-person, but what determines each person’s set point or range? Some doctors claim that set point, like height, is almost-entirely genetic. Studies that show obesity runs in families, and may have some heritable component, support this hypothesis.
Others argue that set point must be at least partially environmental. The latter group points to research demonstrating that children of mothers who’ve undergone weight loss surgery are significantly less likely to develop obesity than those whose mothers never underwent surgery and remained obese. Since both groups of mothers were naturally prone to obesity, this second body of research indicates that weight control is – at least partially – environmental. Environmental factors that affect set point would be things like lifelong diet and exercise habits.
Hormones also impact set point, but you don’t have much control over these chemicals. Still, high testosterone levels will usually push set point down. Similarly, older women often experience an increase in their set point due to post-menopausal hormonal changes.
How Does Your Body Defend Its Set Point?
Regardless of what determines an individual’s set point, most experts agree that there is about a 10-20 pound (or 4-9 kilogram) range that your body likes to exist in. Try to go outside this range and your body will push back. For most people, this point remains constant for the entirety of their adult lives unless major stressors (like famine, disease or menopause) step in to alter your body’s “normal”. Some dieters also successfully adjust their body’s set point over time despite the body’s resistance to change.
So, how does your body defend this pre-determined set point?
The main line of defense is leptin. Leptin is the main hunger-regulating hormone in our bodies. It works together with another hormone, ghrelin, to send signals from the body to the brain about when we’re hungry or full. Leptin is produced primarily in fat cells, so people with more fat tend to have more circulating leptin. Conversely, those who are consuming too few calories or burning through their fat stores too quickly experience lower levels of circulating leptin. In response to low leptin levels, appetite increases and resting metabolism slows. If you’re constantly hungry, most of us will start eating more –consciously or not. This is the body’s way of ensuring you don’t drop too far below its comfortable set point.
The same process activates to discourage weight gain above an individual’s set point, but unfortunately it’s not as strong. Our weight regulation mechanisms are much stronger to prevent weight loss than they are for weight gain. This likely has evolutionary roots in allowing for better survival prospects in harsh or unforgiving environments. However, when we couple this natural imbalance with a Western diet, the body’s mechanisms do little to dissuade weight gain. Studies show that modern diets high in fat and sugar promote “passive eating”, which is essential eating without regard to your body’s hunger cues. If the food we eat further promotes ignoring the already-weaker cues from our bodies, there is little biological help in terms of preventing weight gain above one’s set point.
How to Change Your Set Point
Now you’ve learned a little more about set point theory and how our bodies establish a set point. Still, if you’re looking for how to lose weight, chances are that you’re hoping there’s a way to adjust this range. Good news: science indicates that yes, it is possible to modify your set point with weight loss! The catch is that it won’t happen immediately – shifting your set point takes time and consistent work.
To change your set point, you need to:
- Lower your body weight/body fat to the lower end of your set point.
- Give your body time to adjust to the new “normal”.
- Maintain, or continue lose in a healthy and moderate way.
Let’s talk a little more about each of those.
1. Lower Body Weight/Fat
The first step in lowering your set point is the initial weight loss. As with any other lifestyle change, slow and steady wins the race. Adjust your intake and/or activity so that you are in negative energy balance and the weight will slowly, but consistently, come off. This means eating less or exercising more so that you burn more calories than you consume each day. To achieve a loss of one pound per week you should average a daily energy deficit of about 500 calories. If your goal is -1.5 pounds per week, boost this imbalance to 750 calories per day.
After a few weeks or months of following this same plan, your body will naturally plateau. That’s your cue to move onto step two.
2. Let Your Body Adjust
Some set point theory experts have even started referring to set points as “settling points” instead. This is because your body “settles” (or becomes comfortable) at a certain weight, but this range is ultimately modifiable. The trick is: you need to let your body adapt, or “settle”, to a new weight after major weight loss.
Just after losing 15, 20, 30 pounds or more, your body remains eager to regain that former weight (and fat). This is part of the reason the rate of weight re-gain after dieting still hovers at around 80%. Still, that doesn’t mean it’s impossible to keep the weight off. One of the things successful maintainers do is that they lose slowly and accept plateaus as part of the weight loss process. These halts in weight loss are critical for your body to “settle” at a new, lower weight and stop fighting to push you back up to the previous, higher weight.
3. Maintain or Keep Losing
If, after maintaining your weight for several weeks or months, you still want to lose weight, then that that is the time to start your weight loss process again. If you are happy with your current, lower weight – congratulations! Now is the time to stay conscientious and work to maintain that new, more slender figure. As your body “settles” at this new set point it will stop thinking that you’re starving and hunger should ease. If you are truly in-tune with your body’s cues, it will become much easier to maintain this lower weight as the body stops trying to defend that old weight and learns that this lower weight is the new normal.
Weight Loss & Set Point Theory
In summary: it IS possible to modify your set point, but it won’t happen overnight.
If you are hoping for weight loss beyond your set point, check out the tips above to slowly and healthfully adjust your body’s set point. However, before going to all this effort, it may be worth evaluating if further weight loss will really prove necessary, or even beneficial. To start, check out our BMI calculator tool to determine whether you’re currently at a healthy weight. If you’re feeling stuck at your body’s set point, and you’re not overweight or obese, your body’s natural weight may be perfectly calibrated already! In that case, fixating on altering your set point and losing weight may be more harmful than helpful.
What do you think about set point theory? Share your thoughts and questions with us in the comments section below!