You might have encountered set point theory while reading or discussing the limitations of weight loss or gain. Set point theory is a framework (or, more so, a collection of models) that explains why reaching or maintaining certain body weights can be difficult. It suggests that each person’s body tends to settle within a preferred range of body weight (even more specifically, body fat). While there’s a kernel of truth here, discussions around set points sometimes make it sound like we’re completely at the mercy of our biology, but that’s not quite right either.
In this article, we will break down what set point theories actually say, and how you might be able to work with (or around) them to support your goals.
Let’s dig in!
Understanding all the models and explanations behind “set point theory”
In the 1940s and 1950s, researchers were working off the lipostatic hypothesis suggesting that our fat stores regulate hunger and food intake. The idea was simple: If fat stores drop too low, they send signals to increase appetite, and the lower body fat gets, the stronger the hunger response. However, scientists weren’t sure what the signal was or how it was transmitted at the time.
In the 1990s, they discovered a signal link within the fat cell called leptin. Leptin is a hormone that (among many functions) plays a significant role in sending energy-stored signals to the brain. In particular, leptin reacts to lower body fat stores. The finding of leptin and the lipostatic hypothesis gave a lot of strength to the theory that we have ideal body fat levels and a skew toward a specific homeostasis. The line of thinking is if our body fat goes too low, our bodies send signals to increase our eating until we return to a predetermined fixed point of ideal homeostasis — our set point.
However, in testing for that, certain aspects of set point theory appeared too rigid. Rather than a single fixed point, there seemed to be a range in which body weight remains stable. The dual-intervention point model suggested that individuals have different signal strengths and comfort levels at both the lower and higher ends of body fat levels. The strength and pace of these signals determine how aggressively the body pushes back against weight change. The shorter the change, the less likely it will affect our weight in the long term. The more prolonged the change (like consistently eating in a calorie surplus), the more likely it can lead to a new state of normal at a higher (or lower) level of body weight.
And this is where we are currently in our models, which is sort of a combination of these models but without the rigidity.
Why do people care about set point theory?
Why does the average person want to know about set point theory? I think it boils down to two main questions:
- Is set point theory (or associated models) the reason that I can’t get to a lower or higher body weight?
- Is set point theory (or associated models) the reason that I can’t maintain the weight I’ve lost or gained?
What this comes down to is concerns about limitations when changing your body composition. We all have constraints (ranging from lifestyle to environment), but it’s a fair question to wonder how much of the challenge comes from metabolic factors outside our control. Is there an “invisible hand” guiding our diet decisions, or do we have more flexibility than we think?
To understand this, let’s examine what makes up our daily burn and how it can be affected by factors like unconscious activity, appetite, or environment.
A quick review of the key components of total daily energy expenditure
Our Caloric intake needs are based on our total daily energy expenditure (TDEE). Our total daily energy expenditure comes down to four main components.
Basal Metabolic Rate (BMR): Basal metabolic rate is the energy your body needs to maintain basic physiological functions at rest, such as breathing, circulation, and cell production. This typically accounts for about 60–70% of total energy expenditure for most people.
Thermic Effect of Feeding (TEF): The thermic effect of feeding refers to the energy your body uses to eat, digest, absorb, and store nutrients from food. This typically accounts for about 10% of total energy expenditure.
Exercise Activity Thermogenesis (EAT): Exercise activity thermogenesis is the energy expended during planned physical activities like running, weightlifting, or playing sports. This usually accounts for a relatively small percentage of total energy expenditure, but it can be a major factor for serious athletes.
Non-Exercise Activity Thermogenesis (NEAT): Non-exercise activity thermogenesis encompasses the energy spent on all physical activities that are not deliberate exercise, including everyday movements like walking, household chores, and even fidgeting. This is usually the second largest energy expenditure category, but its relative contribution is heavily influenced by occupation and lifestyle.
The impact of Calorie intake on physical activity
While I’ll talk more about BMR in a moment, I wanted to start with our conscious and unconscious activity. Because for many, daily adjustments in movement can play a more significant role than they might realize.
NEAT was first described by researcher James Levine, who has spent much time examining how we react to movement based on our feeding states. Generally speaking, NEAT is allocated to our unconscious activity (fidgeting, pacing, knee-knocking). However, some studies have included other purposeful activities such as walking or chores. You can also tie in research on spontaneous physical activity, but for now, we will use NEAT as our catch-all term.
How we eat can affect both deliberate and unconscious movements, such as how hard we train or whether we decide to go for a walk after dinner. During a Calorie deficit, you might find workouts feel harder or that you’re less likely to play with your pets or kids. Eating more food can have the opposite effect. You may find yourself more restless, doing extra yard work, or suddenly feeling motivated to start on that house project you’ve been putting off.
What makes NEAT such an interesting concept is that it doesn’t affect everyone the same or in the same way. This means that just because you eat more doesn’t mean you’ll want to move more. Some might still have energy bursts despite being deficient. What’s intriguing is that the response varies – sometimes significantly
Though it was a small study, Levine and colleagues found a range in how much people increased their activity levels in response to overfeeding. They studied 16 nonobese adults who consumed an estimated 1,000 Calories above their maintenance needs. The researchers monitored changes in daily activity and energy expenditure via doubly labeled water while ensuring consistent predetermined exercise. Changes in nonexercise activity thermogenesis ranged from a drop of 98 kcal/day to an increase of 692 kcal/day, with weight gain ranging from 1.4kg to 7.2kg. The graph below shows fat gain ranges.
Essentially, at any stage of surplus or deficit of calories, our bodies adapt. As discussed, there appears to be more of a range rather than one point of settling that we will always go back to. In studies looking at NEAT, “variability” is an accurate descriptor. A 2018 systematic review found that some people move less, some keep their activity steady, and others ramp up their non-exercise movement. From elite athletes to lean or obese overfeeding participants, everyone seems to respond a little differently regarding their unconscious activity expenditure.
We do not yet know what causes one person to respond differently from another. Conversations range from neuropeptides to genetics to environmental factors. Simply put, these tendencies exist on a spectrum for individuals and could change over the years depending on health or lifestyle.
Bringing this back to a conversation on set points, let’s consider an example where you have a hard time gaining weight. One limiting factor for you could be that even though you’ve done a good job at increasing food intake, you’ve also increased your physical activity, making it harder to add mass. Conversely, you could be an individual who dramatically slows down when you start restricting food. In both cases, making a conscious effort to adjust movement, either by scaling back extra activity or intentionally keeping it up, could help you get to your goal more easily.
Beyond movement and into metabolic shifts
So far, we’ve focused on how movement contributes to total daily energy expenditure, but physiological adaptations also play a role.
Looking at what makes up our TDEE, we can see decreases or increases in TEF from eating more or less food throughout the day. We generally observe that increasing protein and eating more whole foods while decreasing ultra-processed foods can increase TEF. In the simplest line of logic, if you’re eating less overall food, you will have a decrease in TEF. This is one reason why focusing on low energy density foods could give you an advantage, and it doesn’t seem that the increase in TEF causes an increase in appetite either. Additionally, absorption can change with increased food intake, influenced by the volume of food consumed and whether you’re lean or obese.
Most of the remaining changes vary in impact depending on whether you’re cutting Calories or eating in a surplus.
Adaptations to deficits
Adaptive thermogenesis is primarily driven by hormonal shifts in response to weight loss, with the biggest player being the leptin that we discussed earlier. Again, when you lose fat, leptin levels drop, which can downregulate energy expenditure and increase hunger. Thyroid hormones — especially T3 — also take a hit, slowing down metabolic processes. “Hunger hormones” such as ghrelin can also increase. While these things don’t make a person eat more food, collectively, it can drive you to slow down physically, to eat more, or to be less compliant with your goals.
That said, research in controlled settings shows that weight loss is not inherently limited when caloric intake is sufficiently restricted and managed. The Minnesota Starvation Study is a well-known example that pushed the boundaries of not only restrictive diets but also the safety of these diets. We can push past a perceived lower boundary, but it is not easy, does not always feel good, and becomes significantly harder in free-living environments.
As to how our BMR is affected, once we move into an actual reduction in tissue, this leads to more permanent (but expected) and reasonable decreases in BMR. Greg Nuckols did an excellent write-up on how weight loss affects BMR here if you want to read more on this topic.
Adaptations to overfeeding
Greg also covered similar details in this article regarding weight gain and basal metabolic rate. Weight gain influences our metabolic rate, but not in the same way weight loss does. With an energy surplus, BMR initially increases like a short-term metabolic “boost,” but over time, it settles proportional to the tissue gained.
Depending on how long the overfeeding lasts, we may establish a new normal, and this process is likely a little easier than with weight loss. In a study that examined overfeeding in people who were normal weight with no noted eating disorders, participants first spent 14 days eating ad libitum while ensuring adequate nutrition to establish a baseline. They then entered a controlled 13-day overfeeding phase, consuming 135% of their baseline intake, followed by a return to unrestricted eating. On average, participants gained 2.3kg. After overfeeding stopped, they ate less than during the surplus phase but did not compensate by eating at a deficit or losing the gained weight immediately.
And as a reminder, it’s the lack of trying to return to the previous bodyweight level that plays a role in debunking the more rigid aspects of set point theory. For example, a systematic review found that people tend to gain weight during the holiday season. In this instance, the holiday season is defined as the last week of November through the first or second week of January. However, people don’t typically lose all of the weight they gain throughout the rest of the year. Therefore, if body weight was so tightly regulated as posited in the set point theory, we’d expect a stronger push toward weight loss after that seasonal gain, but that’s not what happens.
From a feedback control perspective, this aligns with the dual-intervention point model discussed earlier, where body weight isn’t defended at a single set point but rather shaped by repeated exposures and the strength of environmental signals. In this instance, the holiday season is long enough to reinforce a new baseline weight rather than just being an isolated fluctuation. Over time, this pattern can lead to gradual weight gain, with some individuals entering each new holiday season slightly heavier than the last.
Ultimately, it can be hard to gauge what signals are driving the desire to eat or not eat, as factors like hunger and appetite can interplay with hedonic desire. But these adaptations to eating are real and affect our ability to stick to particular diets or body weights.
Environment’s impact
As discussed in other articles, our environment can greatly influence our daily lives. Our physical surroundings, work, and lifestyle contribute significantly to daily Calorie burn, allowing for an easy or more difficult path to our weight goals. By shaping our environment, we can support habits and make progress toward our goals. On the other hand, certain changes in our environment can create challenges we might not anticipate. For example, a study in China looked at the changes in weight gain relative to obtaining a motorized vehicle. The study followed adults over eight years and found that men who acquired a motorized vehicle had twice the odds of becoming obese compared with those without a motorized vehicle. This association persisted even after controlling for diet, income, and physical activity.
This has also been studied in many societies and cultures, ranging from an Amish community to commuters in the UK. In short, how we move through our day can shape our bodies as much as purposeful exercise.
Lastly, consider your actual desire and comfortability at different body fat and muscle levels. Each person, for varied reasons, has their own lower and upper-end body weight levels, which can also change throughout one’s life. Understanding your motivations and drive behind your goals can also be a factor in your ease and, by proxy, feelings of resistance to the process of altering your body composition.
Is set point theory (or associated models) why I can’t keep the weight I’ve lost or gained?
Now that we understand the factors that contribute to our ease (or lack of ease) in achieving certain body weight goals, let’s discuss the long-term success of maintaining what we’ve worked to achieve in a little more detail.
As you can see, most of the factors that apply to your process of losing or gaining weight apply to maintaining your results. At the high or low ends, you will still face all the same issues with hunger, unconscious or conscious energy expenditure, and environmental impacts. Beyond getting to the essential body fat levels for general hormone function (those levels differ for men and women), you will be dealing with various difficulties (or ease) depending on these factors.
A systematic review examined 33 studies with 2,528 participants to determine whether adaptive thermogenesis occurs after weight loss in adults. It also examined a wide variety of participants, ranging from diet restriction to bariatric surgeries, and found that while adaptive thermogenesis did exist, it seemed to fade after a period of weight stability.
The National Weight Control Registry tracks individuals who have successfully lost weight and kept it off long term. But maintaining a lean, healthy body weight is different from pushing body fat to extreme levels. A casual dieter aiming for sustainable weight loss faces different challenges than a bodybuilding competitor trying to reach stage-ready leanness. For a stage competitor, extreme leanness isn’t meant to be permanent. After a competition, refeeding is necessary to return to a stable body weight. How much body fat needs to be regained depends on the individual, but it’s important to note that stage-level conditioning often includes water manipulation, making competition weight even less sustainable.
In general, an ideal long-term body fat level is one that supports hormonal balance and a maintainable nutrition and training lifestyle. Some might argue that this suggests a more rigid set point, but in reality, it’s more about balancing sustainability and health rather than being locked into a single number.
So, can you maintain lost weight?
Plenty of factors, both physiological and behavioral, make it easier or harder to permanently adjust our weight. The speed, aggressiveness, and duration of your dieting efforts influence how strongly your body pushes back. That said, while physiological resistance to weight change is real, we also tend to resist change in general.
So, I’d argue that within reasonable body weight ranges, most goals are achievable with the right strategy and an informed approach, and therefore, a “fixed point” is probably not to blame.
Ultimately, weight regulation isn’t just about physiological resistance, but also our environmental and behavioral patterns that can reinforce certain “stopping” points. But if those external influences are adjusted and intake is controlled, we could push much further than we might think and not only make our body weight changes but keep them.
Decreasing unnecessary adaptations or difficulties
There are things we can do to make things harder or easier on ourselves, depending on the goal. Here are a few tips that might help along the way.
Lose or gain at the appropriate pace. Regarding weight loss, while you can’t stop a degree of metabolic adaptation, you can minimize some of its severity and effects on you. The best way to do this is to lose more gradually while maintaining a solid protein intake and partaking in resistance training to preserve muscle mass. For gaining weight, since this is typically going to be allocated toward muscle mass (which is a somewhat different topic), I highly recommend checking out this article on rates of weight gain for bulking.
Keep good data. With good data, you have a much better chance of identifying patterns and determining the best next steps to take. Ultimately, it’s hard to make adjustments if you’re not tracking. For example, If you’re struggling to lose weight but only log your intake sporadically, you won’t know whether you’re overshooting your calories, underestimating portion sizes, or just need to adjust your rate of progress. Using a food journal or tracking app isn’t about micromanaging every detail forever, but about getting enough reliable data to make informed decisions.
Look at your environment. Many moving parts influence body composition, and those factors shift over time — job changes, moving, evolving training knowledge, having kids, and more. So, it’s worth considering how your current environment and lifestyle shape your progress. Meaning, does your environment contribute to low activity, making fat loss difficult without resorting to very low Calories? Or, are you so active that eating enough to gain weight feels like a challenge? There’s so much we can’t control, so analyze where you can make a shift.
Understand the goal. It might sound simple, but we don’t always step back and assess why we’re doing what we’re doing. Instead, we fall into routines without considering whether our approach actually makes sense for our goals. Have you looked at training intensity if you’re struggling with hunger while trying to lose fat? Are you eating more low energy density foods? Have your energy levels dropped?
Before making drastic changes, take a step back and make sure your approach aligns with your goals. It’s common for people to jump into a pre-made program that’s just the wrong strategy or fit for their goals or lifestyle.
TL;DR
- Your body isn’t locked or fixed to a specific weight. Instead, weight regulation happens within a flexible range and can adjust to new normals in either direction (within essential body fat levels).
- Metabolic adaptation is real, but its severity varies depending on the person, the direction of weight change, the rate of change, and how far weight moves from its usual range.
- Resistance to weight change often comes from shifts in activity levels and appetite. In some cases, adjusting nutrition or physical activity strategies can help manage these effects.
- Weight changes are possible but usually require more strategy and conscious effort than most people realize. Education and tracking can help smooth the process and reduce friction.
