Mini Mikkipedia - explaining your body fat setpoint
Trancript dictated using AI transcription, errors may occur. please contact Mikki for clarification.
Hey everyone, it's Mikki here. You're listening to another Mini Mikkipedia on a Monday. And this Monday, I wanted to chat about body fat set point and body weight set point actually. So this was a topic of conversation that's come up a couple of times with a couple of guests, Dr. Stefan Guyenat, and I'm going to talk about his opinion, his view on it.
and also Dr. Ted Naiman. And I've had a couple of requests that have asked me to go in just a little bit more detail on it. So that is what I'm devoting this Mini Mikkipedia to today. And for those of you who are unfamiliar with the term or aren't really sure about it, the body fat set point theory, it's a well-recognized concept in metabolism. So it posits that...
Each individual has a natural body fat level that their body tends to gravitate towards and strives to keep stable. And this set point varies for everyone. For instance, if you're a man who weighs about 86 kilos and have maintained that weight and let's say a body fat percentage of around 16% for over 10 years, then it's likely that that's your body's preferred level. And
We all know people like this, that over the course of several years, if not decades, their body composition hasn't changed that much. It doesn't seem to vary depending on what they eat, how much training they do, that kind of thing. So it's very stable. And this set point is influenced by genetics, lifelong dietary habits, physical activity, and other personal experiences.
Also, there's obviously a hormonal element as well. And many people argue that the hormone leptin primarily regulates the set point. So leptin is a hormone that is released in response to eating. And when we eat and we are satisfied, leptin levels rise. And leptin is also primarily stored in our fat tissue. So people who have a low body fat level tend to have lower leptin levels. And
when we diet and lose body fat, our leptin levels do shift as well and they lower. People suggest, and Stefan Guirnet is one of them, that leptin is the primary hormone that regulates the body fat set point. Leptin reacts to shifts in the size of the adipocytes of the fat cells and this can be compared to a thermostat for our body's fat storage. Just as a thermostat
By activating heating or cooling systems when needed, leptin helps balance our body fat by responding to changes in the fat cell size. So it's not just the number of fat cells, it's the size of the fat cells. So the size of the individual fat cells indicate the body fat set point. When these cells begin to decrease in size due to a calorie deficit, there's a reduction in leptin secretion by the adipose tissue or fat tissue.
As a result, the metabolic rate drops, so this leads to fewer calories being burnt, and hunger increases, which prompts a higher calorie intake. This aims to revert the body back to its original set point by shifting the calorie balance positively. Conversely, during a calorie surplus, as fat cells grow, leptin secretion rises, as I said.
This leads to a heightened metabolic rate, reduced appetite, and a shift in calorie balance in the negative direction, guiding the body back to its set point. And I'll discuss that more in a minute. You know, when we diet, we do, as I just said, the number of calories it takes to maintain our new body weight is reduced. So part of it is just establishing that we actually need fewer calories than what we would have needed before we started our dieting phase.
86 kilos takes more calories in order to function compared to someone who weighs 76 kilos. In addition to that, we are far more insulin sensitive when we diet and reach a lower body weight. And this insulin sensitivity does make fat storage a bit more likely as well because insulin is a nutrient storage hormone. It's not just a carbohydrate or a glucose storage hormone. It also delivers fatty acids.
to fat tissue. So when we drop our body weight and we become more insulin sensitive, it does mean that depending on what we're doing with our diet, we're more likely to store body fat in that sort of initial state too. And then of course, many people can relate to the scenario where someone diets intensively for several weeks to shed say five or 10 kilos for a vacation, but binges during the holiday, regains the lost weight in no time.
or they come back from holiday and it doesn't take very long for them to revert back to their previous body weight. And many people who have managed to lose a substantial amount of weight, so more than 5% of their total body weight, which might not seem like a lot, but in the literature that's what's established. If you can lose 5% of your body weight and maintain that, that's actually very good from a health perspective.
While the initial weight loss seems quite straightforward, it does become progressively challenging, not only to lose additional weight, but even to maintain the lost weight. We see this time and again. This is accompanied by increased hunger payings, making further weight reduction and maintenance even tougher. And the natural default in this instance is to diet harder and exercise more.
to do more of the things which initiated that weight change in the first instance, but that doesn't necessarily result in sort of progressing forward with your weight loss goal at that time. And there is truth behind it as well, because after being in a constant calorie deficit with the fat cells decreasing in size and diminished leptin levels, the body's metabolic rate slows, hunger intensifies.
Furthermore, the efficiency of those fat cells in absorbing and storing nutrients improves, as I was talking about with that insulin sensitivity. So this enhanced efficiency means that when you indulge in high calorie intake, your body is primed to retain and store it as fat. So it does push you back towards that set point. And it is also true that every time you diet, meaning you consume fewer calories than your body uses, you're essentially triggering this body's protective mechanism.
The more frequently you engage in such diets, the more robustly your body fortifies this self-preservation mechanism, and observational data suggests that individuals who frequently go on diets throughout their lives tend to gain more body fat in the long run instead of shedding it. And there is really good research to show this actually. There's a national registry for weight loss diets in the states.
and it shows that over the course of sort of five years, it follows people who diet and people who don't. In fact, the people who don't diet tend to gain less weight than the people who diet, which is super interesting. It doesn't imply, it doesn't mean that dieting directly causes weight gain, because of course, if you're in a calorie deficit, you're not gonna be gaining weight. This would contradict basic principles of weight loss, if you like, or physics or whatever.
But the issue arises when the individuals continually diet but intersperse these periods with rapid weight regains, which is often faster than the weight that has initially been lost. The cycle repeatedly activates the body's defense mechanism. Consequently, when the dieting phase concludes and the person reverts to regular or excessive calorie intake, they not only regain the previously lost fat, but often add even more.
The cycle is the body's strategy to guard against potential future food storages. Moreover, individuals who habitually engage in this kind of fluctuating weight loss and gain, yo-yo dieting, over extended periods reinforce the defense mechanism each time they do so. So the key takeaway really is that weight loss should be sustainable. If you're constantly fluctuating between losing weight and gaining weight, you are
putting your body back into this defense mechanism where it's trying to hold on to whatever weight it gains to get you back to that set point with which it is comfortable at. And quick fixes like detox diets, juice cleansers, or short term fasting might not be long term solutions. So true success in weight management does lie in the ability to maintain weight loss over time. So therefore any dietary approach that isn't sustainable
should really be dismissed as a lasting solution. However, you know, the way that the body fat set point is posited is that there's nothing that you can do and that if you're at a particular weight, if you lose weight, then your body's just gonna fight really hard to get back to where that body fat set point is. But that's not true because of course, we all know people who have successfully managed to lose weight and keep it off.
but there are just better ways to do it than the super quick fix fad diets. And some of the solutions might be that you diet for a certain period of time, and then you hold your new body weight and you hold your diet at this particular point for, I don't know, two weeks, four weeks, six weeks, eight weeks, and then you go on another sort of dieting phase. So certainly you cut, you maintain,
and then you cut again. People often look to reverse dieting as a way to sort of be able to hold the body weight that you've achieved with dieting, yet slowly eat more calories, like this is part of it as well, so your body gets used to sort of existing on higher calories at a lower given body weight. But that doesn't necessarily work that way either with sort of reverse dieting. And I talked to Eric Helms,
a little bit about reverse dieting and I'm going to be speaking to another person who really works in this space about how reverse dieting really works. But that's not necessarily going to help you establish this new body fat sort of set point or body weight set point. And part of it is just time. It's allowing your body time at that body weight and losing weight slowly is one of the best things that you could probably do.
to help establish that new body fat set point. Also, it's about what your brain is registering to. And this is what Dr. Stefan Guernay talks about. He's a neurobiologist. I've had him on the podcast before. And we talked about his research in obesity. And he's written extensively on the body fat set point theory. And he talks about the lipostat. And he believes in the idea that the brain plays that central role in determining and defending our body weight and that it exists.
and that each person has a set point or a range where their body naturally wants its weight to be. And the brain works to defend this range. If you lose weight, hunger increases and energy expenditure decreases to push you back to your set point. And the reverse happens if you gain weight. And of course we know that to be true when you lose weight. You do feel a bit hungrier, your non-exercise activity thermogenesis decreases so you do burn less calories. And this is a prime.
situation for you to regain back the weight that you've lost. And this is regulated by the brain. So the hypothalamus, a region in the brain, receives signals from the body, notably leptin as I discussed, and when leptin levels fall as our fat stores decrease, this makes the brain implement mechanisms to regain the fat, and they rise when fat stores increase, leading the brain to suppress hunger and increase energy expenditure again. However,
You know, one of Guernay's major points is that our current environment with its highly palatable calorie dense foods might trick our brains into setting a higher set point than what is truly a natural set point actually. So in essence, certain foods can make our brains think we should have more fat than is healthy, which is super interesting. And you know, this really does speak to just how much our environment influences our brain and our behavior.
And so therefore it's not necessarily that your body fat set point, if you're in a larger body and have been that way for some time, it doesn't mean that that's where your body wants to be. It's the environment and the foods that you eat can trigger your brain to believe that. So therefore changing what you eat can help you change that body fat set point down to a healthier, more natural place where you would otherwise be. So it might seem like your set point is robust, but Gine does believe
that it's not entirely fixed. Lifestyle factors, including diet, sleep, stress, and physical activity can influence our set point. And whilst it's not easy to alter one set point, understanding the underlying mechanisms can help guide effective interventions. And it is more than just leptin. And whilst leptin plays a crucial role in regulating appetite and body weight, Gine does
gut hormones and neural circuits also play significant roles in determining our set point and body weight regulations. And another thing which I think is worth mentioning is the body not only defends against weight loss but it can defend against excessive weight gain. So when we do gain weight or we're eating in a calorie surplus our hunger decreases so the body will naturally feel less inclined to eat.
even if this is quite subtle. Our energy expenditure might increase, so as someone gains weight, their metabolic rate can increase, both because they have more mass, but because their body is trying to expend more energy and offload those calories and counteract that weight gain. And also leptin levels rise, which signals to the brain that body fat stores are ample, and this theoretically would decrease hunger and increase energy expenditure in itself. But there are some caveats.
And again, it goes back to that environment. So the modern environment with the ubiquity of those palatable foods can trick the brain into setting a higher set point over time. But there's also something called leptin resistance. Just as in insulin in type two diabetes, it's believed that the brain can become resistant to the effects of leptin, especially when its levels are chronically high. And so when this happens, even with plenty of leptin circulating,
brain perceives a state of leptin deficiency and thus believes the body needs more fat stores. This can drive hunger and decrease energy expenditure even when somebody is already overweight or has obesity. So you can see that the idea of a body fat set point can feel maybe a little demoralizing for someone who is grappling with maintaining weight loss. And so a few practical things outside of
that idea of sort of blocking weight loss, particularly if you've got a lot of weight to lose by having periods of cutting and then holding your weight at a particular point, even if it isn't your long-term weight loss goal, but then cutting again, like that could be one way to allow your body to adjust to different inputs and different sort of energy expenditures or a different energy expenditure. Something else to consider as well is just that
If everything is happening from the brain, and this is a defense mechanism that your brain has sort of put into place, then instead of ramping up those behaviors that allowed you to lose weight initially, which often happens if we had a weight loss plateau or we're scared to gain weight again, so we're just gonna diet a little bit harder and exercise a little bit more, these are stress responses. And when we're hungry and when leptin levels are low, it's only going to exacerbate that stress.
and get your body into that self-defense mechanism. So instead, I think, you know, setting yourself up so you are increasing your energy expenditure, but not through hard out workouts and just walking. You know, just there's a lot to be said for getting back into the mode of protecting the brain, reducing that vital flight, and getting back into that rest and digest type mode, that parasympathetic state.
This is going to help your body become comfortable where it's at. So instead of doing more HIIT-based classes to burn more calories to ensure against weight loss, ensuring that your non-exercise activity is maintained once you reach a lower body fat percentage or body weight, this is one of the critical elements to sustainable fat loss actually. And we know if we look at research that people who successfully maintain weight are actually really active.
up to about 90 minutes a day. This doesn't mean that they're on a spin bike for 90 minutes a day, but they're moving. And that is going to help protect that energy expenditure that has reduced with the lowered body weight. Also, of course, with regards to what Gene talks about with the environment sort of working against us, ensuring we've got things set up in our environment to help with that sustainable fat loss approach. So we are not surrounded by palatable foods.
We are filling our plates with the things we know we need to be eating in order to maintain weight loss. Protein, fiber, things like that. We are reducing stress in other areas so the brain feels protected and safe. Because it does all come down to threat, right? So we are getting enough sleep, we are managing our stress. All of these things are really important. So if you just go on a diet and lose 8 kilos,
just by dieting alone or just by diet and exercise, then actually thinking about other areas of stress in your life can be super helpful to help ensure that you maintain that and allow your body almost this chance to catch up and realize that it doesn't have to go into this self-defense mechanism. So you can adjust the body fat set point. I think this we know. It is definitely something that exists. You know, it's well sort of established in science, but it's not a
deal breaker for most people. Those are just some of the thoughts from some of the sort of thought leaders in this space. Like if you've got any thoughts on it, I'd love to hear them. I'd love to hear your experiences or what you know of this topic. So please feel free to DM or let me know. You can catch me over on Facebook @mikkiwillidennutrition, over on Twitter, Instagram and threads @mikkiwilliden, or head to my website, mikkiwilliden.com and
Yes, send an inquiry through there. Alright guys, you have a great week. Talk soon.