Is your metabolism holding you back from achieving your fitness goals? Do you ever wonder why your progress slows down despite your best efforts? Why do some people seem to burn more calories than others, even at rest?

Philip (@witsandweights) uncovers 7 surprising facts about your basal metabolic rate (BMR) that will completely change how you think about fat loss, energy, and fitness. You'll discover how factors like body composition, organ size, and even athletic habits play a huge role in your metabolism. From the truth about aging and its impact on BMR to debunking myths about metabolic adaptation, you'll learn practical insights to help you work with your body's natural processes and achieve better results. Whether you’ve been feeling stuck or frustrated, understanding your BMR might be the key to unlocking your fitness goals.

🎞️ To learn how to download and setup MacroFactor for free so you know your exact metabolism for any body composition goal, watch this video or go to https://youtu.be/HTOmVtR9UZw (don’t forget to use code WITSANDWEIGHTS to try it for free!)

Today, you’ll learn all about:

2:48 Fact 1: The wide range of normal BMRs
5:34 Fact 2: How organ size impacts BMR
7:22 Fact 3: Allometric scaling of metabolism
9:11 Fact 4: Athletes' secret metabolic advantage
13:11 Fact 5: How BMR changes with age
14:35 Fact 6: Metabolic adaptation during fat loss
18:07 Fact 7: BMR and PCOS misconceptions
21:20 Outro

Episode resources:

• The MacroFactor BMR Series

Related Episodes:

• Bigger Isn't Always Better for Strength or Metabolism (Scaling Laws) | Ep 195

• Carbs Aren't the Problem (Keto, Paleo, Bioenergetic, and Pro-Metabolic Diets) | Ep 224

Episode summary:

Understanding metabolism is crucial for anyone looking to lead a fit and active lifestyle. In this episode of Wits & Weights, host Philip Pape delves into the often misunderstood topic of metabolism, revealing surprising insights that can revolutionize your approach to fitness and fat loss. At the heart of the discussion is the basal metabolic rate (BMR), the energy your body requires just to stay alive. Contrary to popular belief, your metabolism is not solely determined by muscle mass and activity levels; it also heavily relies on the energy demands of vital organs such as the brain, liver, heart, and kidneys. These organs, despite constituting only a small percentage of body mass, account for a significant portion of your BMR.

One of the most common misconceptions addressed in the episode is the idea that metabolism inevitably slows down with age. While it's true that BMR can decrease over time, this decline is often attributed to loss of muscle mass and decreased physical activity rather than age itself. By maintaining muscle mass through consistent exercise, individuals can effectively counteract the age-related slowdown. Moreover, athletes demonstrate a fascinating connection between athleticism and metabolism. They often burn more calories at rest, thanks in part to larger organs like the heart, which support their increased physical demands. This insight highlights the importance of regular exercise and strength training in maintaining a high metabolic rate.

Another key point discussed is the phenomenon of metabolic adaptation during weight loss. As you reduce calorie intake, your body may conserve energy, making it seem as though your metabolism is slowing down. However, this adaptation is largely reversible once normal calorie intake resumes. Understanding this concept is crucial for setting realistic expectations during a calorie deficit and ensuring sustainable weight loss. The episode also explores the concept of allometric scaling, which describes how metabolic rates vary across different body sizes. Larger individuals have lower BMRs per unit of body mass compared to smaller individuals, emphasizing the need for personalized fitness and diet strategies.

Philip Pape provides practical guidance for kickstarting your fitness journey, beginning with the initial maintenance phase. By calculating your starting calories and macros, you can tailor a diet and fitness plan that aligns with your body's unique needs. This personalized approach is further supported by tools like the Macrofactor app, which uses actual nutrition and weight data to calculate true maintenance calories. The app offers personalized recommendations, taking the guesswork out of tracking your metabolism and making it easier to achieve your fitness goals.

Throughout the episode, the importance of understanding and working with your body's natural processes is emphasized. Rather than relying on generalized guidelines, listeners are encouraged to embrace the uniqueness of their own metabolism and make informed decisions that support their fitness journey. By leveraging the insights shared in this episode, you can transform your understanding of metabolism and achieve a healthier, more efficient lifestyle.

The podcast episode is a treasure trove of information, debunking myths and offering actionable tips for anyone seeking to optimize their metabolism. From the surprising facts about BMR to the empowering message that you can control much of your metabolic fate, the insights provided are both enlightening and motivating. Whether you're an athlete looking to enhance your performance or someone simply trying to navigate the complexities of metabolism and weight loss, this episode of Wits and Weights is a must-listen.

In summary, unlocking the secrets of your metabolism is not just about understanding calorie expenditure but also recognizing the role of your body's organs, muscle mass, and physical activity. By challenging misconceptions and embracing a personalized approach, you can harness the power of your metabolic powerhouse to support a fit and active lifestyle. With practical tips and resources at your disposal, you're well-equipped to embark on a successful fitness journey.

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Transcript

Philip Pape: 0:01

If you've ever felt like your metabolism is working against you, no matter what you do, or that you're destined to have a slow metabolism because of your age, genetics or hormones, this episode is for you. Today, I'm going to reveal 7 surprising facts about your basal metabolic rate, or BMR, that will completely change how you think about your metabolism and fat loss. When you understand these facts, you'll see that your metabolism isn't broken or mysterious. It's just a bit unique and, more importantly, you'll learn how to work with your body instead of against it. Understanding your BMR could mean less struggle with fitness and nutrition, because you'll be able to make informed decisions that align with your body's natural processes. So if you've been feeling frustrated with your progress, constantly trying new diets but not maintaining your results, or simply confused about what's going on with your metabolism, what I'm going to outline today will give you the clarity and understanding you're looking for. Welcome to Wits and Weights, the podcast that blends evidence and engineering to help you build smart, efficient systems to achieve your dream physique. I'm your host, philip Pape, and today we're diving deep into the world of your basal metabolic rate, or BMR, which is simply the energy your body burns just to keep you alive. It is part of your metabolism, but a big part of it. We're going to explore seven surprising facts about BMR that will change how you approach diet and fitness. From the range of normal BMRs what's considered normal to the truth about metabolic adaptation during weight or fat loss, we're going to uncover multiple facts about your metabolisms that you might not have been aware of to give you more confidence in what to do with your training and nutrition. Now I want to give a shout out to the team at Macrofactor for putting together the very in-depth series of 10 articles highlighting the latest research on this topic, which I borrowed from heavily for this episode, because they are among the best in the industry at examining metabolism science, and I've added a link to the article series in the show notes so you can go straight to the source. Speaking of Macrofactor, if you want to take the guesswork out of calculating your metabolism and tracking your calories and macros, I do highly recommend trying Macrofactor. It's the only food logging app that uses your actual nutrition and weight data over time to calculate your true maintenance calories not just an estimate, not just a calculator. It's based on your actual body's response, and then it makes personalized recommendations and you can try it for free for two weeks using my code wits and weights all one word wits and weights. Just click the link in the show notes or search for macro factor in your app store and again use my code wits and weights all one word.

Philip Pape: 2:50

All right, let's talk about the seven BMR facts that I wanted to pull out from those very in-depth articles, which are extremely detailed. They cover a lot of the science and background, and I wanted to pick just the things that really stuck out that I think confuse people or will clarify things for you. I learned a couple of interesting things in the process as well, which is always a lot of fun. The first fact is the wide range of what are considered normal BMRs. Actually, let me take a step back.

Philip Pape: 3:18

What is BMR? Basal metabolic rate is the energy or the calories that you burn every day just to keep yourself alive, and it represents usually roughly around two-thirds of all the calories you burn. The other calories you burn are from digestion and exercise and non-exercise, but we are focusing on the big piece of the pie called the BMR, which is usually what causes the confusion for people as to what is going on with my body. So let's start with a fact that might blow your mind maybe, and it's very surprising for a lot of people One in five people so that's 20% have a BMR below 1200 calories or above 2200 calories per day. Okay, so the range of what's considered normal is huge. It's much wider than most people realize, and that variation exists because of differences in body composition. That's a big one. We talk about it on this show all the time. With muscle mass, you take two people of the same weight, age, gender, height, and yet one burns a lot more calories than another. Sometimes it's simply a function of how much more muscle the other person has, but it's also due to differences in genetics and your overall health, and I'm just going to use that as a catch-all when it comes to lifestyle and all the things that could possibly affect your metabolism.

Philip Pape: 4:43

So this kind of one-size-fits-all approach to dieting, where you hear specific calorie targets or numbers that are generalized, even for similar body types, or even when you use a calculator online, that is fundamentally flawed. Even though we love to have targets and we love to have ranges, it's so wide it's almost useless when you just look at it. That way, your friend might be able to eat 2,000 calories a day and maintain their weight, while you might need to eat 1,600 or, on the other end, 2,400 to do the same, even if you're roughly the same size and everything else. And people are frustrated by this. They're like, well, why does so-and-so get to eat way more than I do? And if you understand that this variation exists in the first place, it means that you have to find what works for your unique body, right, not just following general guidelines or comparing yourself to others. So that's the first big one of how wide that ranges.

Philip Pape: 5:37

The second fact today is how your internal organs impact BMR. And here's another thing that might surprise you your high metabolic rate organs so that's your brain, liver, heart and kidneys account for over 50% of your BMR, but they only make up 5% of your body mass. That's incredible. They are very hungry. These organs are like the leads of your metabolic band, the lead singers in your metabolic band. You know they are screaming out and taking up all the attention and energy and asking for calories all day long. Okay, they just, they just don't stop.

Philip Pape: 6:19

And what's even more interesting is that small variations in that organ size between people can significantly affect your BMR. So, for example, two people weigh 165 pounds, right, and they both have 130 pounds of fat-free mass, but one of them has organs that are 20% larger than average and the other person has organs that are 20% smaller than average. Their BMRs could differ by about 230 calories per day, and that is a bigger difference than you'd see from gaining or losing over 20 pounds of muscle. So this highlights why BMR can vary so much between individuals, even when they have a similar size and body composition. So it really isn't just about muscle mass, even though we often oversimplify it to that. It is not. It also explains why the standard BMR prediction equations you find online can sometimes be off by quite a bit because of organ differences. Crazy, right. So that's the second fact to be aware of, and it's not much you could do about that, and that's okay, it's just awareness.

Philip Pape: 7:27

Number three, something called the allometric scaling of metabolism. Now you might think, okay, as people get bigger, their metabolic rate just increases proportionally or linearly. That's not quite how it works. In fact, I've talked about this a little bit on my scaling laws episode a while back. You can go to my podcast and search scaling laws. If you're not sure how to do that, reach out. Anyway, it doesn't increase linearly or proportionally just because you're bigger.

Philip Pape: 7:55

In reality, larger people have lower BMRs per pound or per kilogram than smaller people, and this is due to a principle called allometric scaling A-L-L-O metric allometric scaling, and allometric scaling describes how characteristics scale across organisms of different sizes. As organisms get larger, they tend to slow down. In relative terms, an elephant obviously has a higher BMR than a mouse, but per unit of body mass, the elephant's BMR is much, much lower. And this applies to us too, as humans. Right, the very largest human adults are more than five times larger than the very smallest human adults. So, just literally, body mass. This means that the linear equations, like the ones often used to estimate BMR, tend to overestimate BMR for particularly small people and underestimate it for very large people, and so if you understand this, it can help you set up more realistic expectations, right? A lot of times it comes down to just not expecting more than you can for your own size when it comes to your metabolic rate. So that's. Number three is that allometric scaling, understanding that so if you're very large or very small, this could affect you BMR.

Philip Pape: 9:12

Fact number four athletes.

Philip Pape: 9:14

Okay, athletes have what appears to be a secret metabolic advantage.

Philip Pape: 9:19

And what I would say is that if you think, okay, I'm not an athlete, tell me about athletes, but I'm not an athlete.

Philip Pape: 9:24

I want you to question that premise before I go on, because you can become an athlete, and I don't mean you compete in a sport or get paid professionally, I mean you train, you lift weights, you act like an athlete, you live like an athlete. In fact, that's something I encourage everyone to do on the show, it's something I strive to do, it's something anyone of any age, any gender, no matter where you are, no matter your injury history, can do. So just keep that in your head and this might motivate you then to get back to the gym, to go train, to step it up, to do what you maybe haven't been doing, and that's because athletes have higher BMRs than non-athletes, even when accounting for differences in body composition. So again, kind of like the Oregon fact, where it was above and beyond body composition differences, athletes also seem to have higher BMRs. And again, we're not talking about people born as an athlete, we're talking about people who act as athletes, something anyone can do.

Jenny: 10:16

Hi, my name is Jenny and I just wanted to say a big thank you to Philip Pape of Wits and Weights for the 15-minute rapid nutrition assessment he offers for free. During that session, I found he asked really good personal questions that helped him be able to give me excellent advice and tangible tools which I've applied, and since then I have lost 12 pounds where I was otherwise stuck. Now that I'm closer to my weight goals, I'm focusing more on my fitness and muscle and strength. So I just really want to say thanks, philip, for all of your encouragement and the free tools you offer, as well as the positive podcast message. It's really helped me.

Philip Pape: 11:00

So two people can have the same amount of muscle and fat, but if one is an athlete, they're likely to burn more calories at rest. And this is probably due to a few factors. First, athletes guess what tend to have larger organs, particularly the heart, to support their increased physical demand. So I was wrong earlier in the episode when I said you can't do anything about your organs, forgetting about the heart, because the more healthy you are, the bigger your heart is, therefore the more calories you can burn just from that. And I've always wondered why is it that people who train and build muscle seem to burn way more calories than you would expect, even for themselves, just from the muscle mass? Like if you just took muscle mass, you know roughly at most nine calories per extra pound of muscle mass per day. It's not much at all, and yet they burn way more than that. Is it just that they're burning more calories in general, or is it some of these other factors, like a bigger heart, because they're more healthy? Second, regular intense exercise itself, the training itself, movement training, lifting weights, sprinting, cardio, doesn't matter can lead to lasting metabolic adaptations. Okay, your body adapts to these things. You're doing that increase energy expenditure even when you rest and again, I'm not just talking about muscle mass You've become a person who your body expects to be athletic and to be moving and it craves all that energy all the time. So your energy expenditure is simply higher, even when you're resting. And then the really interesting part if that wasn't interesting already is, as I alluded to before, you don't have to be a professional athlete to see these benefits. Even recreational exercisers, trainers, you know, people who just occasionally, more than the average population, are active, tend to have higher BMRs than completely sedentary people. So if you're looking to boost your metabolism regular movement, regular exercise, especially strength training, because it combines a lot of these into one, one of the best things you can do it's not about burning calories to lose weight. It's really about increasing your energy flux and being a person who just needs and wants and craves that energy to be a thriving and active individual, which is a much more positive way to look at it in the relationship and context to food and protein and carbs and all the things BMR.

Philip Pape: 13:14

Fact number five and this is how BMR actually changes with age. You've probably heard that your metabolism slows down as you age, especially after 40, right, that's the big line. The truth, as always, is a bit more nuanced, because BMR does decrease with age, but it's very gradual through most of our adulthood. How gradual? Well, research shows that BMR decreases by about 1-2% per decade from your 20s to your 60s. So that's like 20 to 40 calories per decade, which is not exactly your metabolism dropping off a cliff, like many people are fearing. Now. This rate of decline does approximately double or triple beyond age 60. But even then, it's not as dramatic as it's often portrayed, because much of this decline is due to something you can control. It's due to the loss of muscle mass and decreased physical activity, not aging itself, and that's empowering. That means you have control over it. That's such a positive message. This means that by maintaining muscle mass through strength training and staying active, you can largely offset the age-related decline in your BMR. So if you're in your 40s or 50s or beyond and you're worried about your slowing metabolism, take heart, because your BMR likely hasn't changed as much as you think and you have a lot of control over keeping it high. All right, bmr.

Philip Pape: 14:38

Fact number six let's talk about metabolic adaptation. Okay, this is your body's protection mechanism, right? If you've ever been on a diet, if you've ever been in a calorie deficit of any level, you might notice that your loss in body mass, your weight loss, slows down over time. You tend to start to hit plateaus, or it gets harder even if you keep eating the same amount, and this is due to a phenomenon called metabolic adaptation, which we do talk about it a lot, but if you're new to the concept, it's simple During weight loss I should say more clearly, during a calorie deficit, which will induce weight loss, if you're truly in a calorie deficit though some people can be in a very slight calorie deficit and the weight loss is so slow it's unnoticeable.

Philip Pape: 15:20

During this calorie deficit or weight loss, your BMR decreases more than would be predicted based on changes in, say, body composition alone or even the weight loss itself and the adaptation. For most people it averages around 5% to 10%, and it's your body's way of conserving energy. Right, it's your body's way of conserving energy when it senses a shortage in resources coming in, and we know that this is temporary, it is largely temporary. It is caused by hormones such as thyroid. We've seen, we know studies that have compared, that have looked at thyroid production. You know TSH, t3, t4, and we see this almost immediate drop 5% or so, 6% I think was the average from the study and it kind of stays there at that level.

Philip Pape: 15:59

It's not like it keeps dropping while you continue to be in the deficit. Now maybe if you ramped up the deficit it would drop more. But let's say you're in a 500 calorie deficit and it drops by 5%. It's going to stay there for the next, say, 16 weeks of your fat loss phase and then once you return to maintenance calories and your weight stabilizes right, most of the metabolic adaptation reverses. You know, some studies do suggest that a very small amount let's say sub 5%, 3 to 5% might persist long-term after significant weight loss, might persist long-term after significant weight loss, but it's much less dramatic than many people fear and it's probably just the piece that's due to you weighing less. In other words, it's not really metabolic adaptation, it's just I mean it is, but it isn't right. It's you weigh less, your body just doesn't need to burn as many calories carrying around less weight. But the adaptation from hormones that was more dramatic during fat loss, that recovers and so if you understand metabolic adaptation, then again you can have realistic expectations.

Philip Pape: 16:56

During a dieting or a calorie deficit phase it's normal for the rate of loss to slow down over time unless you are tracking and aware of it and then adjusting your calorie intake to continue making progress. That's the key. We need to maintain the calorie deficit, not the calorie intake, right? Because if you just calculate your number at the beginning and you're at one calorie level and you eat 500 calories less than that, you might start losing weight at the beginning, but then it slows down because the actual calories you need are less due to this process. So you need to eat even less or do something else that bumps your metabolism up. So this doesn't mean your metabolism is broken or that you can't continue to lose more fat. I mean you can lose an incredible amount of fat if you are aware, if you're tracking and you're managing your lifestyle properly.

Philip Pape: 17:43

I help clients do it all the time. I can help you do it. If you want to reach out and you're like I don't buy it or I'm not sure, or my metabolism is so unique, I don't think this is going to work for me, it will, it will. I've seen every unique little corner, case and situation you can imagine and there's always a solution. It may be more creative and different than you think Right and that's part of my episode today is like. The awareness of it is step one, and then how to apply that to you specifically as step two.

Philip Pape: 18:09

All right, let's go to the seventh BMR fact I want to talk about, and this is related to women's health and PCOS. Pcos is polycystic ovary syndrome and you might have heard that PCOS lowers your BMR and that it makes it harder for women with PCOS to lose weight, and this comes primarily from a single study from 2009. But if we look at the totality of research on this topic, we find that PCOS doesn't appear to have a significant impact at all on BMR. The 2009 study that suggested otherwise had some methodological issues right, issues with its methods that likely lead to inaccurate results. All of this is explained in the detailed articles, so I you know again, shout out to Macrofactor if you want to go dig into that Now.

Philip Pape: 18:56

This doesn't mean that women with PCOS don't face challenges with managing their weight and their fat loss. They do, but they're more likely related to hormonal imbalances affecting hunger and fat storage you know, not a dramatically lower BMR and those can be controlled in some level via lifestyle, via how aggressively you diet, via taking breaks and going to maintenance and eating enough to recover and strength training, and on and on and on. You know more sleep, better stress and so on. So this fact again highlights the importance of you don't want to just cherry pick studies. You don't want to fear monger on one thing. You want to look at the broader body of research when you make any conclusion about health and metabolism. So those are the seven facts I wanted to share about your BMR.

Philip Pape: 19:40

But the most empowering thing about these is realizing that your metabolism isn't some mysterious force working against you. It is a complex, adaptive system and it's doing its best to keep you alive and functioning. So if you can work with your body's natural process, if you understand it and work with it instead of fighting against it, thinking that you have to force yourself to cut calories or do some crazy thing that doesn't feel right, then you can achieve better results, faster results, more sustainable, more efficient results in your fitness journey. All right, as we wrap up, I want you to remember that, even though we're talking a lot about BMR, it's definitely an important factor in your energy expenditure. It's just one piece of the puzzle.

Philip Pape: 20:23

The other pieces are your daily activities, your training and exercise and, of course, the food you eat, which all you know, like protein, which all play very critical roles in your body composition and, of course, in your health. In fact, I recently came out with an episode about carbs and I had people arguing that well, no, maybe carbs come into play with calories and expenditure, but not with health. In other words, you can eat too many carbs and it's bad for your health. And that kind of misinformation and nonsense is what I'm trying to eliminate when we have these discussions right, because a lot of it does come down to metabolism and energy balance and lifestyle. It never comes down to a specific food Again, unless you have an intolerance that you know about. But besides that, we can't generalize.

Philip Pape: 21:08

On the other hand, understanding your BMR is important because it helps you make more informed decisions about your diet and fitness routine, even though it doesn't define you. It doesn't define your potential for change. If you want to be an athlete, you can be an athlete and you can get the results you want. And then remember, if you want to take the guesswork out of calculating your metabolism and tracking your calories and macros, definitely give Macrofactor a try.

Philip Pape: 21:32

I created a free video showing you how to download and set it up for that initial maintenance phase so that you can calculate your starting calories and macros. So just click the link in the show notes for the video, or just grab the app off your app store and use my code WITSANDWEIGHTS all one word, but again you can watch the video, it'll walk you through. Or you could just go into it and have fun and use my code WITSANDWEIGHTS all one word to extend the free trial to give it a shot. Until next time, keep using your wits lifting those weights and remember that your metabolism isn't broken. It's just a bit unique for you and and I'll talk to you next time here on the Wits and Weights podcast.