Full Episode Transcript
Apologies for any transcription errors!
Matt: Welcome to Nutrition for Mortals, the podcast that says life is too damn short to spend your time and attention worrying about your food choices. So let's take a deep breath and then join us to registered dietitians and friends as we explore the world of nutrition with a special focus on cultivating a healthy and peaceful relationship with food. My name is Matt Priven and I am joined as always by my co-host and the best dietitian on planet earth, Jen Baum. Hello, Jen.
Jen: Hello Matt. And just super quick reminder, if you're liking the show, please consider leaving us a nice review wherever you listen to podcasts. We are also on Instagram. You can follow us at Nutrition For Mortals and you can always email us if you have a show idea or a topic you'd like to hear us talk about at nutritionformortals@gmail.com.
Matt: Yeah, we'll do a whole show about it. Just let us know.
Jen: Let us know.
Matt: So Jennifer Baum, tell me what are we talking about today,
Jen: Matthew, we're going to be talking about metabolism and more specifically today we're going to be talking about whether or not it's possible to influence how our metabolism is working by either eating certain foods or taking certain supplements. And I think it's a really good topic for us since metabolism and metabolic health are most definitely some pretty popular health and wellness buzzwords currently. So we're definitely going to be covering a lot of ground today. We're going to be talking about Dr. Oz. We're going to be talking about The Biggest Loser. We're going to be talking about green coffee bean extract. So we've got a lot of ground to cover today.
Matt: I see in our notes "metabolism death foods" too. What the heck is, alright, I'll keep my powder dry. I'm excited to hear all about that. So you'll take us through metabolism and the influence we have over it. And there's all this language about hacking your metabolism now, and I think we might title this one: Can you hack your metabolism? Right?
Jen: Exactly right. Yeah. And we're going to really try to do a deep dive into this idea of do we really have that much control over our metabolism? So I think it's going to be a fun one today.
Matt: Yeah, good topic. Probably a good place for us to start is just tell me what metabolism is. I think everyone is able to use it in a sentence, but can you just give us a good definition of it to start with?
Jen: Sure. I think that's a great place to start. I mean, really our metabolism is all of the biochemical reactions in our body needed to support life. So very simply put, metabolism is just how our body creates energy and then goes on to use that energy to keep all of the systems in our bodies functioning. So like our heart beating and our brain working and our muscles contracting and our body has the capacity to convert lots of different fuels to energy. So we can use that energy to power ourselves. We can use carbs for energy, we can use fat for energy. Sometimes we're using a mix of both. And so it's all about getting energy from food and then using that energy to make our cells work. So actually gratitude for our metabolism. Pretty awesome.
Matt: Okay, great definition. So can we just talk a little bit about the history of metabolism in the context of diet culture? Because my guess is that that's kind of why we're talking about this today. All of the messaging that people get about how they should be trying to influence their metabolism, often trying to rev up and speed up their metabolism really kind of ties into the cultural discourse about how your food needs to be contributing to speeding up this machine and burning energy. So can you tell me a little bit about your thoughts on that or what you've come across in preparing to chat with us?
Jen: Yeah, I mean I think this is definitely the why behind why we're talking about this today because diet and wellness culture definitely makes it seem like we have or should be in control of our metabolism. And that if for any reason our body changes over the course of our lives, our metabolism is at least partly to blame and we're somehow responsible to fix it. But honestly, I feel like the idea of boosting metabolism is really just another way to dress up weight loss and dieting. I put it in the same category as balance your hormones or optimize your gut health, which we've definitely talked about on the show already. And actually, Matt, I think I'll have you read a great quote that I came across that speaks directly to this idea. This is a quote from an interview with Dr. Berna Christmas. Great name by the way.
Matt: Dr. Berna Christmas. Yes. Oh, that's going on all time great names list.
Jen: Amazing. Right. And she is an associate professor at Qatar University. She has an extensive background in exercise and sports science. She has a PhD and she spoke about this idea of kind of dressing up metabolism as kind of a PC way to talk about diet culture. So Matt, I'm going to have you read this, if you would...
Matt: Quote, the end goal of boosting metabolism really isn't using more energy. We actually want to be more efficient and conserve our energy says Dr. Christmas. Sure, we want to have good metabolic health. i.e having a system that allows us to use energy effectively. But if boosting or increasing metabolism is a goal, if it was possible, then the only possible reason would be for weight or fat loss. In other words, metabolism is just diet culture dressed up as something more pc, close quote.
Jen: Right? So I think the value in talking about this today is number one to try to answer the question of how much control do we even have over our metabolism? But also is it necessary or even helpful to be chronically focusing on metabolic health?
Matt: Yeah, I love that quote. You always hear about the body being like a car and you're trying to fuel up the engine. And so Dr. Christmas here is saying, so we're all obsessed with trying to make the car burn up its fuel faster. The only reason for doing that would be to be in a state of depletion chronically. You really want to focus on efficiency and effectiveness. And so that's a really succinct way of putting why this conversation about hacking our metabolism is really just diet culture in disguise.
Jen: Right. Well, and I also think that there has been this shift away from using the word dieting right now. It's not as "in" to be dieting. There's all these kind of alternative ways that wellness culture is dressing up dieting, and this is one of them in my opinion, which we'll definitely get to later in our conversation.
Matt: Okay, so kick us off here. Where are we going to jump into this conversation?
Jen: Yeah, I want to do some serious debunking today. And so I want to start us with a section of the episode that I am calling "metabolism death foods". Why am I calling it that? Well, let's play a clip of two people that I never want to sit down and have a beer with Dr. Oz and Dr. Josh Axe
Clip: Now you doing everything right, but it just feels like your metabolism is DOA. Yeah, I thought so. Today I'm introducing you to a man who says it is not your fault. There are surprising foods killing your metabolism. Please meet Dr. Josh Axe the man behind the controversial term you need to know about, "metabolism death foods." Most women are eating foods that are absolutely wreaking havoc on their metabolism. Dr. Josh Axe is on a mission to transform your health, A physician and certified nutritionist, Dr. Axe says he is brought his patient's metabolism back to life and can do the same for you ( cauliflower and broccoli and spinach that's really going to help you break through the weight loss plateau.) One of the biggest setbacks to weight loss says Dr. Axe is eating what he calls "metabolism death foods. These are foods that are going to cause inflammation, digestive issues, hormone imbalance, and shut down your body's fat burning potential even if you're eating less and exercising more. If "metabolism death foods" are part of your daily diet, Dr. Axe says you'll never achieve the body of your dreams.
Jen: There's so much there.
Matt: So much there. There's so much.
Jen: Yeah. So we're not going to play the entire clip. I don't think there's any point, but one of the things that Dr. Axe goes on to say is that foods like all whole grains are terrible for metabolism. Canola oil is terrible for metabolism. He even talks about how peanut butter is horrible for your metabolism and really there's no evidence to back this up. I actually got very upset.. I am neither a Dr. Oz nor Dr. Axe fan. And I went onto Dr. Axe's website and I read his opinion on peanut butter. And what I found to be so shocking is that here he is on the Dr. Oz show in front of thousands and thousands of viewers talking about how peanut butter is terrible for your metabolism. And then on his very own website, I came across this conclusion around peanut butter. So Matt, can you read this from the Dr. Axe website about peanut butter?
Matt: Peanut butter supports and boosts metabolism and fat loss if you consume it in moderation and is part of a proper diet because it's a high protein snack that provides a range of micronutrients. It's healthy when consumed properly.
Jen: So like a complete contradiction, honestly, sometimes I feel like these guys can't even keep it straight what they're saying and making up around food. It's crazy.
Matt: They forgot the grift from last week. They've moved on to a new one.
Jen: Right? Right. Or they're just like, okay, this week peanut butter's terrible and next week it's amazing. It's just so interesting to me that it's almost always about just talking about these foods incendatory way.
Matt: They know who their audience is too. It's so funny. Dr. Axe was like, a lot of women are really messing up their metabolism. It's like, why women? Dude, what are you talking about? He's clearly just preying on the demographic he knows he's reaching in that moment.
Jen: I'm so glad that you caught that too, because I noticed that as well. And it's upsetting because he definitely knows his audience. And again, he's kind of trying to play on women's insecurities, though I'm sure men are not immune to it either.
Matt: Yeah. Well, that's a rough clip. And I had to turn around because I was laughing the entire time because Dr. Oz just makes me laugh so much despite the fact that I disagree with everything he says. He's hysterical. So I am always here for a Dr. Oz video, to be honest.
Jen: Yeah. Well, okay, let's play one more example of the typical type of messaging around metabolism boosting foods. Matt, I chose this one for you because it is a terrible TikTok video with loathsome background music that I know you completely hate. And so let's just give one more example about the way that certain foods are talked about in relation to metabolism, especially online right now.
Clip: I think you may have a slow metabolism. Here are seven foods that can help speed it up. Chili peppers are a source of capsaicin, the compound that gives them that heat and also comes with some unexpected health benefits. One is the ability to increase the rate. Your body burns calories according to research. Whether you like black, green or oolong tea regularly sipping a hot mug can help rev up your metabolism. The antioxidants found in tea and caffeine work together to increase the rate you burn calories. It turns out your morning brew doesn't just perk you up, but it can also increase the rate. You burn calories, coffee beans, have antioxidants.
Jen: Yeah, she just goes on and on. It gets very sleepy and boring. She just keeps listing off foods.
Matt: Yeah, that is the most boring clip ever. Thank you, Jen.
Jen: Yeah, no problem. No problem. But that is very kind of representative of the type of content that's floating out there around metabolism boosting foods. And I really want to hit this home before we move on is that despite the fact that you can find 1,000,001 claims around certain foods that are supposed to boost metabolism, the truth is that our metabolism is tightly regulated and the speed of your metabolism remains roughly the same regardless of what you eat. And there may be some foods that have a very small temporary effect. For example, there have been some studies that have shown that caffeine may slightly increase metabolic rate in the short term, but the truth is your body becomes used to caffeine over time. So the effect doesn't last if you're a regular caffeine drinker. So this idea that there are metabolism boosting foods or "metabolism death foods," it's just honestly utter nonsense.
Matt: Yeah, that's such a good point. And there's been so much coverage of foods that speed up metabolism. Every website you go to, if you scroll down far enough, you see a picture of a rotten banana and it says these foods are killing your metabolism. And it's like these foods have almost no impact on your metabolism, is the ultimate takeaway.
Jen: That's exactly right. And so I think we can really put to rest this idea that anything we eat or put into our bodies is going to significantly impact our metabolism or our metabolic rate in any way, shape or form.
Matt: Yeah. I mean, we need food to use our metabolism to create energy. So eating is important. You have to eat and that helps you move your metabolism along. And there's certainly an influence that maybe I'm sure we'll get to about not eating enough and the influence that has on metabolism, but these specific food interventions of eat this to speed up your metabolism, it's just so oversold. And it sounds like you did a good lit review here and really turned up nothing.
Jen: Right. Well, and even some of the, I guess the more researched food items like caffeine containing beverages or green tea, I mean even those, the evidence is so weak and they're pulling from studies that were done in five people in the 1980s. And so I think it kind of goes back to a point that we've made on the show a number of times is that there's never going to be one food that solves every health problem, nor is there going to be one food that somehow destroys your health.
Matt: Okay. So where are we going to go next in our debunking journey here? I hope I don't really have to hear the term "metabolism death foods" ever again because that's so ridiculous. But where should we hop to next?
Jen: Yes, we are done with "metabolism death foods", and we are going to move on to talking about metabolism boosting supplements and this kind of whole class of supplements that are supposed to be either good for supporting our metabolic health or good for burning fat. And I think that what we need to acknowledge is that really what we're going to be talking mostly about is the category of supplements that are often referred to as fat burners. And we actually touched on this when we were talking to Michael Ulloa in our counting down toxic fitness trends. He touched on how prevalent fat burners are in the fitness community and how there's really not any evidence to support these type of supplements. But I did spend some time online looking at all of the supposed supplements that are supposed to help boost metabolism. And I did not create a montage of chaos like we did in our social media episode. But are you ready to hear the list of supplements that I found in that 10 minute stint online that are supposed to increase our metabolic rate?
Matt: Yes. Wait, do you want to play it as a game where I can, should I check guess some or are you just going to hit us with a list?
Jen: Actually, yeah, I bet you can guess at least five
Matt: Raspberry ketones.
Jen: Definitely.
Matt: Garcinia Cambogia.
Jen: Yep. Absolutely.
Matt: I'm already running out.. green coffee extract.
Jen: Obviously.
Matt: And then there's probably some more tame ones. Just like EGCG.
Jen: That's right.
Matt: Alright, I'm tapped now.
Jen: Okay. But you're also missing some amazing ones like sea moss gel and conjugated linolenic acid, bitter orange extract, Oxy-shred, lion's mane, our good old friend, apple cider vinegar, black seed oil, turmeric. So I could just actually keep going. The rest of the episode could be me listing off what types of metabolism boosting supplements I found online.
Matt:Yeah. So how are we going to demonstrate some of the supplement offerings to our audience here?
Jen: Well, I guess I first want to start with the fact that research around all of these types of supplements that I just named is just lacking. I don't actually even know how to put it besides, there's just no, almost no evidence at all behind any of these things. I mean, a lot of the companies that are making claims about these supplements are either pulling from animal studies or studies that are done in cell culture, or even studies that were funded by the company selling the product, which of course is like no bueno because they're just going to be chock full of bias. But I thought it'd be really interesting to use to bring Dr. Oz back since you always laugh at his voice and I can't stand him, but he's one of the worst offenders of people who speak about these type of supplements, almost like it's fact or it's known that these supplements are going to impact our metabolism or burn fat. And so I thought he'd be a good example for us to use because like I said, he's a terrible offender, but also because he got into a ton of trouble back in 2014. Do you remember that Matt, when he went to the Senate and got in a ton of trouble about the claims he was making on the Dr. Oz show?
Matt:At the time, he didn't want to go to the Senate versus the time he tried to get into the Senate?
Jen: Yes, that's right. Two very different scenarios for Dr. Oz.
Matt: Yes. I'm glad they shook out the way they did.
Jen: Yeah. So I thought it'd be kind of fun to play an example of how he talks about one of these supplements. So we're going to play a clip of him talking about green coffee bean extract on his show that Dr. Oz show. And then we're going to walk through what happened with these claims.
Matt: And if people listening are really triggered by Dr. Oz's voice, just imagine you're watching a Tim and Eric episode or a Dr. Steve Brule segment, and I think you'll enjoy it a lot more.
Clip: You may think magic is make-believe, but this little bean has scientists saying they found the magic weight loss cure for every body type. It's green coffee beans. And when turned into a supplement, this miracle pill can burn fat fast for anyone who wants to lose weight. This is very exciting and it's breaking news. Millions of you love coffee, but now you're going to love it for a whole other reason. A staggering newly released study reveals that the coffee bean in its purest raw form may hold the secret, the weight loss that you've been waiting for. This study presented at a meeting of the world's largest scientific society triggered unprecedented excitement for a weight loss study. It showed women and men who took green coffee extract lost an astounding amount of fat and weight, 17 pounds in 22 weeks by doing absolutely nothing extra in their day. Could this be the magic weight loss bean to help melt away unwanted pounds that you've been waiting for?
Jen: So Matt?
Matt: Yeah. Yep.
Jen: You know how he talks about the article that was unprecedented and rocked the scientific community across the world?
Matt: Yeah. Tell me all about it.
Jen: Okay, so are you still laughing at his voice? Be real. You can't keep it together. When he talks...
Matt: Everything he says gets me. My favorite part is he goes "this little bean."
Jen: Yeah. So over the top with everything he says. Okay. Okay. So deep breath. Okay. So I of course went to find this article that rocked the scientific community since I'm in the world of nutrition, and I wanted to see the claims and the study findings. And when I found the article right across the front, it said "Retracted." Because it turns out, let me actually send you a quote to read from a 2015 article that I found from the Journal American Family Physician read this quote and let's just see what happened with that particular study.
Matt: The article was retracted in 2014 after a Federal Trade Commission settlement. It turns out that the company who made the extract paid a researcher in India to conduct this study. And the authors allegedly falsified the data, wheat measurements, treatment arm, trial length. When the original author couldn't get the study published, the company hired two more researchers to write the study results for publication. Oh my gosh.
Jen: So bad. So bad. And we're not going to play any of the clips from his Senate hearing, though I was very tempted to do so. But it's hilarious because he actually holds up this article at one point in defense of green coffee bean extract. And literally this article was completely fabricated.
Matt: "This little bean!"
Jen: This little bean is a fraud!
Matt: Is a fraud. There's no research actually. This is all fake.
Jen: Yeah, exactly. Yeah. So this is just really an outrageous example of just how separate the claims were from what Dr. Oz was saying about green coffee extract. But yeah, but it goes, to me, it goes even further than that. I actually found a great summary of a 2013 article. Matt, I'm going to have you read a quote that speaks to not just this one specific instance of Dr. Oz making a claim, but just his claims generally. So can you read this quote that I just sent you?
Matt: Quote, in 2013, a team of researchers at Georgetown University analyzed the various health recommendations made on Oz's show, finding that about 78% of those recommendations did not align with evidence-based medical guidelines, society recommendations, or authority statements. In 2018, without admitting liability, Oz agreed to pay 5.25 million dollar settlement in a class action lawsuit alleging that he misrepresented the efficacy of two weight loss pills, which he had referred to on his show as revolutionary fat buster and magic weight loss cure.
Jen: Yeah. So I mean, obviously Georgetown University wasn't just looking at his claims around fat burners or metabolic support supplements. They were really looking at all the claims that he was making, but still, I mean, really kind of outrageous, the fact that almost 80% of the recommendations that he was making on his show didn't align with evidence-based medicine.
Matt: Yeah, it's just entertainment. And he knew that, but you can't mix entertainment and science and then sell supplements on top. It's just not ethical. It's all not okay.
Jen: Yeah, and I think probably important for me to say that he actually has never sold supplements, but..
Matt: I don't care, he has sold supplements. Did he personally benefit from the sale of those supplements or did he benefit financially in tangential ways? He sold the supplements.
Jen: Yeah, yeah. No, that is really true. And so I think as we kind of wrap up this conversation about metabolism boosting supplements, I just want to highlight a couple things. And the first is, this is just another example of how often the supplement industry is not just a head of science and research, but it's just completely separate from it. And to me, again, one of the biggest red flags is are words like magic cure or miracle pill. I mean, these are always just code for snake oil. And so the truth is that none of these supplements are going to do what they say they're going to do. They're, we just don't have evidence to support the use of these types of supplements in supporting metabolic health.
Matt: Yeah, absolutely. So great summary of what we've seen with supplements with Dr. Oz and Green Coffee Extract being a really good example. So if we're crossing supplements off the list here, what else should we be talking about in the world of wellness and how it markets hacking our metabolism and sort of this conversation we often hear today, especially online.
Jen: So yes, I think that we can very confidently cross off "metabolism death foods." See, I said, I wasn't going to say it again, but I brought it back. I think we can very confidently say that there are not going to be any evidence-based supplements that are going to boost metabolism or burn fat. But the last category that I really want to talk about is technology that's supposed to hack your metabolism. And I think that the best example of this is a device called Lumen. Matt, are you familiar with Lumen?
Matt: Yes. I'm so glad we're talking about the metabolism vape.
Jen: Yes. Because that's really what it looks like it is like a vape pen or a portable breathalyzer. That's what it looks like.
Matt: Yeah, totally. I'm glad we're talking about this. This needs to be discussed if we're talking about hacking our metabolism, that's kind of where my head went originally. So much marketing about literally hacking your metabolism with Lumen.
Jen: Well, that's kind of their tagline. I mean, their tagline really is the device that will help you hack your metabolism. And so why don't we go ahead and play a clip of a lumen advertisement so people that maybe haven't heard of this little device can know what it's all about.
Clip: Eat only raw food, nothing but plant-based. Eat high fat, eat low fat, eat six meals.. take a deep breath and hold it. Right now you hold in your lungs the secret to sustainable weight loss. You could breathe out now, this is Lumen, the first device for hacking your metabolism with just one breath lumen tells you what you're currently burning for energy, carbs, or body fat so you can see what's going on with your metabolism in real time and what to do about it. Breathe in the morning to get a personalized nutrition plan for the day one that's on your personal goals and adaptable to your eating habits. Breathe before meal to see how the last one affected you and get recommendations to keep your body on track.
Jen: Alright, so that's Lumen. And let me give a little bit of background on the company and how the device is supposed to work. Again for those folks that may have not heard about this before. So Lumen is a company that was founded in 2014. It's based out of Tel Aviv, Israel. And it was developed by two twin sisters, the Mor sisters, who are pretty high performance athletes. And they wanted to essentially develop a device that would, as it says, try to help people understand their metabolism and how it works. You're supposed to breathe into it like the ad says, and it's supposed to measure the carbon dioxide concentration of your breath. And from that carbon dioxide concentration, it can determine what fuel your body is currently utilizing for energy, either carbohydrates or fat, or a mix of both. And the idea here is that if your carbon dioxide concentration is high, when you breathe into this device, it means that you're using carbohydrates for fuel. And if the CO2 or the carbon dioxide levels is on the lower side, it means you're burning fat for fuel. So does that all make sense so far, Matt?
Matt: It makes sense to me. I remember learning about respiratory quotient and how this works. I would imagine it's probably novel information for some people listening.
Jen: Right. So I mean, a very simple way to put it is that it's measuring carbon dioxide in your breath when you exhale and from that information determining what your body is using for fuel currently. And then of course, every technological device out there, it links to an app that you put on your phone and of course you have to pay for, and it uses a scale of one to five to indicate what fuel you're burning. So if it gives you a one, that means you're burning fat, and if it gives you a five, it means you're burning carbohydrates. And then the app goes on to make dietary recommendations based off that information. So I'll give you an example because of course I took the lumen quiz and I did a deep dive into the website, but it may tell you, okay, you're still burning carbs from yesterday, so you should have a low carb day today. Or it might say something like, don't add carbs to dinner because you're burning fat right now. So I mean, that's the basic idea of how it works. And again, it's supposed to help you understand your metabolism and the fuels you're using at different times, and then you're supposed to make these food choices based off of that data.
Matt: So do you think Lumen works the way it says it does? I mean, what do you think about just the science and technology here of expelling CO2 into a little vape pen and then having it sort of translated by them? Do you feel like that's appropriate and makes sense?
Jen: Yeah, I mean, the idea of using exhaled carbon dioxide as a measure of fuel utilization is something that's valid. It has been used in a lab setting for a long time. It's a technique that we would call indirect calorimetry. So essentially what Lumen is claiming to be is just kind of a small, fast portable way of conducting indirect calorimetry,. It's not exactly the same but I did find three or four validation studies that the company did. And so do I think it's doing what it says it's doing? I think probably it is. I think it's probably measuring CO2 or carbon dioxide to an extent, though probably not as accurately, of course, as it would be in a lab setting.
Matt: Yeah, gotcha. And it's not measuring oxygen, it's measuring just CO2 output, right?
Jen: Yeah, that's correct. And then again, it's kind of making recommendations based on how it translates that measurement into what your body's using for fuel and then how you should eat subsequently.
Matt: Gotcha. So I mean, that's worth noting, right? It's missing a core component of the formula for gas exchange here, right? You're supposed to do math based on oxygen intake and CO2 output and the relationship is where all the math is, and it's missing half the equation here. I mean, that's worth noting, right?
Jen: For sure, for sure. I also think that, so I haven't told you this yet, but I infiltrated the Lumen Facebook group. So I became part of the Lumen Facebook group because I actually really, I wanted to understand how people felt using this device in the real world. I mean, being very honest, there were some people who were very happy with it and thought it was very much value added, and there was just a whole other subset of people that were so confused. They were just like, there was this poor one woman she posted and she was just like, I don't even really know what I'm supposed to be getting from this data. And so I just think it's a very complex way to present this information. I also just think it's very confusing for many people as well.
Matt: And so it does boil down to somewhat actionable eating recommendations at the end of the day. I mean, they're not just giving you the number of the respiratory quotient, CO2 output. They're telling you, well, based on what we've done on the backend here, have a low carb day. Right? That's what you were saying?
Jen: Yeah. And like I said, I took the lumen quiz. We love a good quiz on Nutrition For Mortals, and without even purchasing the Lumen device, which I was not going to do because the whole package costs like $500 for the app and the device by the end of the quiz, it was recommending that I fast more and have more low carb days just based on my answers to these questions. And so to me, I felt like, how is this really different than a low carb diet or intermittent fasting? It didn't feel like vastly different recommendations, though I guess it was some more data-driven way of making those choices. Supposedly...
Matt: This is the most complicated version of diet culture. It boils down to eat less and eat less carbs and skip breakfast, like classic modern diet recommendations. But it does so after you have to do this it advanced formula of your CO2 output.
Jen: Right. Well, I think I have a couple problems with lumen. I mean, one, as I said, I think it's very, very confusing and it sounds very restrictive, and you and I do not restrictive diets just in general, but I also think there's this idea that giving kind of singular data points with no context, because the truth is there are lots of things that affect metabolism. We're going to talk about a few of those later. But just getting a point in time without understanding activity level or stress level or maybe chronic conditions that affect fuel metabolism like type two diabetes, then if you're relying just on one single breath measurement or even a couple points over the course of the day, it just feels very oversimplified and kind of very unlikely to give you meaningful results.
Matt: We've talked about all these things that don't impact our metabolism, which I think was important to go through and say, okay, these supplements or avoiding these foods or eating these foods is not going to, in any statistically significant way impact your metabolism. But what does impact our metabolism? I think we should hang on that a little bit before we move forward. So can you tell me what factors do impact our metabolism?
Jen: So yeah, that's a great question because we have done a lot of debunking, and so I think it also makes sense for us to talk about what factors can or do impact our metabolism. So the first one I would say is genetics. There are definitely genetic components to metabolism or metabolic rate. Biological sex makes a difference. So men tend to have a higher basal metabolic rate than females. Activity level, so particularly those people who engage in a lot of strength training or muscle building tend to have a higher metabolic rate. Sleep can play a big role. And the other one is that chronically dieting or reduced caloric intake over time can definitely decrease our metabolic rate. So there actually are a lot of factors, though most are out of our control.
Matt: So these aren't things that we're putting into our body like food or supplements. They're just sort of factors that of your environment or of your genetics that influence or I suppose your behavior that influence your metabolic rate. And so the last one being chronically dieting or reduced calorie intake does ultimately have an influence and that influences decreasing your metabolic rate. And so let's hang on that a little bit more. I think a lot of people, maybe people listening have engaged with diets in the past for weight loss or some kind of caloric restriction. And so tell me a little bit about how that works.
Jen: Yeah, I think the best example of this, or one of the most interesting examples of this is a 2016 study where researchers followed contestants from The Biggest Loser, which we teased at the beginning of the show that we're going to talk about. And so here it is, and Matt, I'm sure you remember the show very well.
Matt: I didn't watch it, but yeah, you can't avoid it in this line of work.
Jen: Yeah, yeah, exactly. Exactly. And so there was a 2016 study where researchers followed the contestants from season eight of the show, and they actually followed them for six years after the end of the competition to see what happened to them after they lost so much weight. And they were particularly interested or focused on understanding what happened to their metabolisms. And this is a smaller study, but it's also a very unique study because it's a population of people who went through some very extreme caloric restriction, some very extreme exercise for a long period of time, and then were followed for years after the end of the show. And so, Matt, why don't I have you read a quote from that 2016 study to see what the researchers found?
Matt: Quote, we found that despite substantial weight regain in the six years following participation in The Biggest Loser resting metabolic rate remained suppressed at the same average level as at the end of the weight loss competition. Mean resting metabolic rate after six years was 500 calories per day lower than expected based on the measured body composition changes and the increased age of the subjects. Those with greater long-term weight loss also had greater ongoing metabolic slowing. Therefore, long-term weight loss requires vigilant combat against persistent metabolic adaptation that acts to proportionally counter ongoing efforts to reduce body weight.
Jen: So there's a lot there. And so let's talk about it a little bit more and summarize. And so it kind of simply put, what this study found or showed was not only that metabolism slows drastically following significant weight loss and caloric restriction, but also that regaining back that lost weight doesn't restore metabolism back to pre weight loss levels. And this is pretty interesting. It's pretty fascinating, and I think it actually speaks to just how detrimental chronic dieting and extreme caloric restriction can be to our metabolisms over time.
Matt: Yeah, absolutely. So another way to put this would be if these contestants of The Biggest Loser were to attempt the same challenge again after weight regain, it would be 500 calories per day harder to do the same thing.
Jen: That's right. Yeah, that's right.
Matt: And these people were on pretty low calorie diets to begin with during this challenge. So you kind of ratchet down the metabolic rate, and so it becomes harder and harder over time to experience the same weight loss. And I think a lot of people see this in their own lives where they say, well, that first time I went to Weight Watchers was so easy, and now it doesn't seem easy anymore. People hear this, I think often, and they say, okay, well, you're saying that if I attempt to lose weight, then I'm just going to back myself into a corner. What would you say to somebody who feels that way?
Jen: Well, I would say that it's very understandable in our culture to want to lose weight. And I think it makes a lot of sense, particularly since we are told usually from a very young age that we should be dieting or chronically trying to lose weight and shrink our bodies. And so I would definitely really want to validate those feelings of, yeah, no, it's very understandable to want to lose weight. It's very understandable to want to diet. And at the same time, I think there are a lot of consequences both physically and mentally of chronically dieting that can definitely impact someone's health. And so again, I think it's a perfectly normal thing to want to do. And again, I think if we're really talking about holistic health in the longterm, I think moving away from dieting can often feel good for people, even though it's really hard.
Matt: And people who desire to lose weight, they come from all walks of life and they have all different types of behaviors. And so you and I, and our practice as dietitians, our goal is to help everybody take great care of their body and eat healthfully and move their body and feel great, and really live a life that feels connected to self-care. But that's very different than what we're talking about right now with chronic dieting. And some people who desire weight loss, they're already eating quite healthfully. And so we have to acknowledge that and this desire to force weight loss through calorie restriction. At the end of the day, we just have to appreciate the fact that that has an impact on our metabolism that is going to likely be lasting for a lot of people.
Jen: Yeah, it's a great way to put it.
Matt: Yeah. So earlier when we talked about the impacts of various factors on our metabolism, we listed chronic dieting and calorie restriction as something that decreases our metabolism. But the inverse is also true. If we eat enough, then our metabolism speeds up to compensate for that energy coming in. And I think the more metaphorical way to put this is our body starts to feel safe, and our body starts to feel that it doesn't need to conserve. And so when it feels safe, our metabolism increases. And it's very touchy to make that point because I think people who have been aspiring towards weight loss, it feels like, oh, well, that's the ticket. Now they're just grabbing onto anything that they can, which is so understandable. But really it's not about the endpoint when it comes to body weight. It's just about does our metabolism get impacted by these different factors? And eating enough would be something that would increase one's metabolism.
Jen: For sure. I mean, I can use an example. So for people who have eating disorders and are really, really severely restricting caloric intake, I mean, our body really adapts to that. Our body really tries to slow everything down in an effort to conserve energy, so our digestion slows down and we become really tired because our body doesn't really want us to move around a lot and expend energy. And so you're exactly right. The inverse of that is adequately nourishing ourselves eating enough. I don't think we would say it's good for our metabolism, but it just keeps our metabolism running effectively and efficiently versus when it's in a starvation state or a semi starvation state, and it just tends to slow down in response to, like you said, keeping us safe.
Matt: And I want to call out for those people who are like, are you going to talk about macronutrient distribution and protein needs? No, we're not going to talk about that.
Jen: Not this episode, maybe later..
Matt: Not this episode. But I don't think it changes anything about what we're saying. Right. We are saying nourish yourself and don't worry about hacking your metabolism.
Jen: Right, right. Well, now I think we're moving into the hot takes section of the show. So Matt, as we wrap up, is there anything that you want to say around metabolism and hacking your metabolism as final thoughts?
Matt: I'll just reiterate your important point that this is just another window dressing for diet culture 99% of the time. And so it's important to keep that in mind. So many things we've talked about, whether it's hormone balancing or gut health or whatever it is, there's so much that's just obscuring this weight loss conversation, and this is a big one. So I just wanted to hit that home. But what about you? Any hot takes to lead us out here?
Jen: I don't like this idea that there's this normal metabolism that we should be aiming for some somehow. I don't like the narrative that somehow we need to achieve optimal or normal metabolism, because as we mentioned, there are a lot of factors that are out of our control that impact our metabolism and our metabolic rate. And so every unique individual is likely going to have different factors that will impact how their metabolism is working and functioning. So I think we need to move away from a language that implies that there's one end goal for metabolism that we should all be shooting for.
Matt: Yes. Very important point.
Jen: Yeah, and I hope that this episode has definitely helped people do some debunking. I know we went on a huge journey from Dr. Axe to Dr. Oz to green coffee bean extract, but hopefully people are feeling a little bit better about not hyper-focusing on their metabolism.
Matt: Alright, see you in the next one, Jen.
Jen: See you, Matt.
Clip: This little bean has scientists saying they've found the magic weight loss cure for everybody type. It's green coffee bean.
Matt: Nutrition For Mortals is a production of Oceanside Nutrition, a real life nutrition counseling practice in beautiful Newburyport, Massachusetts, where we provide individual nutrition counseling, both in person and online via telehealth. Feel free to learn more about our oceansidenutrition.com. If you want to send in a show idea, you can email us at nutritionformortals@gmail.com. We're on Instagram at Nutrition for Mortals. If you dig in the show, tell a friend. Maybe give us a nice review on Apple Podcasts if you can. Thanks for listening. We'll see you next time.
