I am joined by MetPro Founder, Angelo Poli. We are going to be discussing keto diets and some myths that surround keto diets. Thank you so much for joining me, Angelo.
It is a pleasure to be here, Crystal.
I am so excited to dig into keto. There’s a lot of stuff out there. By stuff, I mean lots of information. It’s very difficult to pick apart what is accurate and what is not.
It indeed can be. The hardest part is figuring out where to start. There’s so much information on it.
Am I right that keto has been around forever? It has eighteen different names, and they keep brief surfacing it as a slightly different version of itself.
You are correct. You’re going to challenge the threshold and limits of my memory here. Take with a grain of salt what I’m about to say. It was in the early 1910s or maybe 1920s. I could be off by a decade. Some Arctic explorers explored the Inuits eating waterfowl and a blubber diet from seals and things like that, and discovered what is the modern-day ketogenic effect. Throughout the years, that has been researched more and was popularized by Dr. Atkins. He didn’t invent it. This has been around forever.
It has then resurfaced. My favorite iteration is the accidental low-carb diet. Don’t take this as good or bad. It just is. There are a number of diets that circle around the paleo-style diets because a lot branch out from that, which if constructed in certain ways would also be a ketogenic diet. If constructed other ways, if you have sweet potatoes and bananas in your diet, maybe not so much.
There’s this big movement on pure keto, which is a little bit more on the science and the more extreme end of carbohydrate restriction. This entire topic is carb restriction and its impact on our metabolism, weight loss and fat loss. When we’re talking about keto, we’re simply talking about degree. Some approaches to it are more aggressive in the restriction of carbohydrates. Others are a little bit more modest. The ones that implement the most aggressive restriction result in the body producing ketones, therefore the name ketogenic.
We know that’s a more aggressive restriction of carbohydrates. We could get into the inclusion of how adding more fat impacts the whole process. We could get into the blood lipid panels and the potential health benefits and debate there. Suffice to say, it’s a very broad topic but for the purposes of our conversation, let’s look at it from the standpoint of lifestyle and people using it as a tool for either fat loss or weight loss.
We’re going to narrow that giant scope a little bit. Where do we start when we have that conversation?
It was several years ago. In preparation for this conversation, I pulled up a brief lifestyle article that we wrote for the MetPro Academy. This is posted online, Is a Ketogenic Diet Good for Weight Loss? This was a while back and it was a broad approach, but it’s short. What I thought I would do is read a few excerpts here and then we can talk about it a little bit. First of all, we get this question a lot. It’s a common question. Let’s talk about what category ketogenic falls into.
There are diets that focus on calorie restriction and diets that focus on carbohydrate restriction. Keto is a tool that’s going to be in the carbohydrate restriction category. It’s worth commenting on this. There are a million other approaches and focuses out there. Here’s the truth. The greatest impact is going to be your calories and/or your carbohydrates. Those are going to be your biggest levers. It is true there are other levers but we would classify those as accessories or optimizations. All of the research is very clear that the biggest lever is going to be calories and carbohydrates.
Coming back to the discussion, is keto good for weight loss? The truth is your past dieting history and personal circumstances influence how your body will respond to keto and other weight-loss strategies. Some people respond better to carb control than others. Without pointing to this particular research, just in the last 20,000 people we have worked with, that’s the truth. Everybody has experienced that.
There’s a lot of individuality in how somebody may respond to carb restriction. Some people are responding better and some people are responding not as good. Even more interestingly, one of the most common things we will hear is,
This is my second or third time on a ketogenic or low-carb diet. For some reason, my body is responding differently or not responding this way. There is a large adaptive response. That comes with all diet styles, but it does appear that it’s a little bit more aggressive with carbohydrate restriction.
I’ve seen that in our household. Tom, my husband, has done that. It had diminishing returns over time.
That’s one of the most common things. People will say,
Does carbohydrate restriction work? The answer is, “Yes, it works,” but it’s still going to boil down to where you have the most leverage. That answer may evolve over time. Here’s what we have noticed. Most people notice that their body doesn’t respond the same second or third time. Keto works by nudging your body to burn more fats or fuel instead of its preferred source of carbs or sugar.
That is an intense over-simplification, but for the purpose of keeping this short and sweet, we all understand the basic tenets that you’re going to burn more lipids and fats in the absence of carbohydrates and sugar in your diet. The higher fat content is satiating. That means it’s filling and it can help some people with sugar cravings. That is true. Some people more than others. We will look at some research on that in a little bit.
If you struggle with sugar cravings, you might find some value in a dieting method that focuses on carb control. The problem we find with this tool is that people don’t understand that they’re signing up for a lot of other things too once they start cutting out carbs. One thing in particular that they’re signing up for is carb sensitivity.
What does that mean exactly when you say carb sensitivity?
That’s fairly absolute. If you restrict carbohydrates, your body is going to adapt. You’re going to create a hormonal circumstance and a biological circumstance wherein your body is going to be seeking to grab any carbs that do come its way and store that for good reason. That’s a little bit of the science stuff here. Part of why there’s so much confusion around carbohydrate restriction versus calorie restriction is because one of the functions of glucose or glycogen replenishment is that each gram of glycogen stored in our muscles is buffered with about 3 grams of water.
When we deplete that sugar at the muscle site via exercise to a degree, but it’s aggressively done so by not taking in enough sugars or carbohydrates, you not only lose the sugar at the site but you lose the 3 grams of water buffered at the site. That is why somebody unaccustomed to carb restriction can restrict carbs for as little as a day or two. All of a sudden, they see multiple pounds gone on the scale.
It’s because they’re losing all the water attached.
Unfortunately, they did not lose 3 or 4 pounds of fat overnight. What they lost was water predominantly coming from fat-free mass in their muscles. That creates this psychological feedback loop, which creates a carb phobia or sensitivity in our mind because it reinforces itself,
I’ve been cutting carbs. I eat fewer carbs. I’m watching what I eat. I watch my carbohydrates. I had a weekend away with the guys or the girls. We didn’t worry about it. I indulged in wine and dinner rolls. I woke up to an extra 5 pounds of me the next day. How is that possible? What’s our first thought?
My body is uniquely allergic to carbohydrates. The truth is everyone’s body is uniquely allergic to carbohydrates under those circumstances.
It comes back. The body grabs them and puts all that water back on it. Now you have all those extra pounds back.
You end up with an entire generation of women in their 40s who have been told and indoctrinated that they are carb sensitive, which is not technically inaccurate but it creates this feedback loop or this yo-yoing of high and low carbs. It can lead to that yo-yo scenario of dieting, not dieting, and then back and forth. Even observationally more so than calorie restriction. There are a few details that are important to understand. Keep in mind that carb restriction is a potent tool. It’s one we do utilize at MetPro but very judiciously. This is not a “carb restriction is bad” speech. This is not understanding what it is doing to your body is best.
I’ll give you one quick story here. Most people are unaware that sports nutritionists take endurance athletes who are carb-loading through a prep cycle in preparation for carb-loading for an endurance event. Most people think,
That means they feed them more carbs. Most are surprised to learn that a technically derived approach is that the sports nutritionist will decrease by about 15% to 20% the amount of carbs the athlete ingests several days prior to the race or event because it sensitizes the body to glycogen or glucose uptake.
When they add it back, that’s the body grabbing onto it for that extra energy and performance.
The body will hold and hyper-impose that 10% to 15% more glycogen inside the muscles as it is seen as a scarce resource for a day or so. That’s how it’s being timed to get the hyper-imposing of glycogen into the muscles for race day. There’s a little more science to it. That creates this feedback loop. One thing that’s important to know is when you cut carbs, you’re signing up for some carbs sensitivity for that duration. When your body goes too long without having that macronutrient, it becomes sensitive to it.
A night of indulgence can result in a surprising amount of weight gain if you don’t understand how the carb restriction works. The conclusion here in the article is we see this phenomenon leading people into cycles of yo-yo dieting and rebound weight gain. Therefore, keto or extreme carb restriction usually isn’t the best choice for inconsistent dieters.
Think about the implications of that. Putting science aside, is it aggressive? Is it effective? From a behavioral standpoint, if you’re an inconsistent dieter, you will end up getting much of the carb sensitivity without all of the benefits that come with carbohydrate restriction. If you have already gone low-carb, be sure to include a reintegration period to gradually introduce carbs back into your diet.
No one does that.
Even the old Atkins approach gives the nod to having periods of summary integration, but most of them are stopping short of what most people would consider normal carb intake for their lifestyle. I usually will ask my clients,
Talk to me about your history with dieting. Are you the type of person that once you start a nutrition plan, you’re very consistent for a week or two at a time? Maybe a day here or there but on average, it’s weeks at a time of consistency. Are you the type of person that can make a bunch of small changes, but you find you have a couple of days of consistency followed by an off-schedule day, a couple of days of consistency, and an off-scheduled day?
If you are the latter, there is a very practical argument to be made that calorie control is probably going to be a more predictable and sustainable approach than carbohydrate manipulation in your case. That’s because you’re muting the process if you’re unable to stay consistent with it for an extended period of time. That’s something most people don’t think about when determining an approach.
Keto usually isn’t the best choice for inconsistent dieters. You will get sensitivity without all the benefits. If you’ve already gone low-carb and you’re like,
How do I back out of this? It’s the gradual reintroduction of carbohydrates. You can blunt any negative effects if there’s an uptick in your energy expenditure at the same time. Exercise and stop adding carbs.
Your body will acclimate to those carbs, but in the time interval that it takes your body to re-acclimate, even a small amount of additional exercise can help close that delta so you don’t have a negative response. Does this mean that low-carb dieting is a bad tool? Our comment goes on to say, “No. Low-carb dieting is not a bad tool.” At MetPro, we use carb restriction when we analyze your data and identify that it will produce the right leverage.
Your goals and lifestyle all must be considered when selecting which diet approach is best for you in this personal season of life based on your circumstance. We’re never going to pick just one tool or approach. Why limit ourselves when we can use multiple levers? Having insight into your current metabolic rate and pairing that information with your goals is going to let us identify where you personally will have the most leverage. This backs into why you will hear us talking about it on this show often and if you’ve ever worked with any of our coaches, there’s baseline testing.
That helps your coach see and understand where you’re already at so that they can make adjustments for you specifically.
It answers the question,
Does carb restriction work? As a general question, the answer is yes.
Will carb restriction work for me? The answer is, “We’ll go after baseline testing.” The answer is we’re going to find out exactly whether it will after baseline testing because we’re going to determine how much leverage.
A lot of times, it’s as simple as this. It works great for you. You’ve already played the card. Simply restricting another 15% of your carbohydrates, there are going to be marginal impacts. We have to turn a different dial now to have a significant impact and bust through a plateau. That is why sometimes, our clients will find our coaches taking them temporarily on alternate routes. That way, we can come back to some carb manipulation with good effects. It’s all about how it’s applied.
That is the magic of MetPro because it is individualized for each person.
That is the idea because we want to get somebody results. Unfortunately, what is conclusive across all research is that there is huge variability between individuals. That can be explained. It’s not some cosmic mystery that no one can know or understand. It can be explained once we look at the history and circumstances of individuals. We will share with you some of the actual research. This will be a little bit nerdier approach to the question.
We’re getting nerdy. Let’s do it.
Here’s the research. The benefits and drawbacks associated with carb restriction are well-documented. They truly are. If you go to Google Scholar and do research or query, there are tons of research on this. A Randomized Trial Comparing a Very Low Carbohydrate Diet and Calorie-Restricted Low Fat Diet on Body Weight and Cardiovascular Risk Factors in Healthy Women, this was in The Journal of Clinical Endocrinology and Metabolism of Oxford Academic.
It was demonstrated that restricting carbohydrates resulted in greater weight loss than calorie restriction alone. There it is. There’s more coming though. There’s more to it than that but there’s a reference piece. There’s another study entitled Changes in Food Cravings and Eating Behavior after a Dietary Carbohydrate Restriction Intervention Trial. This was a trial. It was observed that reductions in food cravings occurred in as little as four weeks on a carbohydrate-restricted diet. It was observed that women expressed that they experienced a greater reduction of sweet cravings than men. This is an observational study. It’s a little bit less quantifiable, but that’s very much in harmony with our experience as coaches.
The fewer sugar people have, which is carbs, then the fewer cravings that they have. It’s cyclical.
There are two feathers right out of the gate, but it doesn’t stop there. This one starts with, however. In the study, Similar Weight Loss with Low or High-Carbohydrate Diets, significant differences in weight loss between high at 45% carbohydrate intake and low at 15% carbohydrate groups were not observed. Each study is under different parameters, which is why you have to take them more holistically. How you look at studies and the eyeglass that you’re looking at it through is critical.
It shows that there is a dose relationship. We have observed this as well. For example, if you take an average individual that is eating a higher-carb diet without significant calorie restriction and you simply move them to a moderate low-carb, there may be some minor adjustments in some circumstances but overall, you’re not going to see a major shift. There’s a massive asterisk on that though.
That changes if they’re athletic and exercising because now you have two scoops going into the same bucket and amplifying the results. There’s a multitude of factors that have to be considered. Interestingly, in the study entitled Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity, a short inpatient has a little bit of extra weight with me.
It’s because it’s not just observational. They have made sure that everybody is controlled in how they’re responding.
They’re staying at the clinic. It’s short inpatient, therefore, in theory, they’re more controlled. The study resulted in more body fat loss with a dietary fat restriction even though total weight loss was greater in the reduced carbohydrate group. The total weight loss being greater is a little bit of a goes-without-saying scenario. Remember, we talked about the 3 grams of water. You’re going to experience some water loss.
Their total weight loss is likely to be greater, but then all the studies also show that if you follow that person a year later, what we’re finding is more or less parody between the two. This is a little bit more close-up view. In this one study, they demonstrated that body fat loss. They’re taking into consideration fat-free mass and fat mass and doing all the counterbalances. It statistically shows that in this case, there was a little bit more body fat loss with the dietary fat restriction. How can that be so?
A similar outcome was observed in the study, High-carb or Low-Carb, That is a Question. Greater total weight loss was observed in the carbohydrate-restricted group, while the reduced-fat group experienced less adaptation to carbohydrate and fat restriction leading to greater fat loss than the reduced carbohydrate group. In other words, in this study, there was adaption. The bodies got used to those low-carb elements. In the long run, they found a little bit more fat loss in the simple and old-fashioned calorie restriction and more balanced.
It’s because the body adapted to having fewer carbs, so it became less effective each time they tried it versus having calories restricted. That’s a different track that they’re on.
It’s worth noting that there are studies that nod in both directions. You can’t have a conversation point to a single study and say conclusively,
This is this. The take-home message is when we look at the scope and breadth of information out there from a lifestyle standpoint, an observational and real-life standpoint, and a clinical standpoint, we see that there is merit in both directions. When you hear somebody talking,
You can only lose weight by restricting carbohydrates. Any weight loss is because you’ve restricted carbohydrates. Carbohydrate restriction is meaningless. It is only total calories, what we can rule out is those few points.
We know it’s neither of those two. What do we want to leave people with then? What do they want to hang their hat on? What are we saying?
You know what I stand for. Here is a study that is a little more mathematical. We have to factor this in. The study is the Comparison of Carbohydrate-Containing and Carbohydrate-Restricted Hypocaloric Diets in the Treatment of Obesity. Endurance and Metabolic Fuel Homeostasis During Strenuous Exercise. That was the name of this research piece. What they did was they compared low calories, but one version was low-calorie with carb restriction and low-calorie with balanced macronutrient ratios.
Here’s what was observed. A significant decrease in endurance during cycle exercise at approximately 75% VO2 Max was observed in the carbohydrate-restricted group. That was not observed in the low-calorie group. Here is some additional math on this. It was noted that pre-exercise, muscle glycogen did not change significantly in the low-calorie group, but was decreased by approximately 50% in the carb-restricted group.
There’s your energy and power. That’s why the power was decreased.
The results indicate that adding significant carbohydrate restriction to a hypocaloric diet impairs performance. That means that looking at the body of research even when there’s a nod to some advantages with also including carbohydrate restriction as part of the process, there’s a dosing and threshold effect where if gone too far, we have to acknowledge that it is likely going to spill over faster than pure calorie restriction would to athletic performance, particularly endurance performance.
Granted, I know that there’s going to be the one person who sends the email and states the research on the people who have shown ketogenic adaption through the process of getting their body used to a more fat-burning metabolism. That enhanced athletic performance. That is the case. You can condition your metabolism over a longer period of time to burn. That applies to 1/2 of 1% of the population and is usually for the elite trying a very unique approach to fueling endurance athletics. The 99.5% of the population out there is going to find in their level of competition and specificity that having carbohydrates is going to result in more energy for endurance athletics across the board.
As a person who tries to do athletic things, I wouldn’t even try to do that one.
We’re not discounting that research, but aside from that level of specificity for the average person, it can be surmised that enough carb restriction combined with calorie restriction will lead to depleted muscle glycogen and reduced energy output. Seventy-percent VO2max is where it was observed. You’re going to have an impact on exercise. What we can conclude beyond contestation is exercise is key in weight loss maintenance. Therefore, I’m all about habits and lifestyle. Will I use carbohydrate restriction? I will, but not to the point where it’s going to start to undermine our habit of exercise.
Use it but it’s not the only tool, which goes back to what you said at the beginning.
Everyone’s threshold is a little different. Personal evaluation is key. What do we take away from all this? This is just the tip of the iceberg. This is page one. That’s it. Looking at the body of research, if you’re one of our readers and I knew nothing about you but your name and that you want to lose body fat or weight, I’m going to start with moderate calorie control first and ease into carbohydrate restriction only as needed. When I’ve determined that your metabolism is starting to adapt and showing adaptive responses where it’s slowing down in response to extended dieting over time, then we’re going to rev your metabolism starting with carbohydrate increase, following with incremental calorie increase only as needed and as tolerated.
Start the whole cycle over again. That’s wonderful.
We’re going to exercise. You have to have all the pieces, which is why lifestyle is key. That generalized approach is going to be much more individualized once we baseline test. We look at your history with diet and exercise and then we know where in the process we need to start.
It’s super helpful for people to understand some of the thought processes that go into this when they’re using MetPro. Also, why it’s so important to be cognizant of these factors when they’re trying to go to it alone. If you’re a person who’s like,
I’m going to go on keto or do this other thing. I’m going to do whatever diet because my friend is doing it, then it’s important to understand all of these factors so when it’s not working or when you see it stop working, you understand that’s not in your head. That’s not because you’re doing something wrong. That’s because there’s more science to it. It’s not black and white. You explaining all that helps so much for people to understand that.
What you said there is such a great point because so much of the result of either bro-science versus actual research or how marketing and the media influence our perception of weight loss and dieting modalities has resulted in unnecessary frustration if we simply understood the biology and the science behind these different modalities. Hopefully, this helps our readers a little bit. It’s always fun to talk about it.
I loved getting nerdy with you. That was great. Thank you so much for your time, Angelo. Readers, that’s all. You can find all of the MetPro Method episodes anywhere you get podcasts or you can go to MetPro.co/podcast. Please be sure to follow the show and rate and review. That lets other people know what they can expect. You can also learn more about MetPro at MetPro.co. I’ll be back. Until then, remember, consistency is key.