Episode 325: Dr. Paul J. Arciero, Protein Pacing Diet, Vegetarianism, Metabolism, Caloric Restriction, Intermittent Fasting, Mindset, Antioxidants, And More!

Intermittent Fasting


Help Make The Intermittent Fasting Podcast Possible!

Hi Friends! We put a ton of time and energy into researching and producing The Intermittent Fasting Podcast. You can help support us on Patreon! Every dollar helps!

Jul 09

Welcome to Episode 325 of The Intermittent Fasting Podcast, hosted by Melanie Avalon, author of What When Wine Diet: Lose Weight And Feel Great With Paleo-Style Meals, Intermittent Fasting, And Wine and Vanessa Spina, author of Keto Essentials: 150 Ketogenic Recipes to Revitalize, Heal, and Shed Weight.

Today's episode of The Intermittent Fasting Podcast is brought to you by:

LMNT: For Fasting Or Low-Carb Diets Electrolytes Are Key For Relieving Hunger, Cramps, Headaches, Tiredness, And Dizziness. With No Sugar, Artificial Ingredients, Coloring, And Only 2 Grams Of Carbs Per Packet, Try LMNT For Complete And Total Hydration. For A Limited Time Go To drinklmnt.com/ifpodcast To Get A FREE Sample Pack With Any Purchase!

INSIDETRACKER: Get The Blood And DNA Tests You Need To Be Testing, Personalized Dietary Recommendations, An Online Portal To Analyze Your Bloodwork, Find Out Your True "Inner Age," And More! Listen To My Interview With The Founder Gil Blander At Melanieavalon.Com/Insidetracker! Go To insidetracker.com/ifpodcast For 20% off InsideTracker’s new Ultimate Plan—complete with estradiol, progesterone, and TSH.

To submit your own questions, email questions@IFpodcast.com, or submit your questions here!! 


BEAUTYCOUNTER: Keep Your Fast Clean Inside And Out With Safe Skincare! Shop With Us At melanieavalon.com/beautycounter And Use The Code CLEANFORALL20 For 20% Off PLUS Something Magical Might Happen After Your First Order! Find Your Perfect Beautycounter Products With Melanie's Quiz: Melanieavalon.Com/Beautycounterquiz
Join Melanie's Facebook Group Clean Beauty And Safe Skincare With Melanie Avalon To Discuss And Learn About All The Things Clean Beauty, Beautycounter And Safe Skincare!

LMNT: For A Limited Time Go To drinklmnt.com/ifpodcast To Get A FREE Sample Pack With Any Purchase! Also For A Limited Time Grapefruit Salt Is BACK! Also For A Limited Time Grapefruit Salt Is BACK! Learn All About Electrolytes In Episode 237 - Our Interview With Robb Wolf!

INSIDETRACKER: Go To insidetracker.com/ifpodcast For 20% off InsideTracker’s new Ultimate Plan—complete with estradiol, progesterone, and TSH.

The Protein Pacing Diet

Dr. Paul's Background

the world of nutritional science

studying 7 day Adventists

Bioavailability of amino acids

protein pacing - bolus vs. distributed

combing intermittent fasting with protein pacing

protein before bed

the contrary schools of thought

autophagy provided amino acids

water fasting vs protein pacing + fasting

exogenous and endogenous antioxidants

caffeine intake

meal replacements vs whole foods

leptin levels and resistance  

the microbiome & GI distress

Our content does not constitute an attempt to practice medicine and does not establish a doctor-patient relationship. Please consult a qualified healthcare provider for medical advice and answers to personal health questions.


Melanie Avalon: Welcome to Episode 325 of The Intermittent Fasting Podcast. If you want to burn fat, gain energy, and enhance your health by changing when you eat not what you eat, with no calorie counting, then this show is for you. I'm Melanie Avalon, biohacker, author of What When Wine, and creator of the supplement line AvalonX. And I'm here with my cohost, Vanessa Spina, sports nutrition specialist, author of Keto Essentials, and creator of the Tone breath ketone analyzer and Tone Lux red light therapy panels. For more on us, check out ifpodcast.com, melanieavalon.com, and ketogenicgirl.com. Please remember, the thoughts and opinions on this show do not constitute medical advice or treatment. To be featured on the show, email us your questions to questions@ifpodcast.com. We would love to hear from you. So, pour yourself a mug of black coffee, a cup of tea, or even a glass of wine if it's that time and get ready for The Intermittent Fasting Podcast. 

Hi, friends. Welcome back to The Intermittent Fasting Podcast. This is Episode number 325, and we have a special episode today. I am not just here with my fabulous cohost, Vanessa Spina, but we have a very special guest on the show. This is actually the first guest that Vanessa and I have had together. So, we are very excited. We're here with Dr. Paul Arciero. And so, here is the backstory leading up to this conversation. Vanessa had actually been reading and sharing Dr. Arciero's work for quite a while. She shared a study on her Instagram. It published back in December of 2022 called Intermittent fasting and protein pacing are superior to caloric restriction for weight and visceral fat loss. And she posted about this, was talking all about it. So, then I read it and dove deep into it. And so then, we're talking about it on this show, and I thought why not just reach out to the head researcher and see if maybe he would entertain some of our crazy questions?

First of all, just so excited about the study. And second of all, had quite a few questions about the setup and all of that. Dr. Arciero was so kind. He responded to our emails. He actually already went on Vanessa's show, the Optimal Protein Podcast, and he was open to coming on this show, which was fabulous. I didn't realize at the time his work expands way beyond the window that I had seen, because my first exposure was reading this one study. So, then I dived deep into, I mean, not all of his studies, because he has over 70 peer-reviewed publications. So, I didn't read all of them, but I read quite a few of them. And he also has an incredible book called The Protein Pacing Diet. I didn't know exactly what to expect when I started reading it. I figured it would be about protein pacing, but friends, it dives into so many things. So, the entire concept of human metabolism, specifically how protein relates to it, and all the nuances you could ever want to know about protein. Also, caloric restriction, intermittent fasting, the importance of diet quality, exercise. 

Then beyond that, a lot of really powerful work on mindset, actually. I just loved it. It's really funny, Paul. I was reading it and sending Vanessa screenshots of the book because your vibe in the book is like the vibe of Vanessa and I. I don't know, we are into the-- It was just really beautiful. Your book is very beautiful and motivating and very high spirit. So, we're just so honored to have you here today. So, thank you so much for being here. 

Paul J. Arciero: Wow, that was one of the best intros I've ever had, Melanie. Thank you. That was really cool. You brought a word to my Zen. Yeah, it's interesting. Research sometimes can be obviously very cold and unfamiliar to a lot of people, just because it's hard for a lot of people to relate to. Whenever they start to see statistics and numbers and science, they run. And so, I really appreciate those words. Those mean a lot to me, because I want to try to make science more comfortable and harmonic with everyone's life. I think there's such a disconnect with science and research, with people's habiting of this world. And so, yeah. No, that was awesome. That was wonderful. That's my goal. So, I appreciate the shoutout to my book. I'm interested to know. I wrote two books, The Protein Pacing Diet and then The PRISE Life. And The PRISE Life was the shorter version of The Protein Pacing Diet. So, I'm not sure which one you have your hands on. 

Melanie Avalon: I read The Protein Pacing Diet. Which one did you do first? 

Paul J. Arciero: That was the one, The Protein Pacing Diet. And then, The PRISE Life was just a revised version of it, but yeah. Well, thanks again for having me. It's always a joy for me to be able to share my research, because oftentimes as a scientist our research is only shared with likeminded scientists. [chuckles] It doesn't get into the eyes and ears and minds and souls of the world that needs it. And so, I'm really grateful for you having me on. 

Melanie Avalon: We are grateful for you, because this is exactly, I think, what the world needs. You just said all of it just now. There's just so much fascinating information happening in the science world, and I think it can be often hard to bridge the gap between that world and all of the people not in that world. That's one reason I love podcasting, for example, is because we can do awesome interviews like this, and bring your work to our audience. I'll have to check out the new version of the book. And so, a little bit about your bio for listeners. So, we just learned this. Congratulations to Paul. So, he was/still is the Professor in the Department of Health and Human Physiological Sciences at Skidmore College. He actually just accepted a position as well at the University of Pittsburgh in the Department of Sports Medicine and Nutrition with tenure, which is super cool. 

Like I said, you've had over 70 peer-reviewed publications on PubMed, cited over 6,765 times. Your research has been all over the place, BBC News, WebMD, the Today's Show, USA Today, Time, all the places. So, we are very, very honored to have you here. A question to start things off. So, like we were just talking about, you really bring the human perspective, and I like that you use that word, Zen, to everything that you're doing. So, growing up, did you always want to be a scientist? Yeah, what led you to what you're doing today? 

Paul J. Arciero: That's a great question to start with because people that know me know that I was on the opposite end of a studious young boy and on his way to becoming a scientist. Yeah, I didn't fare too well in school. School was a really rough part of my life growing up. I wasn't a good student at all. I was actually asked to stay back in the third grade. So, I struggled with school, with learning. And so, what I did was I dove into my physical body, just because I was a decent athlete, and that seemed to allow me to find an identity as a young boy, because otherwise, I would have had literally nothing in terms of identifying as something worthwhile. And so, thank goodness that at least from a physical standpoint, I was able to-- So, as it turned out, I was good enough in college to get a full tennis scholarship. But then reality set in, once again when I was in college, and I ended up dropping out, just because-- Well, it was either me being asked to leave or me leaving on my own. And so, I ended up leaving and going over to Europe and playing some tennis, professional level tennis, and became very homesick. 

I was 19 at the time. So, I tried my first try in college. Didn't go so well. And then when I was over there playing tennis, thinking that this was one way to help get myself back together, I just became extremely homesick and despite having some actually pretty good success. So, when I returned home, I knew there was only one thing I needed to go back to, and that was trying to see how well I could stay in school and see if something stuck this time. Fortunately, I was really into nutrition and fitness, because I wanted to become a better tennis player. When I did return back to college, I realized that those two things were actually majors in college, exercise physiology and nutrition. So, that just started my path. And so, it was really just born out of my own personal need to find an identity and so that's how my path to becoming a scientist in the field of nutrition and exercise physiology started. 

Melanie Avalon: Wow. That's a very unconventional path, I feel. So, when you first got into that, because there're so many topics in the world of nutrition and there's so much controversy and different opinions, what has your experience been like in that world? Because you focus so much on the power of protein. Did it take a while to come to that thesis or have your thoughts oscillated a lot throughout your journey? Just wondering what that was all like. 

Paul J. Arciero: It was actually quite interesting. So, when I was over in Europe, I was becoming much more aware of the connection between how I nourished my body and how I performed. And so, I started to take on some eating behaviors that I felt were more beneficial to my performance. One was just eating-- I started to eat less meat, believe it or not, and more plant-based foods. That seemed to help, but I don't know if it was truly that beneficial for me. So, when I did return back to college and university, I became a vegetarian, because I started reading the scientific literature. This was back in the early 1980s, mid 1980s. Most of the science back then published research on vegetarians showed that they weighed less, they had less risk for cardiovascular and metabolic disease, heart disease, and diabetes. And so, I said, "Yeah, this could be the way to do it."

So, by the time I graduated and started graduate school, I asked my professor at the time, my advisor, "Could I test vegetarians and to see what their metabolism was like, because it seemed to influence so much of their health?" That's what I did. I conducted my first study at Purdue University with Seventh-day Adventist, because they follow a very, somewhat, strict vegetarian diet. Because I was a vegetarian, I could relate to them. What I found from that study was fascinating. I fed both vegetarians, myself included, and non-vegetarians, a standardized meal. It was a liquid protein meal at the time. It was a company called Sustacal, and it was one of those just meal replacements that they used primarily in the healthcare setting, hospital setting for patients that needed high-quality nutrition. So, it wasn't the best in terms of high quality, but it had some protein. 

What I found was very interesting. It was a dairy, animal-based protein. I wasn't paying attention to that necessarily. But what we found was that when the group of vegetarians, myself included, consumed that meal with slightly higher protein than a typical normal meal would have, they hung on to those calories, and they had a significantly lower postprandial thermogenic response. That's a fancy word for-- We burned less calories after we ate that meal. It was the same relative amount. So, everyone got the same relative amount based on their body weight. So, there was no difference in the quantity that people were consuming. Whereas when the omnivores consumed the meal, they were burning those calories much less efficiently. They were just expending. They had a much higher metabolic rate. So, it contradicted what our hypothesis was. We thought that, "Okay, these vegetarians weigh less, maybe they burn more calories after they eat." In fact, we found the opposite, they were actually burning much less.

So, what was the reason for that? What we ended up finding, based on some of the other data that we collected was probably due to them not being accustomed to consuming that much protein at a serving. And so, the body sensed this higher amount of protein in this meal challenge we gave them as a vegetarian and it decided to hold on to those calories, because it knew it was a very vital nutrient. We know that protein in Greek stands for proteios, means primary, vital. And so, as it turns out, because vegetarians in general consume less protein, especially high-quality protein, when they are faced with a meal that contains more protein and higher-quality protein, their body makes the decision to hold on to those calories, and not burn them, and to preserve those. And so, that was my first eye opening research experience early on in my career where I found that, "Wow, the quality of what we consume makes all the difference in the world." 

In fact, much less of our health is determined by controlling or managing the total number of calories we consume. The vast majority of our health and our physical performance, cognitive is determined by the quality of the nutrients. That was, again, way before many people were paying attention to this concept of nutrient density and the quality of the food that we consume. Most people still are focusing on the quantity and working off that outdated energy in, energy out or calories in, calories out energy balance formula. It's just simply outdated and has been proven time and time again not to be the most important way of looking at nutrition. So, yeah, that was my intro. 

Melanie Avalon: Wow. Okay, that's fascinating. Can I ask you some questions about that study? 

Paul J. Arciero: Sure. 

Melanie Avalon: So, how long was it? How many days? 

Paul J. Arciero: That was what was so powerful. This was just an acute meal challenge. So, it was just a single meal challenge that we were providing to these vegetarians-- We called nonvegetarians, omnivores. So, we had them come in, measure their baseline metabolism, so we had an understanding of what their resting metabolism was, and then we fed them the meal challenge, and then we measured their metabolism and their thermic response for three hours after along with hormones. So, we measured their thyroid hormones, insulin, glucose. So, yeah, it was a fun study to be a part of. 

Melanie Avalon: So, do you have any idea since then? Have you learned how long it would take them to adapt or habituate? Do you think if they had another meal, it would have the same effect? 

Paul J. Arciero: Yeah, that's an interesting question. I'm not aware of too many other studies that have converted [chuckles] vegetarians during a study into becoming an omnivore. It's hard to do. It's hard to break that. So, I'm not aware. I think it's a fairly acute response. I think the habituation from that or the acclimatizing to that higher-quality protein, it probably occurs-- Obviously, it occurs acutely, so very quickly that the body begins to hold on to those amino acids, because they realize how precious they are. And then how long does it take before? Maybe the body becomes, and I caution to use this word, but desensitized to it or maybe feels like, "Well, we've got sufficient amino acids now. We don't need to necessarily conserve those at the same level as what we were." 

I don't know how long that would take. Yeah, it really depends on the person, their activity level, because your activity is going to determine the degree to which your body holds on and utilizes, makes bioavailable, those amino acids for recovery and muscle protein synthesis. So, I think a lot of it would have to do with how active the person is at the time that they're making that transition. But the good news is, I guess, I go back to the bottom-line takeaway of the good news is that our body is very responsive. And that if we are eating poorly, or perhaps not to the level that the body optimally needs nutrients, once it's exposed and once it has an opportunity to benefit from a high-quality nourishing meal, the body can respond very quickly. That's what we took away, that the body is extremely responsive to consuming high-quality nourishment, even if a person has not been eating really well for a period of time.

Melanie Avalon: I think when people hear protein, they don't think it can be stored per se. So, when you say stored, was it storing the amino acids in the muscles? How does it store that protein?

Paul J. Arciero: Yeah, so storage is probably not the ideal word, but I would use the word, the bioavailable, the net utilization of the amino acids just become more available into the amino acid pool. So, when we eat those high-quality sources of protein, when the body begins the process of breaking that protein down and making those amino acids available to the body, they're incorporated into the cells to allow for the various pathways and functions that protein provides, which is abundant. We have so many different uses of amino acids inside of our body, making enzymes, making body tissues, hormones, structures, and immune cells. So, I think that's what the protein was being utilized for, as opposed to perhaps being oxidized and not utilized as efficiently. 

Melanie Avalon: Maybe this actually ties in really well to a similar concept, because that would be the concept of two populations receiving historically more protein or less protein. What about for people, because you have this protein pacing idea. What about the timing of protein? So, if you are having protein throughout the day, does that change the body's thermogenic or metabolic response to it compared to, if you're having it in concentrated meals or doing it with fasting, for example, and having all your protein at once, how does that affect the body's thermogenic and metabolic response? 

Paul J. Arciero: So, there's some good data coming out of some of the labs around the world. I can think of two offhand in Canada, one, McMaster, and then some of the other work that's been done here in the States. What they've shown is that, when they provide protein in various manners and they've looked at it as a bolus feeding, so two larger feedings of protein versus providing it in a more concentrated form, but distributed more evenly throughout the day, they did a bolus of two challenges of protein. So, they gave the same amount of protein over the course of the day, and they either delivered it in two, four, or eight feedings. I think those are the numbers that they used. What they found was that there seems to be an optimal amount. So, in terms of the timing that you're describing, when it's administered in a way that body can optimally digest it, absorb it, transport it, metabolize, store and utilize, it seems to be in this feeding of roughly 4 hours apart. And so, that would be a recommendation for people to try to see if they can optimize during a feeding day if they're not undergoing a fasting to try to optimize their protein intake. 

This is what we follow in our lab. We follow this protein pacing schedule of about every three and a half hours, but more optimally every four hours. That seems to be an ideal time where the body has sufficient focus of digesting and absorbing the amino acids from the protein, as opposed to concentrating it into this much more larger amount of protein, it's just harder for the body to digest it. So, that's what we know about-- And protein synthesis goes up. So, if you're looking at one of the functions of protein in the body, it is to increase tissue repair, tissue growth. So, we call that protein synthesis. What we found is, when you administer the protein in that more pacing approach, four hours, the body just seems to be more ideal at absorbing it. So, that's an important take home for people to consume that protein. 

We know that following an overnight fast, the body is starting to transition into a greater protein breakdown state. So, there's always the balance. When we talk about, at least from the muscle standpoint, muscle protein balance, the body is always trying to maintain, in an ideal world, a state of muscle protein synthesis. So, always having slightly more recovery, tissue repair, and growth than we are having breakdown, because we know that as we age, breakdown of our body protein stores is occurring at an accelerated rate, we have a blunting of our body's ability to build new protein and repair. And so, in the morning, we're in a slightly higher muscle protein breakdown state. That's why it's so important to start the day with a high-quality serving of protein, especially on a day that you're coming off, for example, an intermittent fast. We can talk maybe more about what that means. But when we undergo an intermittent fast, our body is undergoing some really favorable cellular changes. And one of those is preparing the body for the reentry of high-quality nourishment. 

So, we're actually creating an environment during an intermittent fast, where the body wants to supercharge its protein synthesis. I know that sounds a little bit unusual. Most people, when they think of an intermittent fast, the body is breaking itself down, it's removing old unwanted tissue and cells, it's undergoing this process of autophagy, kind of the house cleaning. And so, there's some really beneficial cellular responses. One of them is preparing the body to optimize protein synthesis. So, there's an ideal window of time that when you are coming off of an intermittent fast, when you provide the first reentry of high-quality nourishment, it should be amino acids. It should be protein. The highest quality protein that you can try to get your hands on, because that's going to be put to really good use in the body when we combine intermittent fasting with protein pacing in that way. 

So, the goal is to, every four hours, have that high-quality feeding throughout the day on a normal feeding day, that's the ideal. And then when a person has intermittent fasted, however long they decide to do it, it could be a 16-hour window, some do with the 16:8 method, some do a 24-hour intermittent fast, some extend it a little bit longer. The important point here is that, when you do break that fast, you want the highest quality protein that you can consume. 

Vanessa Spina: I was really glad that you brought up the pacing period of three hours to four hours, because that's just a question that we get so much. We were actually talking about it last night when we were recording, and we're well aware that there's anabolic window about 24 hours for people who are not professional athletes. But people are often curious like, you know, what that amount of time is. So, I'm really glad that you brought that up and clarified it. I really want to try the protein pacing approach. I'm planning on trying it as an experiment later this summer to do this. Having the high-quality protein every three hours to four hours throughout my eating window, and seeing what happens with it, and doing some body composition before and after. So, it'll be interesting to see if it makes a difference. 

Melanie Avalon: Yeah, and then something else I wanted to comment on. A lot of people often say that it's not good to eat multiple hours before bed. But in your protein pacing approach, you actually do recommend eating two hours before bed, is that correct? 

Paul J. Arciero: That is correct. Yeah, that's so controversial. 

Melanie Avalon: Yeah. [laughs] Would you like to expand on that? 

Paul J. Arciero: Yeah. So, is breakfast as not being one of the most important meals of the day? Then we can maybe talk about that, but the nighttime feeding is actually crucial. There's such a difference. I think that people need to understand that, again, it's less about the quantity, although that's important, you don't want to over consume later on the day. We call it the back end of eating, you want to do more front loading of your calories if possible. But definitely for athletes and people that have had more of a challenging window during the day to consume the nutrients. So often, people either get busy or they make the conscious decision to not eat too much during the day, and then unfortunately at night, sometimes, the floodgates open and they end up over consuming. Those two overconsumed nutrients are oftentimes simple carbohydrates and some fat. And so, that combination is not ideal. 

So, at night, when you are trying to replenish the body with optimal nourishment, carbohydrates and fats together are not the ideal combination. We have lots of scientific proof to show that those two things are going to very, very quickly favor energy storage inside your body. Unfortunately, not in the form of healthy lean muscle mass, which is what the goal is during that overnight time period, because you have a hormonal environment that is very favorable to allowing the body to recover, repair, and rejuvenate during those nighttime hours. You want to provide the optimal nourishment and that comes in the form of amino acids of high-quality protein. 

So, yeah, that two-hour eating window, before you go to bed, it does not have to be high calorie. It should optimally be high-quality protein, and then perhaps a little bit of healthy fat, because that will help keep the insulin level down, a little bit lower than it would be if you were to consume protein and a more simple carb or some optimal high-quality protein and some complex carbohydrates, that combination or a combination of all three, but definitely the protein. The amount seems to be somewhere between 20 g to 40 g. So, people often ask, "Oh, that seems like so much. How many calories is that?" Well, it's going to be somewhere between 80 calories and 160 calories of protein. Now, 40 does seem like a lot, but again, if you're a really intense high energy output athlete, that's not that much for those types of individuals that need to replenish, and rebuild, and restore muscle tissue, but somewhere within that range of 20 to 40 g of protein. 

And then, like I said, the balance of the remaining calories could be in the form of healthy fat, whether it's avocado or nuts and seeds. Those would be some of the foods. And then some fresh fruit, perhaps blueberries, somewhat on the lower sugar side, but high antioxidant because of the favorable anti-inflammatory benefits you'll get from dark colored fruits. That could beneficial as well. So, that would be the recommendation. Yeah, that's actually a really important feeding, because not catching that window or benefiting from that feeding window at night for certain people. Here's what's interesting, Vanessa and Melanie. When we make this recommendation to people who want weight loss, that's one of the most important feedings that they end up doing. I know it sounds contrary, but yeah, for weight loss and for muscle mass maintenance and growth, that feeding is equally important for both of those groups. They're actually on opposite ends of the spectrum. 

You have one group that's excess body weight and body fat and they're having that high-quality protein just before bed and benefiting from it tremendously. The data that we have from our lab that we incorporate that as really a required component to their nutrition, dietary regimen is a game changer in terms of the benefit that they have in their body composition, in terms of muscle mass maintenance and fat loss that occurs. And then we know from an athletic standpoint, that's also extremely beneficial to helping increase muscle mass. 

Vanessa Spina: It's really, really interesting, because I've come across it before for athletes who are especially physique competitors to have a protein feed before bed helps with preventing any muscle protein breakdown at night. But most of the researchers that I've spoken to say, "You got to make sure to close that eating window as early in the day as possible, especially because of leptin docking around midnight. Like, you don't want to have high insulin competing with leptin." So, that's fascinating that that's what you found in your lab. 

Paul J. Arciero: [chuckles] Yes. But I think the key, and I'm glad you pointed it out, we try to minimize the insulin spike when we do deliver that protein. And so, with weight loss, we generally recommend the protein with a small fat combination, a fat feeding whether it's nuts or some coconut or avocado, something that again helps kind of counter that insulin release we have found beneficial. 

Melanie Avalon: And then, interestingly, to continue the controversy, it was so layered, because when it comes to the controversy with breakfast so, first of all, we have the very intense pro breakfast movement. Then we have the response, especially in the fasting community, trying to point out all of the potential issues with the breakfast funded studies. But then you point out the issues with the critique of pointing out the issues of the breakfast studies. So, where do you land on breakfast? 

Paul J. Arciero: Yeah, so during fasting, obviously, you are not providing any nourishment during that time period. But I think that has to be done very infrequently. And again, because we've already discussed that when you are waking up in the morning after a fast, your body's not in an ideal environment for protein synthesis. It's actually starting to transition into a greater state of protein breakdown. But you're having less protein synthesis is what essentially is happening. That's not ideal, particularly for weight loss. So, let's just talk about it for weight loss. So, we really recommend with our study participants that it's most important that you start the day as soon as possible upon waking with a high-quality serving of protein, combined again with very, very high-quality nourishment of lower glycemic index carbohydrates and healthy forms of fat coming in. 

But that is the ideal environment to transition immediately over into a greater state of protein synthesis. That's what's key, because they're doing it at the same time they're consuming less calories. So, they're on a lower calorie intake. But they need to safeguard against any further increase in muscle protein breakdown and decrease of muscle protein synthesis. So, that early morning feeding is paramount for them and for their success. It's actually essential for their satiation. Otherwise, they run the risk of becoming much too hungry, and making the wrong food choice. So, in our study participants, one of the main reasons we've had this success that we have is because we place such a very focused and heavy emphasis on that early morning feeding of high-quality protein. It's just absolutely essential. 

By the way, it's important to point out that much of our research we do when we're dealing with weight loss in people, we are controlling further exercise. So, some of our studies, not all of them, because we do place a heavy emphasis on the lifestyle approach incorporating exercise, as you know through the PRISE protocol that I created. But for many people, we actually much prefer that we monitor and control and limit their exercise, because that can increase feeding behaviors, and we really want to focus on their nutrition only. And so, we're making this recommendation for them to eat first thing in the morning knowing that we're not recommending that they engage in any level of strenuous exercise other than normal walking and things like that. 

So, yeah, that early morning feeding. And I think that's where the controversy has been, that much of the backlash against breakfast not being as beneficial or healthy or optimal for people's overall health is because they've missed the target. Again, they have not had their eye toward the nutrient that is the most essential and that's protein. They've just focused on a typical breakfast feeding, which is usually higher carbohydrate. And that's been why some of the data points to breakfast not being beneficial. And so, we deemphasize obviously the carbohydrate aspect and emphasize the protein. But yeah, it's super, super important. And it's particularly important that breakfast feeding after they come off, we do what's called a one day, 24-hour or two-day fast, 24, 48, it actually is a little bit longer than that in some cases, because we recommend on a one day that they hold off on that feeding that evening. 

So, if they've gone from stopping eating the day before, let's say at 8 o'clock, and then they fast the entire day the next day, instead of them resuming eating at 8 o'clock the next night, we will often have them abstain from consuming their first meal until the following morning. So, they're actually doing the equivalent of a 36-hour fast. And then the ones that are doing a two-day are actually extending it to the following morning of the following day. So, it would be a 60-hour fast, which is a little bit longer. We don't have them abstain completely as Vanessa and I talked about in our previous podcast. We have them consume a very high-quality nutrient dense, adaptogen, antioxidant beverages, and some collagen protein as well during the intermittent fast, but it's very, very low calorie. But it's administered again on that pacing schedule of every four hours. But it's very low nutrition, so it's only about 100 calories each of those feedings. So, over the course of a day, it's equivalent of about 400 calories, which is not a lot to trigger any significant disruption in the benefits of the fasting that we're having them do. 

So, yeah, I would say in conclusion, breakfast is super important whether you're looking to lose body fat and change your body composition favorably by losing body fat, particularly abdominal visceral fat, and maintaining and even increasing your lean body mass. And that goes hand in hand with the evening feeding as well. I think I shared that. Our 2013 Obesity Journal study showed that group of individuals, when they followed this protein pacing and calorie restricted regimen, they lost significant amounts of weight, but they actually were able to increase, although slightly but significantly, their lean body mass. So, yeah, it definitely makes a difference. 

Melanie Avalon: I have some questions about the fasting. Before that, I have one really random question that I have been thinking about for so long. I don't know, if you have any thoughts or know the answer to this. The autophagy that occurs during fasting, does it create any measurable amount of "protein that we could measure." For people who are fasting, do they maybe need slightly less protein in their eating window because they're freeing up amino acids from autophagy while fasting? 

Paul J. Arciero: I don't know if they would need less. It would make sense that during that process, the body is shuttling some amino acids into the free pool. But I don't know if less would be. So, when they resume feeding, is that what you're thinking? 

Melanie Avalon: So, compared to eating protein all throughout the day, compared to if you're fasting and you have autophagy, are you freeing up, recycling getting more aminos? 

Paul J. Arciero: Yeah, I would caution about over providing. So, you probably wouldn't need more during that fasting time period. We do provide a little bit during the actual fasting window, but like I said, in very small amounts. We don't do it at every one of the four feedings. We only do it at one, maybe two of them where we'll provide, have them consume a little bit of additional protein. Usually, like I said, in the form of collagen or bone broth is the form that we use. Yeah, I don't know how much difference it makes in their overall protein balance and protein synthesis. Maybe it just helps provide that little bit extra to allow for a halting of any additional amount of protein breakdown. 

Melanie Avalon: That's also what I would wonder about. Because I know a lot of our listeners and me included, do fast daily? So, I fast every day completely and then just eat in the evening. It works really well for me. I've been able to maintain and even build muscle doing that. Vanessa and I were talking about this yesterday. I'm like, "Well, when I get older, is it going to be a problem?" So, yeah, I'm very haunted by these questions. 

Paul J. Arciero: Yeah, no and they're really good ones to ask. Yeah, so, let me just ask I'm curious how many people turn around and ask the host's questions. But when you do your fast, are they more than a 16-hour? It sounds like it is, because you're only eating within a very small window. 

Melanie Avalon: I typically eat for about four hours or five hours in the evening. Very high protein, like pounds and pounds of protein and blueberries. [laughs] 

Paul J. Arciero: Yeah, that's great. It sounds like you're exercising, you're doing some resistance exercise. 

Melanie Avalon: Well, I wear weights during the day around. I do a lot of EMSculpt actually. Are you familiar with that? 

Paul J. Arciero: I've heard of it, but I'm not familiar with the specifics of it. 

Melanie Avalon: It's a machine that does tons of muscle contractions more than you could ever do consciously. 

Paul J. Arciero: So, a little bit like e-stim? 

Melanie Avalon: Yeah, I'm actually interviewing Terry Wahls this week as well. She talks about e-stim all the time. So, I've been looking at e-stim a lot. Yeah, similar to that. So, yes, I've been able to build muscle with that and fasting. I haven't broken my fasting pattern. Like I said, I do consume a very large amount of protein. So, with your fasting, because I know we're going to get a lot of questions about this, how do we know what enzymatic processes, and characteristics, and benefits of fasting apply to a person on a completely strict non-caloric fast compared to a fast where there is a small amount of calories? It sounds a little bit similar to Valter Longo's fasting mimicking diet. We've had him on the show a few times. Although your version-- because I was thinking about it. Because his version, the focus is low protein. That's the focus. Your version seems to sound like the focus is on higher protein, but low calorie, is that correct, while fasting?

Paul J. Arciero: You know what, it absolutely is. Yeah, Valter and David Sinclair, although he takes a slightly different approach with his fasting. Again, they're both lower protein. We just haven't found the same degree of success overall. Again, we're looking at it very broadly in the approach that we take with our model of intermittent fasting and protein pacing. We're not so concerned with-- I don't know, how do I want to say this without coming across as being too negative on their approach, but we're looking at it from an overall physical, cognitive and performance health outcome. And so, yeah, I think for body composition, we just believe-- Again, I could cite our last obesity study that you both had read, and Vanessa had come across and that you both had blogged about. That was a good example. 

We had two groups. One was not following the intermittent fasting, but they were calorically restricting, and it was with lower protein. They just did not have nearly the same benefit. So, from an overall perspective, from a body composition, hormonal, cardiovascular-- So, it's hard to justify the lowering of the protein during the normal dietary eating window, feeding window without being able to counterbalance that protein breakdown that would be occurring as you come off that fast. 

Melanie Avalon: So, here's a question, because I know Longo has said that, ideally people would just do a water fast, but he found it was too hard for people. So, that's why he created the fasting mimicking diet. It sounds like for you, although I'll ask you, if people did your approach with just water fasting, would you think that would have negative effects? 

Paul J. Arciero: Yeah, I do. I gave this analogy earlier that if it's only water, I struggle with that, just because I give the analogy that when we are undergoing a fast and it's only water, does it truly allow the body to counter the toxins, for example, that are being released because that's what's happening. Does it truly help facilitate and augment the old unwanted cells that the body is trying to dispose of and breakdown? Again, just speaking specific to our data, what we have found is that when you can help this autophagy, and mitophagy, and the whole process that's occurring during that fast, and as much as possible help support the protein synthesis that you want to optimize coming off of the fast, providing the body some additional support with the antioxidants and some of the adaptogens. 

I know Sinclair talks about this a lot in his research, being able to provide some of these nutrients that the body definitely benefits from a gene expression standpoint and at an enzyme level as well that it just seems that during that intermittent fasting period, especially the longer you go with it. So, I guess, if it was a shorter window, maybe less than 20 hours, 18 hours. Some of the Mattson's work and de Cabo. If it's less than that time period and you're not quite into that ketosis state and water perhaps is sufficient. But I think if you're extending beyond that, and that's the model that we use, again, as I mentioned, our fasting window is longer. I think having those additional very low calorie but very nutrient dense antioxidants and adaptogens, I think, play a critical role in helping the body facilitate that process of autophagy and helping for the removal of some of those things, some of those toxic substances. 

Melanie Avalon: Have you tested just the noncaloric antioxidant supplementation or is it always with the snacking aspect as well? 

Paul J. Arciero: So, we've only used a caloric restriction model. So, where they're just paying attention to a daily caloric restriction and then this nutritionally fasted intermittent fast. Yeah, so, we will support it with these. Yeah, I hesitate to use the word snacking, although--

Melanie Avalon: [laughs] 

Paul J. Arciero: No, it is right, because they are consuming that very small amount. In some cases, those adaptogens and antioxidants that they're consuming, it's not quite even 100 calories. In some cases, for some of them, it's down as low as 20 calories to 40 calories over a four-hour window. So, that's really negligible. But yeah, it's not standard across the board that they're all taking in 100 calories at each of those feedings every four hours. In some cases, it's as low as 20 calories to 40 calories. But yeah, no, that's a really good point. Doing that comparison where we're having that intermittent fast and matching calories over the course of a full day, I think would be a next study to clearly delineate what is the difference in terms of the body composition changes, the hormonal, metabolic, cardiovascular, even some of the mood state benefits that we have shown as well to a complete water noncaloric fast to this very low calorie, nutritionally supported fast. 

Melanie Avalon: It would be awesome to see that for two camps, like, people who are doing fasting less, like you were saying, maybe 18 hours or 20 hours and then the extended version. That would be exciting. 

Paul J. Arciero: It would be. Because again, there're two camps on that. If you look at some of the-- I know Mattson and de Cabo, they speak to that longer fast period as being beneficial and others do as well, and others have found success with the shorter window. 

Melanie Avalon: Is there the potential that exogenous antioxidants would downregulate the body's endogenous antioxidant production? 

Paul J. Arciero: Yeah, I do. And we have evidence to support that. At those higher concentrated amounts, there very likely would-be a downregulation of the body's endogenous. But I think, again, although we're providing this nutrient dense source of these antioxidants and adaptogens, they're far below what you would find in a normal supplemented antioxidant product where it's more of a daily serving. So, when you think about some of the antioxidants that are commercially available and sold, they're usually in these very highly concentrated sources that you would take once during the day or maybe twice. But they would be very, very concentrated to allow for that absorption to occur over the course of a day. Whereas what we're providing in this liquid form is much more diluted and not nearly at the same concentration level. So, again, unlikely that it would create that downregulation that it would normally occur that we find when people are supplementing with those much higher concentrations. 

Melanie Avalon: Awesome, because I feel like we dove straight deep into the details, and Vanessa and I have talked about this so much that I forget that a lot of the listeners, this is their first-time hearing about this study. So, just to recap the findings of the study, what were the actual findings with-- You already said this, but I just want to draw more attention to it, with the weight loss, was it around the same calories that both groups ate? 

Paul J. Arciero: Yes. So, great question. In our most recent publication, we provided, on average, the women about 1,200 calories over the course of a week-- Sorry, over the course of a day, although that changed slightly depending upon whether they were intermittent fasting for one day or two days, and the caloric restriction group, the same. They were consuming, the women about 1,200 calories, men we bumped up a little bit higher. And again, it was based on body weight differences between the men and the women. Men were at about 1,500 calories. Again, I'm so glad you asked that question, because it's a really important one to focus on, despite having identical calorie intakes over the course of the measurement period. In fact, I'm looking at the data right here. The energy intake was actually slightly higher in the intermittent fasting groups compared to the caloric restriction groups. So, that's telling that here they were consuming even slightly more calories, but they ended up losing significantly more body weight, significantly more fat weight. They reduced their waist circumference significantly more. 

So, yeah, despite having slightly higher intakes, the intermittent fasting protein pacing groups lost more weight, lost more body fat, more visceral fat. They were able to maintain their lean body mass to a greater degree than the caloric restriction group. So, I don't think there's any controversy or disagreement that all calories are not the same, obviously. And even how we consume them makes a big difference, because our data shows very convincingly that when these two groups of people were able to change it up, it was almost a doubling of weight loss, a doubling of body fat, a doubling of visceral fat. They had a significant reduction in their desire to eat that dropped significantly. So, yeah, those are really important takeaways.

Vanessa Spina: I love that you recapped the findings on the study for everyone, for listeners, who haven't been talking about it as much as you and I have. It's really, really helpful. And I know that it was intentional that the calories would be equated, but it really stood out to me that the one group ended up eating more and still losing more, which is one of the amazing features of intermittent fasting.

Melanie Avalon: Definitely. Okay, some other really quick rabbit hole tangent questions from some of your other studies or actually in your book as well. I was wondering if you could talk very briefly. There's something that Vanessa and I are a little bit fans of and that's being smart and using caffeine to your advantage. You had a cool section in your book on your thoughts on caffeine. What are your thoughts on caffeine? 

Paul J. Arciero: [laughs] Yeah, so that was an interesting one too. But early on in my career, I was not a caffeine drinker and I had read a lot about the benefits of caffeine. Sometimes, the not so benefits, sometimes the detriments of caffeine. So, we don't necessarily control it to any great degree although we do control. We do ask them to report caffeine intake. It is a very powerful central nervous system and peripheral nervous system stimulant. So, it activates our central nervous system and our peripheral nervous system in the sense that from a metabolic standpoint, it increases the release of stored body fat. We call that lipolysis. So, it just breaks down our lipid stores, which are our body fat stores into our bloodstream. It makes the fatty acids, that's the equivalent of amino acids to protein, fatty acids to fat. It makes these subunits of our lipid stores available to cells to use as energy to burn. So, caffeine, to a very large degree, helps mobilize our body fat stores.

Here's where it gets a little bit interesting. When you consume caffeine, there are some differences between old and young people. And so, I was able to study that extensively early on in my career, and I was able to show that younger, more fit, and active people have an easier ability to mobilize their stored body fat into their bloodstream to be accessed and used as an energy source in their cells, primarily their muscle cells. Whereas we get older, we lose that ability with one caveat, the more active we stay, the more fit we stay. So, here's a plug for--

I know we haven't talked much about exercise or physical activity, but the more we can engage our body in movement as we're drinking this caffeine, especially as we get older, the more likely we are to maintain the benefits of the caffeine to release it from our fat stores. That's a really good indication of health. Our body's ability to release fat from its storage depot is an indication of health. We want to be able to do that. It's when we have become resistant to mobilizing our body fat into our blood to be circulating it to the muscle cells and other cells that would break it down and use it as an energy source is a sign of disease. And so, caffeine is really helpful for some people.

I'm not a caffeine drinker, although I understand the benefits from it. So, what we do in our research in our lab is we encourage a very strategic application of caffeine intake. We recommend that people consume it earlier on in the day is the ideal time to do it. If you are someone who does drink caffeine or consume caffeine, because then you will benefit from the rest of the day being active, and moving, and allowing for your body to use that storage release of fat into the body. So, earlier in the day, caffeine is ideal for people. It has some proven health benefits. We know that caffeine has some antioxidants or at least coffee does and tea that contain caffeine, chocolate, dark chocolate especially, 70% or more above of cacao. So, you have the added benefit of the caffeine in those products of coffee, tea, and chocolate providing some benefit to release the fat into the blood to be used as energy, and then also to provide some additional antioxidants-- naturally occurring antioxidants and levels that the body can benefit from. 

So, yeah, I'm favorable to it, especially if people can tolerate it, but it's not for everybody. Sometimes, people are sensitive to the caffeine in terms of heart palpitations, irritability, insomnia, which happen also to be the same things that people experience when they have withdrawal from caffeine. So, it can be a double-edged sword. But I think for a lot of people who can tolerate it and enjoy it, just making sure that they're consuming it earlier on in the day is ideal, so that it doesn't interfere with resting and sleep.

Melanie Avalon: Awesome. Yeah, I think because when it comes to the whole caffeine world or even fat burner supplement world, which a lot of those are really crazy, and I wouldn't put them in my mouth, but I think people see it and they think, "Oh, well, there's no magic pill to burn fat," which is true. But if there are compounds which unlock the ability to burn fat, I think that's huge. So, being smart about it sounds like the way to go. 

Paul J. Arciero: Yeah, I think we definitely don't have an underemphasis on caffeine. We have plenty of it available at our disposal anytime we want. So, yeah, if anything we have to be a little bit more cautious about overconsuming it. So, yeah, that equivalent of one cup to two cups a day is a safe recommendation as long as it's done earlier on in the day, it can be of benefit to people.

Melanie Avalon: Okay. And then another question I'm dying to ask you. You have a fascinating study. I know I had the title here, but it was looking at thermogenic response to a processed type of diet, but a nutritionally rich one compared to whole foods and actually finding a higher thermogenic effect with the supplemental form. What were your findings with that? That was really surprising to me.

Paul J. Arciero: That was. That was a fascinating study. I think if it was the one that you're referring to, it's the postprandial thermic response to unprocessed whole food meal.

Melanie Avalon: Oh, I found it. Yeah, Lower Postprandial Thermogenic Response to an Unprocessed Whole Food Meal Compared to an Iso-Energetic/Macronutrient Meal Replacement in Young Women, August 2020. 

Paul J. Arciero: Yeah. This was a really interesting study. We wanted to see-- We fed these two different breakfast meals. So, there's a lot of controversy over meal replacements. We wanted to somewhat dispel that because there's different processing that takes place with more traditional processed foods that are highly refined and not necessarily nutritionally engineered. They're looking to provide palatable food, high simple sugars, high refined carbohydrate, not very healthy from a perspective of nourishment, nutrient density. And so, we sought to change that. What we did was we took a group of women, we fed them two identical meals, so they ate pretty much the same thing, about half the number of calories in the meal, about 500 calories with carbohydrates, 26% fat, 24% protein. So, it was a relatively balanced if you want to use that much carbohydrate. We generally don't recommend carbohydrate intake that high. We're more on the side of a lower carbohydrate. Not quite to the level of ketogenic, but in some cases, we advocate for a much higher fat ratio compared to that level. But we were providing more of a typical meal.

And so, we gave a whole food meal or a meal replacement. What we found, given the same number of calories, same macronutrient distribution, the meal replacement, what we call nutritionally engineered meal, resulted in a much higher thermic response. So, they burned much more of their calories similar to what we found, actually interestingly enough with the vegetarian study that I described at the beginning. And so, this meal replacement just jacked up their calorie expenditure, energy expenditure, almost double compared to the group that was eating the whole food meal.

So, it's one of those conclusions and I have to be careful because I am a strong whole food proponent that I think sometimes we compartmentalize nutritionally engineered foods as being bad because they're processed. We can drink them out of a powdered container or already ready to drink mixed meal. I'm not saying all of them are necessarily good or bad, but some of them clearly can provide a nutritious meal replacement, especially if they have been formulated in a really smart way and beneficial way in terms of the ingredients that they use. And so, yeah, I think it was just important to highlight that.

Melanie Avalon: I had never seen that before. All the studies I had read before on that topic were finding the opposite. But like you said, I guess, there's a key difference in the formulation of those products. 

Paul J. Arciero: They do range. And that happened despite any differences in hunger, satiety, blood glucose. So, that was interesting. 

Melanie Avalon: What were you expecting to find? 

Paul J. Arciero: Yeah. Because of the composition of the meal, one obviously being a liquid and the other one being a whole food, yeah, I think we were thinking that there might be a difference in the blood glucose response, the satiety, because of, again, the administration of how the meal was provided. And so, that was a little bit in opposition of what we were thinking, that this liquid meal based on what most people would think, you would have this very high, perhaps, maybe glucose response, maybe the body wouldn't undergo as much digestion because it's already in a liquid form. And so, the fact that we found this higher thermic response was unusual. 

Melanie Avalon: Maybe one last thing we could touch on, because I think it was the most recent publication I could find from you, but it was an editorial. How does exercise modify the course of Alzheimer's disease? It was really, really fascinating. But one thing I wanted to ask you about specifically was, you actually had a paragraph about the role of leptin in Alzheimer's. I was wondering what your thoughts are on that because leptin is a hormone that we talk about a lot on this show and how it's affected by things like diet and fasting and all the things. So, do you have thoughts on that? 

Paul J. Arciero: Yeah. Well, as I say in that editorial, that's interesting that you found that one. That's been a hot topic for people lately, because leptin has those dual roles inside the body in one way. I don't know how you've talked about it on your podcast, but it's similar in how our body also deals with insulin. Insulin is obviously extremely important as is leptin in helping regulate our blood sugar insulin, leptin helping regulate our energy stores and our arcuate nucleus, and hypothalamus in terms of feeding and sending signals to the brain in terms of feeding and satiety. But I think it can get out of whack and we can become obviously leptin resistant. But we also know that, when leptin does get up too high, it has that inflammatory response. And so, we just have to be careful about that. 

So, I talk about how leptin serves this dual role as this hormone in terms of how it helps mediate and regulate various endocrine and metabolic pathways, particularly around our energy storage. And then it's also a cytokine, which augments this inflammatory role. And so, we've shown, at least for as we age, and I'm talking about as we get into older age, lower leptin concentrations are actually associated with this increased risk in progression of Alzheimer's disease and related dementias. So, as much as we want to regulate leptin, if it gets too low, that's not healthy. But we know that when we have leptin out of control and it gets too high, it can become very pro-inflammatory and that's not beneficial. 

So, we need to, again, undergo lifestyle strategies that provide the crosstalk between our energy stores, our body energy stores, particularly our adipose tissue and our central nervous system in a way that the communication is uninhibited. It's very sensitized. It's occurring in a very fluid, harmonic way. I think we do so many things to disrupt that communication signaling. We oftentimes have leptin circulating at too high levels, much like we do insulin. When leptin is circulating excessively, as it is too often in too many people, we just lose that sensitivity. We lose that communication pathway operating at the level that it should. We know that that creates a very pro-inflammatory state. It's not good for the brain. It's not good for the blood vessels of the body. It's not good for anything in the body. 

So, what we have shown is that when our study participants undergo protein pacing and intermittent fasting, their leptin levels drop drastically from the very excessive levels that they're at. That's a very favorable response. It's not like they're dropping into these very dangerous low levels, where it would be implicated, perhaps, in this progression that we talked about with Alzheimer's when levels get too low. But a lot of times, that's associated with low energy stores when people are malnourished. So, there're other factors going on when that leptin gets down that too low. But if we can keep leptin communicating with the brain at a level that's manageable within the blood, so that it's not creating this pro-inflammatory state, it's not being dysregulated in its communication pathway with the brain, it's actually serving an instrumental role.

So, the good news is that we were able to document this really significant drop. In fact, in one of the studies that I sent to both of you, one of our first intermittent fasting protein pacing papers, we showed a 70% drop in leptin. And that was despite having other very favorable changes in the inflammatory state of the participants and cardiovascularly, the cardiovascular system improved drastically. We had much greater return times. We had very favorable changes in pulse wave velocity and augmentation index. So, we demonstrated that the arteries, the blood vessels, the vessels that manage our blood flow coming from the heart, all changed in a really favorable way. They got much more elastic and responsive at the same time these changes were happening in leptin. 

So, yeah, leptin is a powerful, powerful hormone and plays a critical role in so many areas of the body. I think we just sometimes assume that it's only regulating our energy stores. That's not true. It's super important in general inflammation in our periphery, but also cognitively central nervous system wise. 

Vanessa Spina: Just to circle back to the beginning, I know that one of the strategies for lowering leptin levels when they're too high is having a protein prioritized breakfast. So, I love that we can circle back to that. Now, one thing I wanted to make sure that we did touch on with you, when you were on the Optimal Protein podcast, you mentioned that you have an incredible amount of data that you collected on the gut microbiome. I wanted to make sure that we got to chat about that a little bit. That's definitely a topic that our listeners, and Melanie, and myself are fascinated by as well. 

Paul J. Arciero: Vanessa, thanks for pointing that out. We have so much great data. I'm sorry that I can't share it all with you. Ah, it's heartbreaking. What we do know is that we've had some extremely favorable changes in the gut microbiome when people follow the intermittent fasting protein pacing compared to the calorie restriction. I know without having the no calorie--noncaloric fasting, we can't talk about that. I think that's a great next study. But at least from our model of the intermittent nutritional fasting and protein pacing compared to the caloric restriction, the diversity of the gut microbiome has changed extremely favorably. And that data will hopefully be coming out very soon. But I can just put that statement out that we have some very favorable changes. 

The other thing that sometimes is not as emphasized, and I think we touched on this very briefly. But the self-reported gut, we call it the gut disturbance index. When people comment on their gut health just based on how they feel, "Oh, I have stomach issues. Oh, my stomach doesn't deal well when I eat that, or I'm having some GI upset and disturbance," people talk about it and refer to it a lot. But actually, being able to document this, there's not a lot of data right now that's out there that is examining how different dietary regimens impact our GI, at least in this case, the self-reported GI disturbance. What we were able to show in as little as four weeks and here's what I'm bringing this up for is because in as little as four weeks, we can manifest significant improvement in the GI response that people feel. We were able to show that in the four-week study that we published in the Frontiers in Nutrition, we were able to show gastrointestinal symptoms reduced significantly in people that were following a two-day intermittent fast compared to a one day. So, there's a little plug for people that do want to experiment with fasting a little bit longer. And that makes, I guess, sense too, because you're giving the gut a little bit of a longer time to rest. 

Yes, but when we compared it to the group that was calorically restricting, so they were reducing their intake as well. As I already mentioned, they actually, over the course of the study period, were actually consuming slightly less on a weekly basis than the other group. We again showed that GI disturbance went down significantly in the intermittent fasting group, even though they were consuming slightly more calories over the course of a week. So, there was something really staying with that intermittent fasting. Something was really happening over the long haul in affecting a positive change in their GI disturbance symptoms. So, that's worth noting. There's something very unique and beneficial, not just happening within the gut microbiome that's changing very favorable with the diversity of the gut microbiome. So, the microflora, the different genus strains and things like that that were occurring. It was improving significantly. But the actual symptoms that people experienced were reducing significantly. So, yeah, another massive and I hope really valuable and important piece of scientific proof that, yeah, this intermittent fasting is real, and it definitely helps both within and in our heads in terms of symptoms. 

Melanie Avalon: That's really exciting. Do you know when you'll be publishing that work? 

Paul J. Arciero: Well, it's in the pipeline. And so, we haven't officially received an acceptance yet for it. So, we have to hold off until we get that. I'm hoping maybe, let's see, we're in June. This fall and I would be great to circle back with you and share that with you. 

Melanie Avalon: Awesome. Yeah, we'll have to have you back and talk about that, and maybe have some listener Q&A specifically for you if you're open to it. That'd be amazing. 

Paul J. Arciero: Yeah, sure. 

Melanie Avalon: Awesome. Well, this has been absolutely so amazing. I know, Vanessa and I both were just so grateful for everything that you are doing. You're just doing so much incredible work about topics that we personally are obsessed with, but that we see affecting so many people's lives. I really, really appreciate the humanity that you bring to all of it. You've just made it so approachable and understandable. Like I said, for listeners, definitely check out Dr. Arciero's books, because they are fascinating and also super motivational. They're very empowering. So, we just really can't thank you enough for everything that you're doing. 

Paul J. Arciero: Thank you both for having me. And thank you for the work that you're doing. Melanie. I'm really grateful that you provide this platform to share this information with people. So, thanks for having me. 

Melanie Avalon: Awesome. Well-- 

Vanessa Spina: It was really wonderful to get to have this follow-up discussion with you. 

Melanie Avalon: Yes, it was amazing. I would love to have a debate episode, have you and David Sinclair. You and Valter Longo. 

Paul J. Arciero: Yeah. Have you had David on? 

Melanie Avalon: Mm-hmm. Yeah, on my other show, a few times. Yeah, I just love all the different perspectives. So, it's really exciting to see your version, which is very similar in a way to their work, but the focus on the protein in a way, so completely opposite. At the same time, very, very exciting. 

Paul J. Arciero: Well, I'll just make one comment on that and you can take it or leave it. But I think using humans in their natural living environment is really important, and their work that they're doing is amazing. It's cutting edge, it's providing incredible change, and it's revolutionary and innovative. But yeah, I'm hoping that there's some type of mutual coming together on this, because I think that in the perspective of the human model, living and engaging with the world in an active, dynamic, physical way where we know that these different modes of exercise play such a critical role in helping provide health, and cognitive, and performance benefit. I think to just, for example, recommend one type of exercise, high intensity exercise is the only means to provide health is a little bit short sighted. 

To suggest that given protein's role in cancer, in certain cancer growth, yeah, I think we just need to continue to be open minded and look at it from the perspective of the free living out in the wild human in which we study and showing the benefits that are derived from this healthy amount of protein dispersed evenly over the course of a day. So far anyway is proven to win the day. And so, yeah, hopefully, we can make that fine tuning of recommendation. 

Melanie Avalon: I could not agree more. I'm haunted by the question of longevity, and so then I'm definitely haunted by this low protein research versus real life application. Intuitively, I just feel like protein is not life, but it feels very crucial. 

Paul J. Arciero: Well said. No, very well said. Yeah, I think that I hope comes to the surface with all of their work eventually here. But thank you, again, both of you for doing what you do and thank you for having me on and highlighting this research. 

Melanie Avalon: Awesome. Well, thank you. Enjoy the rest of your day, and we will hopefully talk to you soon. 

Paul J. Arciero: Love to hear it when you're finished with it. 

Melanie Avalon: Oh, yes. We'll send it to you, for sure. 

Paul J. Arciero: Have a great day. 

Melanie Avalon: Thanks. 

Vanessa Spina: Thank you, Paul. 

Melanie Avalon: Thank you so much for listening to the Intermittent Fasting Podcast. Please remember everything we discussed on this show does not constitute medical advice and no patient-doctor relationship is formed. If you enjoyed the show, please consider writing a review on iTunes. We couldn't do this without our amazing team, administration by Sharon Merriman, editing by Podcast Doctors, show notes and artwork by Brianna Joyner, transcripts by SpeechDocs, and original theme composed by Leland Cox and re-composed by Steve Saunders. See you next week.

[Transcript provided by SpeechDocs Podcast Transcription]


Check out the Stuff We Like page for links to any of the books/supplements/products etc. mentioned on the podcast that we like!

More on Vanessa: ketogenicgirl.com

Theme Music Composed By Leland Cox: LelandCox.com

If you enjoyed this episode, please consider leaving us a review in Apple Podcasts - it helps more than you know!