Recently, I interviewed Dr. David Jockers, and we talked about a comprehensive chat about fasting and its impact on thyroid health. If you would prefer to listen to the interview you can access it by Clicking Here [1].
Dr. Eric Osansky:
I am super excited to chat with Dr. David Jockers, as we are going to be talking about fasting. Let me go ahead and dive into Dr. Jockers’ impressive bio here: Dr. David Jockers is a doctor of natural medicine who specializes in functional nutrition and natural health strategies. He is the founder of DrJockers.com, a website designed to empower people with science-based solutions to improve their health. DrJockers.com has gotten over one million monthly page views and is considered one of the most well-researched and easy-to-read health websites in the world.
Dr. Jockers’ work has been published in various popular media outlets, including ABC, Fox News, The Hallmark Channel, Home & Family, and The Dr. Oz Show. Dr. Jockers also hosts the popular Dr. Jockers Functional Nutrition podcast.
Thank you so much for being here, Dr. Jockers.
Dr. David Jockers:
Absolutely, Dr. Eric. Great to connect with you here.
Dr. Eric:
For those who have not checked out his website, it is amazing. I don’t know how you put so much great content. How many articles do you have? Hundreds? Probably thousands at this point?
Dr. David:
Yeah, probably 1,500, something like that.
Dr. Eric:
If you are looking on almost any topic related to health, you could probably find it on his website. Definitely check out DrJockers.com.
Before we dive into fasting, can you give a brief background? How did you get into what you’re doing now? How did you get into the fasting world?
Dr. David:
Growing up, my mom was studying to become a naturopath. I was an athlete growing up. That is how she influenced me to eat healthy. My older brother had acne; I didn’t want acne. She said, “He’s eating too much sugar. He’s eating too much processed chocolate bars and candy.” I started avoiding that.
I wanted to perform better in baseball. I was a baseball player. My mom said, “You have to eat kale and your protein. You have to get these nutrients into your system.” Whatever would help me perform better, that’s what I was going to eat. I didn’t like kale, but I was swallowing down kale. She helped inspire me from that perspective.
When I got out of high school, I got really into fitness. I was a personal trainer. I would eat 6-7-8 meals a day. I was always thinner, so I wanted to bulk up. I was eating healthier than most people out there that I knew, but I was eating lots of processed foods. Lots of processed protein bars and protein shakes.
I was eating from the time I woke up until the time I went to bed, and I ended up developing irritable bowel. I overwhelmed my digestive system. I would have cramping and bloating. I went through a period of time where I lost about 35 pounds because I couldn’t absorb nutrients. I was still eating a lot and trying to exercise. Of course, I’m 21 years old, so I think, Well, I just gotta work out more and eat more. I finally hit the fan and realized, Wow, I really need to make changes.
I started reading some different books. I actually had a local guy at my gym who was a chiropractor. He said, “You should really think about becoming a chiropractor.” He was into nutrition. He said, “You should really consider coming off of grains.” This was back in 2003. Nobody was talking about that. But he turned me onto DrMercola.com.
I started reading that website. He talked about a no-grain diet, so I came off grains. I made a lot of changes in my diet. I was more of a plant-based eater, so I started eating grass-fed meats and prioritizing healthy animal products and healthy fats. It definitely changed my health big-time. I got my energy and life back.
I went to chiropractic school. I had this vision of creating a natural health center, impacting community wellness. That’s what I did. When I graduated from chiropractic college, I opened a clinic right out of school. That clinic became successful.
I realized I was working way too much, had no balance. I was living in my clinic for the first two years while I opened it up. I couldn’t get a business loan; it was right after the economy had crashed in 2008. I was working 80 hours a week, stressed out, and eventually bought a house close to my clinic. I started creating a lot more mental, emotional balance.
I also developed skin cancer, which was the kind of cancer that killed my grandfather. He died from metastatic melanoma. I grew up in Florida on the beach. Been sunburned more than somebody should be. I had those risk factors. I was sleeping under the power panel in my storage area of my clinic. I was showering across the street at a 24-hour gym without water filtration. I had an X-ray processor in my main bathroom that I was using, which was a chemical-based processor. I was breathing in toxic chemicals all the time. I overloaded my toxic bucket. For me, that’s how I expressed: it’s been digestive issues or skin cancer. I’ve also been able to heal those.
I actually started practicing intermittent fasting and extended fasting in my journey of healing. When I first started practicing it, I’d never heard the term. Back when I made my diet changes in my early 20s, I realized, because my blood sugar was a lot more stable, I wasn’t hungry in the morning. I was always busy. I had clients early or school early. I started drinking a lot of water early in the day. Then I would not be hungry.
I wouldn’t get hungry until sometimes 2pm or 3pm, and then I would start eating. I would eat in a condensed window from 3pm-8pm. I would eat a good amount of food during that period of time. Then I would wake up the next day and fast or just hydrate throughout the day up until the afternoon again. I realized I felt significantly better. That was a cornerstone part of my healing process. That was back in 2003/2004. I’d never heard the term “intermittent fasting.”
When I developed skin cancer, I went on what I knew was more of an intensive fast. I went on a five-day fast as part of my healing. That was much more intentional. That was right around the time when I started hearing the term “intermittent fasting.” It’s something I’ve looked at and studied in detail, and I’ve practiced myself, too.
Dr. Eric:
That’s some story. It sounds like you have been fasting for about 20 years now. You mentioned you learned about going grain-free when you discovered Dr. Mercola’s website. Just out of curiosity, are you still grain-free? Is it every now and then you have grains?
Dr. David:
I am not 100% grain-free now. I spent years being grain-free. I don’t eat many grains obviously. With the kids, we’ll have some Ezekiel bread from time to time. Fortunately, all of us are very healthy. In general, we are gluten-free. In general, my kids will be like, “Oh, we’re having gluten?” I tell them, “This is the better gluten.” Occasionally, we will have some Ezekiel bread or something along those lines.
It’s rare. I am on a lower carbohydrate diet. I get most of my carbs from fruit, which I eat a lot of. Sometimes some root vegetables. Basically, a very clean template as a whole.
Dr. Eric:
Can you talk about some of the definitions? What is the difference between fasting in general compared to intermittent fasting, for those who are unfamiliar?
Dr. David:
It’s kind of like this blanket term of fasting, intermittent fasting. All of us do some level of fasting. Fasting is just going without. You can fast from entertainment. There are a lot of things you can fast from, not just food. For the purposes of this conversation and natural health, we talk about fasting from food.
Basically, the way that I look at it is it’s within a 24-hour period of time. We call it “time-restricted feeding,” or TRF. Sometimes, the term “intermittent fasting” will come in as well, as synonymous with TRF.
After two days, there is another thing that takes place inside of our bodies. If we’re fasting inside of a 48-hour window, we’re still producing stomach acid, bile, pancreatic enzymes to prepare for the next meal. After about 48 hours, we stop producing those.
If you’re doing a three- or four- or five-day fast, it’s wise to reignite the digestive juices, so you can digest your meal effectively when you do break your fast. Your body is conserving energy. It’s saying: I don’t need to eat right now. I’m not eating, so I need to put all the energy I would normally put into producing these digestive juices, which is very energy-demanding. It takes a lot of energy for us to produce stomach acid, bile, pancreatic enzymes. Instead of that, we’re diverting that energy into healing and repairing.
As we start to introduce food, we want things that will help to reignite digestive juices. A lot of times, I’ll tell people to make your food very aromatic. You’re smelling it. Use a lot of herbs: basil, oregano, thyme, rosemary. Bone broth, something liquid-based that you don’t need much digestive juices for, but tells the body, “Food is starting to come in. Calories are starting to come in.”
With a shorter fast, within 48 hours- For example, I do a 24-hour fast every week. I don’t do any of that stuff. It’s a good idea to take a little apple cider vinegar or drink some broth before a meal. That’s always a good idea.
However, I can do a lunch-to-lunch fast, eat lunch on Wednesday and fast until lunch on Thursday, and not need to worry about if you are going to be able to produce enough stomach acid or digestive enzymes. I can eat a normal meal and feel great afterwards, as opposed to if I do a three-day fast, you can overwhelm your system. You want to have that knowledge beforehand, so you start to gradually reignite and reawaken your digestive system, not break it with this huge meal.
Dr. Eric:
When you say a three- or four-day fast, you’re talking about a water fast. All they are doing during those days is drinking water?
Dr. David:
Typically, water. Maybe herbal tea. Maybe black coffee. Basically, no calories.
Dr. Eric:
Okay.
Dr. David:
I always recommend no sweeteners, or at least minimal sweeteners. The benefit there is you get a dopamine reset as well. For many of us, even in natural health, we are using stevia or monk fruit, and we are having a dessert or sweetening up liquids or eating fruit. All of that triggers dopamine. If we go several days without any sweet flavors, that helps us reset the dopamine pathways in our brain. We are more sensitive to the natural flavors of food when we reintroduce food.
Dr. Eric:
That sounds good. Make sure you could have herbal tea or green tea, but you don’t want to add even stevia or monk fruit, let alone something like honey or maple syrup.
Dr. David:
Ideally, for the best benefit.
Dr. Eric:
You said you do a 24-hour fast once a week. Pretty much on a daily basis, are you doing 16 hours of intermittent fasting?
Dr. David:
Yeah. On a daily basis, 16-18 hours. Sometimes a little bit longer. I’m usually eating my meals between 1-7pm on a daily basis. I typically work out before I break my fast. Usually, I’m working out at 12:30/1pm, and I might finish that workout at 1:30pm and break my fast around 1:45-2pm, somewhere in that range. I have a really good meal. Sometimes, I will have a high protein snack in between. Then I will have a great dinner with my family at roughly 6pm.
Dr. Eric:
I think it’s safe to say that when many people start intermittent fasting, a lot of people are doing it to lose weight. That’s certainly one benefit. Are there other benefits of intermittent fasting?
Dr. David:
I would say that’s the most common benefit. There are incredible longevity benefits to it. I have personally never tried to lose weight at any point in my life, yet fasting has become a cornerstone part of my lifestyle.
When I had IBS, fasting helped me heal my gut lining. When you think about it, the gut lining is only one cell wall. All the mechanical stress of food coming through there, putting stress on that one cell wall. That cell wall needs to be very strong, very resilient.
When we are constantly eating and putting that mechanical stress, I compare that to if you have a sprained ankle. If you continue to walk and run on it, obviously, it’s not going to heal properly. You need time to rest. Fortunately, the gut lining heals a lot quicker than all the cartilage and avascular tissue in our ankle or joints. We don’t need quite as much time to heal our gut lining as we do to heal the joints.
Sometimes, just taking 24 hours, we get a rise in intestinal stem cell production. Even a 16-hour or 18-hour fast, a lot of people will notice big improvements in their overall digestion on a daily basis. One of the reasons for that is the healing. Actual time away from mechanical stress going through there, allowing that intestinal lining to heal.
Another great benefit is it actually helps to improve the diversity of the microbiome. Most microbiome researchers out there will say the more diverse your microbiome, the healthier you are. That’s what the research has shown. The greater number of species of bacteria in our intestinal system, the healthier we are.
How do I create diversity in my microbiome? One way is to eat a diverse array of different vegetables. These plant-based foods have various fibers in them. Each type of fiber or prebiotic nutrient that is in these different plants helps to feed and favor the growth of certain types of beneficial bacteria in our gut. If you are only eating the same 10 foods, you are not going to have as diverse a gut microbiome as if you were to eat 30 different types of foods. That sort of thinking really predominates in microbiome research. There is a lot of truth to that.
However, fasting is the opposite. It’s been shown to improve diversity. You’re not eating anything when you’re fasting. You would think everything is going to die. What we have found is in the gut, there are different layers of bacteria. You have your primary feeders and secondary feeders.
Primary feeders live right above the mucosa. Right above the intestinal lining, you have this thick coat of mucus. That mucus is where the immune component of the intestines are, the secretory IgA. That mucosa protects that single cell gut lining wall. Super critical that we have healthy mucosa there.
Inside the mucosa, there is bacteria that live in there. We call those the secondary feeders. Those bacteria not only like to eat polyphenols and fibers, but they also can survive on the mucosa itself. They can actually eat the mucus itself as a fuel source to stay alive.
One of those secondary feeders is called Akkermansia muciniphila, which means “mucus-loving.” This bacteria has been highlighted by microbiome researchers as what they call a “keystone bacteria,” meaning the levels of Akkermansia muciniphila in your gut are going to be related to your risk of developing chronic inflammatory conditions. If Akkermansia goes down, your risk of developing chronic inflammatory conditions goes up. If Akkermansia goes up, your risk goes down.
How do we favor the development of Akkermansia in our gut? Turns out that intermittent fasting is one of the best ways. When we are constantly eating, we are overfeeding the primary feeders that sit on top. They are eating a lot, and they are growing, and populations are thriving. When their populations are thriving, they are not allowing nutrients to get down deep into the mucosa. They are not allowing for the proper ecosystem for Akkermansia to be able to populate and thrive.
When we actually take longer periods of time between meals, now the primary feeders die down. They are still there but not at higher than normal proportions. Now, when we do consume food, that food is going to get into the mucosa, where Akkermansia can now feed. It will eat the polyphenols and have healthy, balanced levels.
To make more sense, in my front yard, I have an apple tree and a blueberry bush. The apple tree grows, and it grows quickly. It grows to the point where it blocks sunlight from getting to the blueberry bush. Every year, we have to pay somebody to come out and trim the hedges on the apple tree, so we get blueberries. Otherwise, we don’t get any blueberries. We love the apple tree. We love the apples. They are beneficial for us. But if we don’t trim the tree back, then it blocks the key nutrients in the proper ecosystem for the blueberry bush to develop properly.
That is the same thing that intermittent fasting is doing in our gut. It’s creating the right ecosystem for the proper diversity of the microbiome. The more diverse and beneficial our microbiome is, the better our immune system is going to function, the better we are going to break down and absorb nutrients from the food we are consuming, the better we are going to release and get rid of toxins.
We say that good bacteria help to eat toxins and produce B vitamins and all different types of key post-biotic nutrients thar reduce inflammation in our system. The bad microbes will actually eat nutrients, and then they will poop out toxins that inflame us and cause unwanted problems. The more we can create that healthy, balanced, diverse microbiome, the better. Intermittent fasting is one of the core strategies to help optimize the diversity of the microbiome.
Dr. Eric:
I don’t know if you do stool testing at all in your practice. If someone does a comprehensive stool test or even a gut microbiome test, and they have a lot of low bacteria, and perhaps even low Akkermansia, because now some stool panels will test for that, is it a fair strategy to incorporate intermittent fasting based on what you said to try to increase those numbers? Maybe that’s not the only strategy. Maybe you do want to make sure you are getting enough fiber and prebiotics. Quite frankly, I never thought about incorporating intermittent fasting to improve the gut microbiome.
Dr. David:
I understand. Some level of intermittent fasting should be in everybody’s plan. I call it a fasting lifestyle. It’s part of a healthy lifestyle, like exercise. For example, I just had a flu last week. I work out six days a week. I’m in great shape. When I had the flu, I couldn’t work out. I needed rest.
There are seasons where you may not fast quite as much as other seasons, depending on what your overall stress load is. Some level of TRF/intermittent fasting should be a cornerstone player in every single person’s healthy lifestyle approach. Same thing as exercise. Should be a part of what you’re doing on a regular basis.
Yeah, you are going to want to make sure you are getting the right amount of fiber for your body type. I don’t know if this has been your experience, Dr. Eric, but in my experience, some people really thrive on very high fiber, high phytonutrient diets. Other people, lower levels of fiber and FODMAPs and plant fibers in their diet. You have to find where you’re at on that spectrum.
You’re looking for your fiber threshold, in a sense, trying to get it from real, whole foods and find where the level of fiber hat you really thrive on is. That may be a lot different than your spouse. They may thrive on 20g of fiber more than you. You get your gut inflamed and bloated when you are consuming that much fiber.
Eating the right types of foods obviously, and then also incorporating intermittent fasting, stress reduction, good sleep. All the things we talk about should be at the foundation of your lifestyle.
Dr. Eric:
I agree with you that everybody is different when it comes to fiber consumption, the amount that they need.
Who isn’t a candidate for intermittent fasting? Is there anybody who should not fast?
Dr. David:
When it comes to an overnight fast, pretty much everybody can do that. Roughly 10-12 hours, overnight fast, at the baseline is really for everybody.
A pregnant woman may need to consume something overnight. My wife was able to fast 10-12 hours overnight without any issues with all of our kids, and they were all super healthy. As we start to push that fast to 14-16-18 hours, pregnancy is not the time. Pregnancy, you’re growing and developing.
My kids have no issue. They typically fast 14 hours overnight. They have no issue as long as they’re consuming plenty of calories during their eating window. For most kids, it’s not like we’re trying to compress their eating window or do something intentional there.
High-level athletes, if you are training 2-4 hours a day, it’s not a season to be trying to tighten your eating window.
Type 1 diabetics, until they get really good at understanding where their blood sugar is, because there are type 1 diabetics who do regular intermittent fasting and feel great. It’s not something they’d want to jump right into. They need to be really good at understanding where their blood sugar is and how their body is responding to various foods they are consuming.
People who are very underweight. They need to understand the amount of calories that they are going to need and the amount of foods they are going to need. That’s one of the biggest mistakes they make. They feel good when they’re fasting, so when they get back to eating, they don’t eat enough. They are used to eating smaller meals maybe. They are not consuming enough overall calories, enough overall protein.
That’s one of the key caveats. When you’re eating, you eat really well. You want to make sure you are eating until you are fully satiated and not try to undereat. A lot of people are in this diet culture where they say they are going to eat only 200 calories a meal. They go from six meals to three meals. Then they are just consuming 200-250 calories in a meal. They are not getting the overall amount of calories that they need.
When you are in a period like that, where you have too low calories for too long a period of time, that will affect your metabolic rate. Talk about thyroid. It can affect thyroid hormone production and conversion. Sex hormone production as well. Cause a lot of unwanted symptoms.
You have to make sure that when you eat, you’re eating really well. Eat good foods, and eat plenty of them. When you’re not eating, you’re not eating.
Dr. Eric:
Getting enough protein is important I would imagine as well.
Dr. David:
I recommend 30-50g of protein per meal. Now you’re only eating 2-3 meals per day, but you’re consuming 30-50g of protein per meal. 30 at the minimum. Roughly about 10% of most proteins is branched-chain amino acids: leucine, isoleucine, and valine. Those branched-chain amino acids stimulate muscle protein synthesis, the development of muscle tissue. Roughly about 3g or so, depending on your size, of leucine per meal is what we call the leucine threshold, which stimulates muscle protein synthesis. Leucine is the most abundant branched-chain amino acid and the most important for muscle protein synthesis.
A smaller individual may be fine with 20-25g of protein in a meal. If you’re under 110 pounds or so. For most adults, just to be on the safe side, I recommend 30-50g of protein per meal. Protein is very satiating. That is going to make you feel much more satiated and keep your blood sugar stable and balanced, so you can go longer periods of time and feel great between meals.
To get 30-50g, you may need to readjust. You may have been used to consuming 10g of protein. You need to understand what that really looks like as you’re setting up your meals. If you do 30-50g of protein in a meal, you will feel great. Fasting is going to be a lot easier.
I obviously recommend adding in some fats. If you are eating real foods, most protein foods come with some fats. Let’s say a chicken breast doesn’t. Add some olive oil or some avocado, so you are getting some healthy fats with it.
I recommend 15-30g of healthy fats. These are general ranges. Some people can do larger amounts, like I can do much larger amounts of fats and proteins in a meal, and I feel great. When other people eat a lot of fat in a meal, they feel awful. If you don’t have a gallbladder, or if you have really clogged bile ducts in your biliary ducts in your liver gallbladder system, and are not releasing bile effectively, you may feel bad. You may feel more nauseous, have more gut issues, feel really itchy when you consume higher amounts of fat.
This is where a lot of people go wrong when they go on a ketogenic diet. They are told to keep layering on the fat. Add more butter to that. Eat a whole avocado with that meal. For some individuals, they feel great when they do that, and others don’t. They are not metabolizing that fat effectively.
Find out what you feel best with as far as the amount of fat you are going to consume in that meal. Stick in that range. For most people, it will be somewhere between 15-30g of healthy fats, coming from extra virgin olive oil, avocado, grass-fed meats, pasture-raised eggs, grass-fed butter, something along those lines. Combine that with the protein.
Then you can round out your meal with vegetables. I like to get a lot of colorful foods in my meal with fruits and vegetables.
If you get your proteins and fats down right, that will give you the natural satiety that you need, which will keep your blood sugar stable and make it a lot easier to fast and keep you at a very high energy throughout the day, functioning at a really high level, and keeping your inflammation down.
Dr. Eric:
Pretty much it sounds like you’re recommending for people to listen to their bodies, especially with fat consumption. Maybe they need some additional support if they had their gallbladder removed for example. That goes beyond this conversation. Appreciate you sharing that.
When someone is, let’s say extremely restricting calories, you mentioned how it might negatively affect thyroid and/or the sex hormones. As you know, most people listening to this have a thyroid or autoimmune thyroid condition. If someone is doing everything right, not restricting calories, making sure they are eating sufficient protein and healthy fats, are there any concerns with someone who has a thyroid condition?
Dr. David:
There are none. In fact, fasting is one of the best things to help reduce overall inflammation, to help the body get rid of senescent immune cells. Whenever I think about autoimmunity, where the immune cells are starting to attack our own tissues, those immune cells are really dysfunctional, so our body has to constantly recycle cells. It will recycle immune cells constantly.
However, if we are not good at recycling and getting rid of older, damaged, dysfunctional cells, that is a skill that the body has. As people age, if they don’t create the right environment, they are not going to be able to get rid of these cells. Therefore, those cells will start to produce, and the things they are doing are not in alignment with our best health.
One of the best ways to get rid of senescent cells—that is the term we use for old, aged, dysfunctional cells—is through fasting. When we fast, we lower our blood sugar and insulin levels. Once insulin gets below a certain threshold, it tells the body to go into healing and repairing.
When insulin is elevated, it’s saying, “Let’s build and divide. Let’s create more cells. Let’s store.” When insulin goes down below a certain imaginary threshold that could be different for each individual, all of a sudden, the innate intelligence that runs our body says, “Now is the time to heal and repair. Let’s get rid of all the different damaged proteins that we don’t need. Let’s break those down. Let’s take the raw materials and create new, healthy cellular organelles; new, healthy mitochondria; new, healthy Golgi apparatus; new, healthy RNA. Let’s get rid of these old, damaged cells.”
Now, we start to repair and refresh the body. The problem is that most people are in a constant state where insulin is above the threshold, so they are in this constant state of building and reproducing cells, and they are not getting enough time to clean and repair. Because of that, we build up all this trash in our system, all these damaged cells, and those damaged cells can release all different types of inflammatory compounds, histamines, antibodies for certain individuals. Based on our genetics, we will have our own unique expression. That is where the problem is.
Outside of that, fasting needs to be a key component for anybody who is trying to heal from chronic inflammatory or autoimmune conditions because it moves that switch. It moves us back into healing and repairing, and that creates the environment we need to heal and repair properly.
Dr. Eric:
A lot of people listening to this have Hashimoto’s. On top of the autoimmune component, they are trying to lose weight, so fasting can have multiple benefits.
Maybe a little bit of a different story for some people with Graves’. You mentioned weight loss. If someone has hyperthyroidism and is losing a lot of weight, maybe they want to do things to improve their health first before incorporating fasting.
You’d be amazed as to how many people with hyperthyroidism, including Graves’, actually gain weight. I know on the surface this doesn’t make sense. If someone has that increased metabolism, you’d think just about everybody loses weight with Graves’, but that’s not the case. If someone is gaining weight, from the standpoint of the autoimmune component, whether it’s Graves’, as long as they are not losing a lot of weight, or Hashimoto’s, or RA, it sounds like if anything, it would be beneficial for that autoimmune process.
Dr. David:
Absolutely. Even somebody who is losing weight, actually taking that period of time between meals. When I had IBS, I started doing this, and I was way underweight. It helped me gain weight. When insulin goes down, not only do we heal and repair, but we absorb nutrients more effectively when we do consume food. When someone is very underweight and is eating a lot, it’s because they are not absorbing nutrients. They are creating this vicious cycle of inflammation. That inflammation is not allowing them to get what they need from the food they are consuming, so they need a reset. That’s what fasting offers.
Also, when we fast and insulin goes down below that threshold, another hormone called human growth hormone (HGH) becomes elevated in our system. HGH and insulin are antagonistic. One of HGH’s main functions is to protect lean body tissue. HGH helps increase circulating leucine levels, which is that branched-chain amino acid that tells the body to hold onto muscle tissue, bone tissue.
I was very catabolic. I was eating plenty of food, but I couldn’t gain weight. My body was breaking down its own muscle tissue, bone tissue, joint tissue because my environment was wrong. When we create the right environment, now the HGH is elevated, saying, “Protect muscle tissue. Protect bone tissue. That is precious tissue. We are going to leave that alone. Instead, we will break down fat for fuel while this individual is fasting.” That is the environment we want, so we need that reset.
We also need to make sure, when we are eating within our eating window, that we are consuming plenty of quality calories, blood sugar stabilizing calories, and providing the nutrients that we need to build new tissue. Good, high protein. That is key.
Even if somebody is underweight, even if we are just starting with a 12-hour overnight fast or a 14-hour fast, and trying to consume 3-4 meals in that window, and trying to make those meals as easy to absorb as possible. Maybe protein shakes, broth, things like that, in the early stages, while those individuals have broken ankles. It’s really hard for them to walk, to consume and absorb nutrients from a lot of solid food. We might even need more liquid nutrition for those individuals as we are healing and repairing that gut lining, so they can absorb the proper amount of nutrients from real food.
Dr. Eric:
I’m glad you brought that up as far as the duration of the fast, too. Just about everybody should be going at least 12 hours. Even 14 hours is not too long when you think about it. If someone stops eating dinner at 6pm, and they eat breakfast at 8am, which is fairly early, that’s 14 hours right there. Maybe if someone is losing a lot of weight, maybe they don’t want to start out with a 16-hour or 18-hour fast. But 12-14 hours isn’t too bad.
Dr. David:
Whenever somebody is losing a lot of weight, you have to look at their diet. They may be eating a lot, but they may be eating a lot of saltine crackers, a lot of foods telling their body to be more catabolic. Are they eating steaks? Are they eating grass-fed beef? Are they getting their protein amount right? That is one of the big things I want to look at. Are you getting enough protein? Are you getting enough healthy fats?
When you start to make those diet changes and incorporate fasting, we get their environment switched back to this place of healing and repair, and they are able to absorb nutrients.
Dr. Eric:
I want to switch gears and talk about foods that can break a fast. I had questions about green tea and herbal teas. MCT oil. Even coffee. Without any sweeteners, even the natural sweeteners, if you just have black coffee, regular black tea, green tea, herbal teas, are all those safe to drink?
Dr. David:
Good question. Somewhat personalized. The general statement would be that none of those break a fast. The caveat here is if you consume something, even black coffee, and it increases cravings.
Black coffee is a performance enhancement tool, meaning you should feel great after you drink coffee. Some individuals feel more anxious, jittery, or have increased cravings. When they consume it, their body is having an adverse immune reaction to it. For that individual, that will break their fast. It’s a stressful event. But for most people, that’s not the case.
When we start to add in sweeteners, that is when more cravings start to develop. If you are noticing an increase in cravings as you’re fasting, that’s a sign your body is having trouble with blood sugar and burning fat for fuel. It’s having a metabolic flexibility event.
Normally, we are burning glucose in our bloodstream. We eat a meal and have extra glucose. We have glucose tied up in our muscles and liver. Our body starts to metabolize that and break it down. After a certain period of time, insulin comes down, and we start to burn fat for fuel.
Now, our brain continues to run off sugar, but a lot of our muscle cells and other cells are running off of fat and glucose. Then we get to a point where we don’t have a whole lot of glucose available, even to provide the needs for our brain. Then our body will take stored body fat or fat from our diet and create ketones.
It brings the fatty acids to the liver and creates a smaller molecule. Fatty acids can’t cross the blood-brain barrier; they’re too large. Ketones are a smaller molecule, a breakdown product of fatty acid metabolism. Those are able to get into the brain and be used as an energy source for the neurons.
Also, ketones are what we call an epigenetic modulator. In a sense, they send signals to different functions in the body. One of the signals that they’ll send turns off what we call the neuroinflammasome, or the inflammasome in general throughout our body is this inflammation amplifying system. It amplifies the message of inflammation throughout the whole body. Ketones can turn that off.
They also help to regulate the glutamate to GABA balance in our brain. Glutamate is the excitatory neurotransmitter. It’s like hitting the gas pedal, so it helps us think sharply and quickly, have great memory. GABA is the brakes, which help us be more calm, relaxed.
When we have too much glutamate, which is common when we have neuroinflammation, then we end up with anxious thoughts. We end up with a lot of nerve cell death, which can cause things like depression. The ratio of glutamate to GABA and how ketones will help balance that will help keep us where we’re functioning, where we’re still thinking sharply and quickly, but we are also able to calm our thoughts and be in a very calm physiological state.
This is where we normally should be. When we’re fasting, we should have lower levels of inflammation throughout our body and our brain. The ketones shut down the inflammasome. Then this optimal glutamate to GABA balance. We should be able to thrive and feel great and be able to perform at a very high level.
In fact, a lot of people who have done extended fasts have talked about greater intuition, greater foresight, spiritual breakthroughs, emotional breakthroughs. Linking that back to what’s happening physiologically that can contribute to that, it will be the lower levels of inflammation, the better metabolic flexibility in the neurons, the optimal glutamate to GABA ratios. They will allow that individual to have an enlightened state.
Some great benefits there. We can get a lot of those benefits while we are intermittent fasting. For example, I haven’t eaten anything since 6pm last night. I feel great, as I’m doing this interview. I feel really mentally clear, mentally sharp, not hungry. That is because ketones are elevated in my bloodstream, so my neurons are able to run off of those. They are also utilizing glucose for energy to help me think sharply and quickly. I have that metabolic flexibility, where I am burning fatty acids, ketones, and glucose as energy sources. That is a sweet spot, where we are good at burning all three fuel sources.
Dr. Eric:
It’s close to noon our time, so it’s been close to 18 hours. You said 6pm last night. You said you’re still feeling good, not dying to have something to eat. Even though a 16-hour fast is sufficient to help with that glutamine to GABA ratio?
Dr. David:
Yeah, it is. The key there is it will be different for each individual. It depends on your insulin sensitivity. The better your baseline level of insulin sensitivity, the less you need to fast to get those benefits.
For example, if I eat a meal, and let’s say this meal is not very blood sugar stabilizing, it will throw off my blood sugar. Let’s say my insulin goes way up, and it takes 12-14 hours to come down. Then I will get less of the ketone production before I break my fast. That’s 16 hours. Does that make sense?
As opposed to if I eat a much more blood sugar stabilizing meal. My insulin comes down 6-7 hours after that meal. Now, my body is already burning fat. It’s already producing ketones. Now, I have a lot more time to get the ketones elevated in my bloodstream before I break that fast again.
Dr. Eric:
That makes sense. I know we have to wrap things up, but I want to make sure: Is there anything else you’d like to discuss? Anything I should have asked you that I didn’t ask you?
Dr. David:
No, this has been a great interview. We talked a little bit about autophagy, this process where the body will break down old, damaged cellular organelles and take the raw materials and form healthy cellular organelles.
The most well-known are called mitochondria, in a process called mitophagy, where we are breaking down the old, damaged mitochondria and forming new, healthy mitochondria. This is critical for the overall functional wellbeing of every cell in our body. Ultimately, at the end of the day, our quality of life is going to come down to the amount of high functioning, stress-resilient mitochondria within the cells of our body.
For most individuals out there, because they are not cycling through feeding and fasting, they are not providing the environment for healthy mitochondria. Instead, they’re providing an environment where they have a whole bunch of senescent, old, damaged, dysfunctional mitochondria within the cells of our body. Their overall cellular genetics goes down. Their overall inflammatory load goes up. Their overall oxidative stress load goes up. Their resilience in life goes down. We want to have great resilience. We want to have our mitochondria primed for stress as well as possible. Primed means they are ready, prepared for any sort of stressor because stress comes in life.
By making sure our body has time throughout the week to get rid of all of the older, damaged mitochondria, mitochondria are constantly being damaged and rusted just from metabolism, from producing energy, from all the different stresses that we experience. We just have to get rid of those and build new, healthy, stress-resilient mitochondria. The more of those stress-resilient mitochondria, the better we will adapt to the stressors we face throughout our life, and the better we will be able to function and perform. That will also create a healthy body that is primed for longevity as well, so we are ready to live 80-90-100 years disease-free.
Dr. Eric:
When we think about mitochondria, obviously what you eat is important. Basic eating well, stress management, getting sufficient sleep. The fasting component of it is fascinating.
We covered a lot, Dr. David. You shared a lot of great information. But the good news is he has an upcoming Fasting and Longevity Summit. If you could take a minute or so to talk about that?
Dr. David:
The Fasting and Longevity Summit, myself and Dr. Joseph Antoun, who is a Ph. D and researcher, we interviewed a wide range of different natural health experts and got their best strategies for having success with intermittent or partial or extended fasting as well as everything to do with longevity: hyperbaric oxygen, good nutrition, stem cells, all these biohacking strategies that people can be doing to help support their overall health as they age.
Not only are you going to learn about how to prevent or reverse chronic disease, but how to stay disease-free and age with those great stress-resilient mitochondria, like I was talking about, so you can thrive into your 80s and 90s.
Dr. Eric:
That’s awesome. There will be a lot of talk about fasting, but it sounds like it goes well beyond that, so other components help with longevity, too.
Besides the summit, check out Dr. Jockers’ website, DrJockers.com. Your podcast as well, The Dr. Jockers Functional Nutrition Podcast. I don’t know if you want to direct them toward social media at all.
Dr. David:
I’m on YouTube and Instagram as well. If they want to look me up, Dr. David Jockers.
Dr. Eric:
Dr. David, I appreciate your time. I’m sure the listeners learned a lot about fasting. I learned some things as well.
Dr. David:
Wonderful. I enjoyed my time with you here, Dr. Eric. Appreciate all the great work you’re doing.