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Intermittent Fasting With Dr. Amy Shah: The Key To Metabolic Flexibility


In today’s episode, Dr. Amy Shah joins Dr. Lattanza to discuss how intermittent fasting can be a life changing tool when it comes to resetting your metabolism. She explains why people may struggle with incorporating this routine into their life and shares the best ways to set yourself up for success. Listen in and find out how to lose weight, reduce your risk of certain diseases, and improve your sleep by mastering Circadian Fasting. Through this you will have the power to become metabolically flexible and utilize energy more efficiently.

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Intermittent Fasting With Dr. Amy Shah: The Key To Metabolic Flexibility

I am so excited to bring you the guest for this episode as we’re going to be talking about intermittent fasting, gut health and improving your energy. We have Amy Shah, MD. She is a double board-certified Medical Doctor and Wellness Expert specializing in food allergies, hormones and gut health. With Cornell, Harvard and Columbia training, she helps busy people transform their health using cutting-edge, nutritional and medical science.

She has proven techniques to heal inflammation utilize the power of the microbiome to help digestion, obtain natural hormone balance and heal food sensitivities. In addition to Dr. Shah’s clinical work, she has written the book called I Am So Effing Tired, which resonates deeply within all of us. She has created, where she is especially well known as an expert on intermittent fasting for women. Welcome to the show, Dr. Shah. How are you?

Thank you so much for having me. I’m so glad to hear that we’re physical neighbors. During this pandemic, I’ve been doing shows and talks with people from all over the world, so it’s cool to see that you’re just right next door.

I know. We’re stone’s throw away and we wouldn’t have even known. I googled you and googled your office and came to find out that we are absolute literal neighbors, which is excellent. I’m super excited to dive in. I had shared that I was going to be speaking with you and a lot of my Instagram followers were like, “The book title alone.” Have we not all said it time and time again? I love that it is a major focus of your work because it shouldn’t be the new normal. It shouldn’t be accepted that we’re exhausted all the time.

If you’re doing what is normal in society, you are on the fast track to fatigue and burnout. For me, that was a big wake-up call when I thought I was doing what everybody else was doing, but I felt exhausted. I felt that I wasn’t doing my best work. I was feeling anxious and I couldn’t sleep. I knew there was something wrong, but when I went to get my physical, everything turned out “normal.” That’s basically what started me on my journey.

The funny thing is the biggest criticism I get of the book is that there’s no magic. “She doesn’t give any magic prescription.” That was a big negative review and it makes me laugh because wouldn’t it be nice if there was a magic pill that we could all take and not do the hard work? Time and time again, it’s the hard work that makes you through and changes things.

There is no easy button and we would all push it if there were. Unfortunately, we go through life with the best of intentions, doing our work, raising our kids, all of the things that we have to do and our plate is loaded up. We can’t be like, “Here’s the magic energy fix,” but we got to do the work.

We want coffee to be that desperately, but it’s not.

HHS 17 | Intermittent Fasting
I’m So Effing Tired: A Proven Plan to Beat Burnout, Boost Your Energy, + Reclaim Your Life

We sure do. I know that intermittent fasting is a big topic that everybody has. If they haven’t tried it themselves, they at least know what it is, but you have an interesting take on this. Let’s talk a little bit about circadian rhythm and how your take on intermittent fasting plays into that.

Many of us have heard about intermittent fasting now because it’s the most googled diet of 2019. It continues to be extremely popular. However, nobody knows what that even means. What does it mean to intermittent fast? Are you supposed to fast for 12 hours or are you supposed to fast for 24 hours or do you need to fast for 3 to 5 days to get the benefits? I was in the same boat because there’s not a lot of medical literature that tells us how to fast. I played around with all these different types of fasting.

What I found from my personal experience and from what I was reading that matched that was that the easiest form of fasting that gave me the best results was something called circadian fasting. The reason why I think that was the case is, one, I’m busy. I’m time-strapped. It’s difficult for me to do long fast without taking off from work or from being a mom. I chose overnight fasting, which sounds like, “Aren’t we all supposed to be overnight fasting?” No. Most Americans are eating 16 hours a day, leaving only eight hours of fasting time.

Even if you were going to stretch that out to 12 hours, that’s when circadian fasting starts. Circadian fasting is fasting overnight for 12 hours or more. A simple concept, but evolutionarily, that is how we’re programmed to eat. If you think about a hundred years ago, there were no drive-throughs, microwaves, Uber eats. We had to stop eating at some point in the day or at least would have smaller meals later in the evening. We wouldn’t be having our biggest meal of the day at midnight or 11:00 or 10:00 even. It would be closer to sundown most of the year.

That’s circadian fasting would seem to me evolutionarily sound. Even though we’re changing a lot, our genes don’t change over 100 years. A few changes happened, but we are programmed to be digesting mainly during the middle part of the day. That’s this concept of circadian fasting. Circadian rhythms are the 24 hour day and night cycles that our bodies run on. If you are any type of living being, a bacteria, a plant or a human, you have an innate circadian rhythm that your body works on. Eighty percent of our body’s functions work on this day and night pattern, meaning that our body knows that it should turn on certain brain and body functions during the day. During the night, it should turn on separate ones. That way, we can optimize our bodies.

What we’re doing in our life is we’re completely messing that up. We’re disregarding it altogether, not getting any nature time during the day, so our body does not know day from night. Sun is the biggest input you can be giving your circadian rhythm. We’re eating at all crazy hours, trying to force our bodies to digest in the middle of the night, which is why we have so many digestive issues. We’re saying, “We’re not going to sleep because you sleep when you’re dead.” We are telling our body mixed signals as if we were traveling across the world every night. We’re in this perpetual jet lag state where we feel exhausted or zombie-like creatures.

We think that things like energy drinks and coffee are going to help us regain that energy and it’s not so. That’s why I feel passionate about the circadian fasting piece because it’s a piece that even I did not understand as a physician. I know it makes sense. Eat healthy, fuel for your body and that’s going to make you more energetic. I got the fact that exercising like, “Yes, that makes me more energetic,” but this whole piece of circadian rhythms, intermittent fasting like timing my day, that was new to me and changed a lot of things. That’s why I talked about it a lot.

You say 80% of our bodily functions are based on the circadian rhythm and we can’t continue to ignore it and expect that all is going to go according to plan.

People who did overnight fast for 13 and a half hours had a 36% reduction in breast cancer recurrence. If there were a medication that could do that, it would be a billion-dollar drug.

It’s so interesting. I always say in presentations that 80% of your body works on circadian rhythms. There are only a few things like heartbeat and breathing that have to go on at all times of the day. This new study that came out, a huge study about how the heartbeat also has a circadian pattern and that your heart knows or that circadian input tells your heart at night that it doesn’t have to have so much reserve in it. That can go into relaxation mode because it anticipates that you’re not going to be running away from something in the middle of the night. It’s more so than we ever knew. That’s how much circadian rhythms affect our bodies.

It’s going to continue to come out more. We’re learning more about light exposure, the blue light versus the orange or yellow light. All of that plays into even hormone function.

The hormonal function is definitely on a circadian pattern.

How would intermittent fasting or circadian rhythm fasting vary for women in particular?

This is the million-dollar question because we know anecdotally. We see articles about it. We see bloggers talking about how intermittent fasting ruin their life. This is how I explain it. It’s akin to exercise. When women athletes over-exercise, we see this all the time, without a recovery period. They don’t get their periods. They skip their hormonal cycle. Their hormones become very imbalanced and they lose fertility. It’s the same thing with fasting. If you put immense stress on our body, as a woman, whether you want to get pregnant or not, your body will protect itself by shutting off your GnRH, which is the leader hormone up in your brain. It will stop that pulse for a little while, while it’s in a stress state.

Evolutionarily, if you’re in a famine, in a war, or in a very stressful situation dealing with the infection, your body shuts off reproduction, which then affects your hormones. You can imagine that’s going to cause a cascade of symptoms. Women, we all know that our hormones rule our mood and our hunger and fertility. Many women have experienced this extreme form of hormone disruption due to fasting. This is because the same thing with women exercisers, gymnasts and Olympic athletes and ultramarathoners deal with this all the time.

What I wanted to write about in my book is that, “You can get the benefits of fasting without going to the extremes. If you want to go to the extremes, there’s no reason that you can’t as long as you have a good recovery period and you work on that recovery.” I make it akin to exercise that overnight fasting, like a circadian style fasting is like going on a daily walk or jog. It’s stressful but not too stressful. Whereas doing a 16-hour to 24-hour fast is more akin to running 10 miles. You can do it, but you would never do it on the first day. You wouldn’t want to do it every day from day one and on, which is how people start intermittent fasting.

The one animal study that was done on female rats that people in the “social media world” is a rat study where they had the female rats fast for 24 hours. Remember that rats’ metabolisms are three times at least ours. Imagine fasting for that period of time and it was supposed to be every other day fast. It was done for 12 weeks, which in humans would mean years of doing a three-day fast. You can imagine that had an impact on the ovaries. That study is hilarious to me because I’m like, “You’re telling women the entire 50% of the world population, maybe more, that you shouldn’t do intermittent fasting because of one rat study. It’s like saying that women should not exercise.” We shouldn’t ever say that because you’re leaving so many benefits on the table by saying, “Because there’s an extreme form, don’t do it at all.” That’s my take.

HHS 17 | Intermittent Fasting
Intermittent Fasting: You can get the benefits of fasting without going to the extremes. If you do, make sure you have a really good recovery period and work on it properly.

There is an error in translation there. Ovulation and pregnancy are physiologically expensive that your body’s going to say, “I can’t afford to do this now.” It’s going to stop that entire process and as you said, everything downstream takes that hit.

Intermittent fasting is like any form of stress for women. We have to be a little more mindful when putting ourselves and our bodies through a stressful experience. It doesn’t mean we shouldn’t. It just means that we are not little men and we have to do that accordingly.

We want to work on our metabolic flexibility getting into it and that’s why you do start slow.

That’s the big thing, the metabolic flexibility part.

How would that be translated into women over 50 or post-menopausal women?

The best thing about post-menopausal women and you hear all this bad news, but the good news is that you’re no longer going to have to deal with that wiring of GnRH shutting off in times of stress. Your body is no longer producing or barely producing those hormones, so you have less of a flux every month. You’re able to do things that you weren’t able to do before, like intermittent fasting for longer periods of time without having the repercussions.

It’s still focusing on metabolic flexibility but maybe a little bit more leeway in that whole process. If patients or people are new to intermittent fasting, what are some ways you suggest to combat cravings and avoid feeling hungry during those fasting hours?

There are a few different options. The best option is to do short fasts in the beginning. As you said, work on your metabolic flexibility. You’re not going to be able to go from high sugar, high carbohydrate diet where you eat every two hours to be being able to fast for sixteen hours. It’s not going to happen overnight. It’s like saying you got up from the couch and you want to go for a half-marathon run. You need to train for it. You train in short intervals, master that, and go to the next level, so 12 hours and 13 hours.

Most people these days don’t get enough nature time, leading to a lack of input for the body’s circadian rhythms.

The best study about this is Ruth Patterson, a cancer researcher, read all the literature about intermittent fasting about how it lowers inflammation and insulin levels which seemed to drive cancer in many ways. She decided that she was going to do a study on intermittent fasting, but she wanted to make it easy because her patients were women who already had breast cancer. They were trying to do things to prevent it. They were usually people who had gone through a lot with chemo, radiation, surgery, etc. She prescribed them a very easy intermittent fasting schedule, overnight fasting, as I talked about with the circadian rhythm of about thirteen hours. The other group was less than thirteen hours.

You could do more than thirteen hours or you could do less. The average fasting interval for the intervention group was 13.5 hours of overnight fasting. She followed them for seven and a half years. She found that the group that did the overnight fast, only 13.5 hours, had a 36% reduction in breast cancer recurrence. If there was a medication that did that, it would be like a billion-dollar drug. This is a very moderate, easy and doable intermittent fasting length. I encourage people who are trying it for the first time not to feel like they need to jump the gun and do a super long fast because that’s what they heard on some weightlifting website to start with something moderate and modest. You will start to see the benefits right away.

You’ve mentioned the comment about your book not having a magic pill. It’s like, “Everybody has the option to be doing this but here, let me give you the guidance and maybe you’ll do it.” You see these staggering results.

The thing is that if we could make intermittent fasting into a pill, it would literally be a blockbuster thing that no one had ever invented before but because it’s something that’s free and accessible, it is hard to market that in this world. As you know, there’s a lot of marketing that goes into medications and therapies.

This is a much lower risk than taking something with other side effects. Most of the known side effects of fasting, especially at this length, are quite beneficial.

It’s because we think about it as exercise. I say it’s akin to exercise. Yes, injuries happen. You have to be careful, start slow, train yourself, move up and stress your body enough so that you can become more metabolically flexible but not that you get hurt. It’s like exercise. You would never say, “There’s a potential to get hurt, so don’t go walking every day.” That’s ridiculous. It’s preposterous. It’s the same thing with intermittent fasting.

In the medical community, a lot of people have said, “There are no double-blind, randomized controlled trials that prove that it is better than placebo. Why would we do this?” I say, “One, it’s free and two, it’s like exercise.” When you try to compare exercise to sitting, it’s hard because somebody might say, “Is Tai-Chi better than sitting?” Somebody might say, “Is running a marathon better than sitting?” The intermittent fasting studies now are all over the place. It’s like comparing all kinds of fasting and what they were finding is they got mixed results. That’s why it’s been more difficult to accept. In any case, low risk, high yield in many ways. It’s something to incorporate, even in the smallest way, into your diet.

On that note, by comparing it to exercise, what is your take on exercise during a fast? I’m talking about a twelve-hour fast.

HHS 17 | Intermittent Fasting
Intermittent Fasting: Post-menopausal women no longer produce GnRH hormones. You have less of a flux every month, allowing you to do intermittent fasting for longer periods without having repercussions.

This whole concept of metabolic flexibility brings up the concept of the metabolic switch. Dr. Mattson, who is a neuroscientist published an article in the New England Journal of Medicine in December 2019 that talked about intermittent fasting as a tool. Not because it lowered calories but because it turned on a metabolic switch and everyone said, “What is he even talking about?”

What he’s talking about is that we love to use glucose as fuel. Our bodies use glucose as their primary source of fuel. If you eat an orange now, your body will use the glucose that gets released into your bloodstream for the next activity that you do because it loves fresh glucose. Once you run out of glucose in your bloodstream, your body has to look for other sources. There’s some stored glucose in our liver, so it will go to the glycogen stores in the liver and it will take some of that.

If it runs out of that, then that’s it. Basically, either you have to eat and replenish your glucose stores again or the body has to make a switch. This metabolic switch naturally happened every night for thousands of years and over the last 50 to 100 years, it never happens because we eat as soon as we go to bed or right before we go to bed and we roll out of bed. People are like getting their coffee and their first bites immediately after they wake up. We never deplete that glucose, the glycogen and we never turn on this metabolic switch. It has so many benefits.

When the metabolic switch gets turned on and turned off, you turn on all these downstream benefits. It’s like when you work out and you do muscle training, you don’t work on your muscle now. It gives you all these brain and body inflammatory benefits later. Similar to that, the metabolic switch has many benefits. The reason why I’m talking about that in the setting of exercise is because if you do an overnight fast and you pair it with a fasted workout in the morning, you have your best chance of turning on that metabolic switch.

Now, not only did you use up the glucose during your sleep, you’re extending the time that your body can start to use up more glucose and glycogen. You’re then putting it through a workout, which obviously demands more glucose and glycogen from your body. It’s making the likelihood of turning out a metabolic switch much higher and almost always likely unless you had a huge carbohydrate-loading meal right before bed. We don’t have a way now to know exactly when that metabolic switch happens, but it’s usually between 12, 14 to 15 hours. If you’re fasting even 12 to 13 hours, but then you’re doing a fasted workout at the end of it, you have a really good chance of at least turning on that metabolic switch.

There’s some fear surrounding that. It’s like, “I have to eat something before this workout. I’m not going to have enough energy to get through my class or my walk or my run,” or whatever that might be. For those who have worked up to at least this twelve-hour fast and go into a workout, you would be pleasantly surprised about how responsive your body is and how resilient you are.

I think, in the beginning, I was only able to do yoga or walk in the morning fasted because people tell me all the time, “How would you work out fasted?” It’s hard in the beginning because it’s this mindset shift, but once you get used to it, you’ll go from taking a walk or doing a small yoga class to be able to do a full workout.

I love how you especially focus on outdoor exercise and getting that sunshine piece into the circadian fasting and doubling down with the meal timing and the sunshine exposure. You’re taking all of that into account.

The brain and gut are connected. If your gut is inflamed, tired, or unhappy, the brain will feel it accordingly.

We have a sun deficiency in our world. We don’t get enough nature time, which has been proven to improve health outcomes. We don’t get enough input for our circadian rhythms. Luckily, Lauren and I live in a place where we could get natural light almost all times of the year and people still don’t take advantage of that. It’s because there’s a lack of education around it, even in the medical field. Hopefully, things will change soon.

People underestimate the power of the sun, even though you and I feel that sometimes we live on the surface of the sun. I’m sure in the clinic, you and I both still see vitamin D deficiency all over the place and poor sleep because we’re not utilizing that. We’re not harnessing the power of nature.

I take my vitamin D, for sure.

We had alluded to the title of your book, I’m So Effing Tired. We then got into talking about circadian rhythm and fasting. How do diet and fasting play into the energy level?

It’s hard because we never learned the connection between food and energy, but here’s the crux of it. Our brain and our gut are connected. Meaning that if your gut is inflamed, tired and unhappy, your brain will be inflamed, tired and unhappy. If your gut is experiencing some imbalance, your brain will feel it and act accordingly. Energy is a direct feeling of being energized and alert is a direct reflection of what’s happening in your gut so much so that I tell this story of a study where they took schizophrenic mice and they transplanted those mice the gut bacteria from those mice into mice that did not have schizophrenic traits at all. They did nothing else. No change in medication or brain cells. They changed the microbiome.

The normal mice that received the schizophrenic bacterium became schizophrenic. It’s illustrative of how what’s happening in our gut is what’s happening in our brain and vice versa. We think of it as two completely separate entities, but it’s one entity. This gut-brain access is one that is starting to get a lot more attention over the last few years. To me, now I understand it is connected in the way that a tree is connected to its branches and leaves.

It’s not two separate things with peripheral nerve cells. I realized that it was like a tree. The base is the gut and the top is the brain. It’s one entity. When you are eating or not eating well, your brain will reflect that. You might not be able to think as clear on a day after you ate poorly. Brain fog, fatigue and bloating all go together. It goes to show that we treat energy as something that we need to deal with in our brain, but this is something that we need to deal with as a full-body overhaul+.

All healing starts in the gut time and time again. It sounds so cliché, but it is. As you mentioned, these fecal transplant studies that continue to come out are so incredible every single time. I’m continually mind blown by the results that they find.

HHS 17 | Intermittent Fasting
Intermittent Fasting: The world has become so industrialized that fiber has been separated from fruits and vegetables just to make them easier to digest.

It’s literally mind-blowing and transformational to what you can do to your body.

It’s weight loss, weight gain, depression and anxiety. It’s on every single level by assessing the gut and impacting the gut alone.

It’s in its infancy.

What are some ways that you suggest to your patients to improve upon their microbiome? We want to get rid of some processed foods and clean up the diet altogether, but how would you get patients started?

The first thing if you were going to do nothing else, do the circadian fasting that we already talked about. Giving your bacteria time to sleep and do their restorative repair functions because they have circadian rhythms, too and they live in our body. These critters that live in our gut have personalities and they have food interests and tastes that they like and love to eat fiber. They love to eat, especially prebiotic fiber, which I’ll get into what that is but all fiber.

What that means is when we became industrialized and richer as an industrialized world, we started to separate the fiber from the fruit and the fiber from the vegetables to make it easier to digest. What ended up happening was bread became completely devoid of fiber and juices were much more popular than eating the fruit. Vegetables were too much to chew, so you ended up not using them at all.

What happened is 97% of Americans stopped eating fiber. That’s the amount of Americans that don’t eat adequate levels of fiber. We think it’s convenient because now we can eat faster. Our bodies can digest it faster, but we had no idea what a detriment it was going to be to that gut-brain axis. If you do nothing else, circadian fasting. If you do something second, it would be to overhaul your diet to include fiber. That goes hand in hand with removing the process on ultra-refined foods because those are the foods that the fiber is taken out. You would never find a tree full of sugar cubes or sugar in the wild. You would find fruit and fruit is great because it has fiber, which balances out the insulin spike.

We have created a world where we are starving these beautiful gut bacteria that are the armies for our bodies. These gut bacteria carry these so-called walkie-talkies where they communicate with the rest of our body about what’s going on. They communicate with the brain and the immune system and the hormone system. When they’re starved and very low in numbers, it’s like you have a fraction of your practice working on a particular day, for example, or a fraction of your company working. It’s like, mistakes happen, things go wrong and we wonder why we’re dealing with an inflammatory disease at rates we never saw before.

You then wind up feeling so fatigued. When are we going to stop messing with nature? When are we going to learn?

The best heart health comes from mind and body health. It’s not just about what you eat or put into your body.

What I realized is it’s like medications. I saw another study about how a medication that we often use in Alzheimer’s patients for agitation called mirtazapine. Not only was it shown that it doesn’t have an actual effect. It’s shown to cause death in many of these Alzheimer’s patients. It shows to me that in modern times, everything comes with side effects. Everything that’s not natural or found on this earth is going to have side effects. If you decide, “We want to separate the fiber from food. It’s so convenient. How awesome. We’ve made so many strides,” but we moved backward in many ways. Having that insight that, “Maybe we need to do some more research before we keep doing things that are destructive to our bodies and our planet.”

When in doubt, I always suggest to patients like, “Is it evolutionarily appropriate would we have been doing this as an evolution of species?” If it’s not evolutionarily appropriate, it might not do best for us. It might not be in our best interests. Another question I have for you is, when people are getting to these longer fast, if they’re coming out of the starting point and they’re getting to this twelve-hour fast or maybe they’re getting to a 16 or 18 hour, what are some foods that you would suggest to break those fast?

You don’t want to break your fast with foods easily consumed without fiber that your blood sugar and your brain take a while to register. By the time it registers, you probably ate a whole pizza already. We have all experienced this when you inadvertently fast. For example, when you’re in college or in your young years and starving, you go for these very high glycemic index foods. I’ll take a pizza, for example. I’ll say you eat and your brain doesn’t even register that you ate it for about twenty minutes after you started eating, but you have consumed thousands of calories by that time. That’s not the best way to break a fast. In fact, that’s the worst way to break a fast.

What you want to do is you want to keep in mind that your body takes about 20 to 30 minutes to register. You might want to start with something very small to have easier digestion into it and give your body the same signal like, “It’s time to wake up digestion.” It’s the equivalent of bolting out of bed and starting to run. You might want to take a few minutes even to get your body set. I usually break my fast with a chai. I like chai because tea combined with spices is one of the most healing foods on the planet. When you look at longevity studies, tea has high amounts of polyphenols and if you mix it with cinnamon, cardamom, ginger, and black pepper, these are things that were created to Ayurveda heal bodies.

Now, we’re finding out thousands of years later that these are the most anti-inflammatory beneficial spices that you could be having and you can literally have it in a tea. You don’t want to be putting tons of sugar in it like a lot of people do if they’re getting it from Starbucks or whatever. You want to do a sugar-free or a low-sugar version. I usually break it with something like berries and nuts or a scramble or a smoothie. Usually, I’m now getting ready and rushing to work by the time I finish my fasted workout. I can’t be eating like a full, huge meal. I usually have something light and small until lunchtime.

To give you concrete specifics for someone who might want to try this. Let’s say you stopped eating around 7:30 PM, ideally the night before. You go to bed around 10:00, so you’ll have a good 2 to 3 hours before bed with no significant food. You can have tea and coffee and a little bit of here and there. You wake up in the morning and drink your water. You’re allowed to have any like black tea or coffee. You go for a fasted workout and that might already be 9:30 or it may be somewhere around there and you shower or whatever. You’re breaking your fast around 9:30 or 10:00, giving you a full 14, 14.5 hours of fasting. When I do that, if it’s like 9:30, 10:00, 10:30, I’m usually eating something small to hold me over until lunch. That’s where the tea, the berries, the nuts or something that’s lower sugar, higher fiber and ritualistic is helpful.

It’s getting into a good pattern. Amy, I always like to remind patients that if they become more metabolically flexible, they won’t become hungry between meals or wake up shaky.

I think that the metabolic flexibility piece is interesting because it automatically happens when you start intermittent fasting. You cannot intermittent fast when you live on an every two-hour sugar rollercoaster. You will already find that even fasting 12 hours is impossible in that situation. You have to start changing the way you eat and the contents of food that you eat to even be able to do an overnight fast.

HHS 17 | Intermittent Fasting
Intermittent Fasting: Everything that is not natural on this earth will most likely incur side effects when consumed.

If you’re reaching for a bagel or a granola bar or a bowl of pasta or some carbohydrate-rich meal frequently, you will crash and become hangry. If you start to be able to stretch that out, you’ll feel more energy and improve your gut healing and so on and so forth. We have so much great information from you. I have one last question for you that we ask all of our interviewees before we get to where our audience can find more about you. How do you live a heart-healthy lifestyle?

In the spirit of this conversation, I believe that the best heart health comes from brain and body health. It’s not about what you eat and what you’re putting into your body. It’s the other things you’re putting into your body. What are you thinking? Are you dealing with your stress and what’s going on in your mind and your heart and the non-food aspects of health, which are so overlooked. I was talking to multiple people about how heart health, in particular, gets affected by brain and stress-related disorders. We need to put more focus on daily lifestyle habits that help you distress like nature time, adequate sleep and building in some mindfulness. That’s how I keep my heart healthy.

Also, thinking holistically. Not only the heart, a whole lifestyle. You’re a mother or brother or whatever. You’re this whole person and we have to address that and the mentality surrounding that. Dr. Amy, where can our audience find more about you? Where can we buy your book, all of the things?

My book is available on Amazon. It is available on Kindle. I read it on Audible, if you like audiobooks and the library, all of that stuff. If you can’t afford it or if you aren’t sure, you can check it out from your library. You can find me at and that’s my website. My social media handle on Instagram is @FastingMD or on Twitter, @AmyShahMD and on Facebook, it’s Amy Shah, MD as well.

Thank you so much. I suggest everybody go out and grab the book. Give Dr. Amy a follow online. She shares very actionable items every day and it’s been a privilege to follow your journey and a privilege to have you on our show.

Thank you so much for having me. I appreciate it.

Have a wonderful rest of your day and thank you for reading this episode.

About Amy Shah

HHS 17 | Intermittent Fasting
Amy Shah, M.D., is double board-certified medical doctor and wellness expert specializing in food allergies, hormones and gut health.
With training from Cornell, Harvard and Columbia – She helps busy people transform their health using cutting edge nutritional and medical science. Her proven techniques to heal inflammation utilize the power of the microbiome to help digestion, obtain natural hormone balance and heal food sensitivities. In addition to Dr. Shah’s clinical work, she has written the book called “I’m So Effing Tired” and created where she is especially well known as an expert on intermittent fasting for women.

About Dr. Keith Smigiel NP, DC

Dr. Keith Smigiel

Dr. Keith Smigiel is a regenerative medicine physician and pain management specialist. He takes an integrative approach to medicine, focusing on customized solutions tailored to individual needs. Using advanced, non-surgical treatments, Dr. Smigiel stimulates your body’s ability to naturally heal itself.

Dr. Smigiel helps people suffering from conditions such as chronic pain and erectile dysfunction, to hair loss and weight gain. Combining treatments such as PRP Therapy, Ozone, Neural Prolotherapy, and IV Infusions with functional rehabilitation, he helps you look and feel better.

He heals the body, instead of just treating the symptoms!

With his professional qualifications as a certified family nurse practitioner, a doctor of chiropractic, and a fellow of the International Academy of Medical Acupuncture, Dr. Smigiel offers patients comprehensive care from a broad perspective of conventional and alternative medicine. He also has extensive experience in functional rehabilitation and chronic pain management.

Dr. Smigiel is married to Angela and has two children, Sophia and Larz. When he’s not busy helping patients, he enjoys hiking, mountain biking, motocross, and boating.

About Dr. James Kneller, M.D., Ph.D., FHRS

Dr. James Kneller, M.D., Ph.D., FHRS

Dr. James Kneller is one of the nation’s leading heart rhythm specialists. Dr. Kneller is certified by the American Board of Internal Medicine (ABIM) in Clinical Cardiac Electrophysiology, Cardiovascular Disease, and Internal Medicine.

As a Fellow of the Heart Rhythm Society (FHRS) and Certified Cardiac Device Specialist (CCDS), Kneller provides comprehensive patient care, combining best medical practice with invasive procedures using state-of-the-art technologies to treat heart rhythm disorders.

Beyond guideline-directed therapies, Kneller is passionate about optimized personal health. With a deep interest in complimentary alternative medicine (CAM), he strives to reduce the need for pharmaceuticals, invasive procedures, and exposure to harmful radiation. With Natural Heart Doctor, he strives to help each and every client to Live Well, Eat Well, and Think Well to attain their 100-year heart!

About Dr. Lauren Lattanza NMD, FACC

Dr. Lattanza Office Visit with Patient

As a Naturopathic Physician, I am trained to treat the whole person and get to the root cause of disease.

I went to Arizona State University where I graduated with a bachelor’s degree in psychology with a depth in physiology and minor in Spanish. After my undergraduate degree I was working on prerequisite classes towards medical school, which is when I came to learn that my values identified best with the principles of naturopathic medicine. I knew that I wanted to help patients identify the causes of disease and be able to offer treatments which would improve their health rather than simply treating symptoms.

I dedicated the next 4 years to the Southwest College of Naturopathic Medicine in Tempe, Arizona where I attained my Doctorate of Naturopathic Medicine. I served as Class President all 4 years, Board of Trustees – Student Trustee, spoke as the Club President for our branch of Toastmasters, and was voted by my peers and attending physicians to earn the Outstanding Leadership Award for the Class of 2020. Throughout medical school I took it upon myself to work alongside MDs, DOs, chiropractors, and functional medicine practitioners in addition to naturopathic physicians.

As a Spanish speaking student, I was able to volunteer with community clinics around Phoenix and provide free healthcare to low-income families. Due to this combined exposure, I came to find my passion in treating cardiometabolic and digestive disorders that are all too common, yet largely preventable. I took the opportunity to learn the broad spectrum of healthcare so I can ensure that I am able to provide my patients with the best options.

About Dr. Jack Wolfson DO, FACC

Dr. Wolfson Office Visit with Patient

Dr. Jack Wolfson is a board-certified cardiologist, Amazon best-selling author, husband, father, and the nation’s #1 Natural Heart Doctor.

For more than two decades, more than one million people have enjoyed the warmth, compassion, and transformational power of his natural heart health courses and events.

Dr. Wolfson is the founder of Natural Heart Doctor Scottsdale, his heart health practice in Arizona, and Natural Heart Doctor, an online resource center with natural health information. Doctors from across the globe reach out to Dr. Wolfson for training and education in holistic health practices.

He has been named one of America’s Top Functional Medicine Doctors and is a five-time winner of the Natural Choice Awards as a holistic M.D. Dr. Wolfson’s work has been covered by more than 100 media outlets, including NBC, CNN, and the Washington Post. His book “The Paleo Cardiologist: The Natural Way to Heart Health” was an Amazon #1 best-seller.

Dr. Wolfson and his wife Heather have four children and are committed to making the world a better place to live. They provide for those in need (including animals) and support natural health causes through their philanthropic efforts.


Our chiropractor is an expert at adjustments and holistic chiropractic care and works closely in conjunction with the other health care experts at Natural Heart Doctor.

Call (480) 535-6844 for details and scheduling.

IV Therapy

We use specially formulated natural vitamins and minerals that are injected into a vein to prevent or treat dehydration. Ideal for people in Arizona.

Call (480) 535-6844 for details and scheduling.


Stimulate your body’s natural healing abilities and promote physical and emotional well-being with acupuncture at Natural Heart Doctor.

Call (480) 535-6844 for details and scheduling.

Health Coaching

Our health coaches use evidence based skillful conversation, clinical interventions, and strategies to engage you actively and safely in health behavior changes.

Call (480) 535-6844 for details and scheduling.

Cardio Tests

We use the most advanced testing in the world to assess heart health and to identify the root cause of your health issues.

Call (480) 535-6844 for details and scheduling.

Office Visits

Schedule an office visit with one of our cardiologists, holistic physicians, chiropractor, or health coaches.

Call (480) 535-6844 for details and scheduling.

Frequently Asked Questions

I’d like to receive an online second opinion from Natural Heart Doctor. What do I do next?

You can initiate a second opinion online through our website at any time. To begin, select the team member you’d like to speak with and open an account.

Click here for cardiologist Dr. Jack Wolfson.

Naturopathic Medical Doctor Dr. Lauren Lattanza. Get details.

Naturopathic Medical Doctor Dr. Tonia Rainier. Get details.

Click here for  Natural Heart Doctor Health Coach.

Alternatively, you can email A member of our care team will help guide you through the process of starting a second opinion.

What is the cost of a Natural Heart Doctor Online Second Opinion?

The cost for most second opinions varies by team member. This fee includes information collection, a phone or video consultation, a second opinion from a Natural Heart Doctor specialist and guidance throughout the process from your personal Care Team at Natural Heart Doctor.

Cardiologist Dr. Jack Wolfson’s Second Opinion Fee is $1500.

Holistic Physician’s Dr. Lauren Lattanza’s Second Opinion Fee is $250.

Naturopathic Physician Dr. Tonia Rainier’s Second Opinion Fee is $250.

Note: We apply the Online Second Opinion Call fee as a credit to any future consultations with Natural Heart Doctor, should you choose them.

Will my insurance cover the cost of a Natural Heart Doctor Online Second Opinion?

Most likely, no. Most health plans do not cover online second opinions or consultations. You are responsible for the cost of our second opinion. Natural Heart Doctor cannot file a claim with your insurance carrier, nor can we provide a procedure (CPT) code for this service.

What is the timeline to receive an online second opinion?

We do our best to schedule your second opinion as quickly as possible. Typically, it takes 5 to 7 business days after your information has been collected to receive your phone or video online second opinion.

What information do you need in advance of our call?

Our office will send you a short questionnaire to complete and return. We DO NOT need your complete medical records.

How many questions can I ask the expert during our call?

You may ask a maximum of five questions. This is to ensure that the expert has sufficient time to devote to each question. All questions must be finalized before your online meeting.

What should I expect to receive once my second opinion is complete?

You will receive a summary of our discussion along with our second opinion. The second opinion will be in written form. After you have reviewed the second opinion, a Natural Heart Doctor clinician will follow up with you by phone to address general medical questions about the information provided in the second opinion.

What if I have follow-up questions for the expert after I have reviewed my second opinion?

If you have a clarifying question about an expert’s response to one of the questions in your second opinion, and the Natural Heart Doctor clinician is unable to address it, then you may request a follow up session for an additional fee. 

Is my medical and payment information secure?

Natural Heart Doctor is strongly committed to protecting the privacy and security of all our patients. Our website meets all federal requirements for protecting personal health information under the Health Insurance Portability and Accountability Act (HIPAA). All financial transactions are processed by Natural Heart Doctor securely using industry standard payment processing tools.

I would rather visit Natural Heart Doctor for an in-person appointment. What should I do next?

If you would prefer an in-person appointment at Natural Heart Doctor instead of an online second opinion, please call (480) 535-6844 for details and scheduling.

Can I schedule a follow up appointment with the specialist who provided my online second opinion?

Yes, we’re happy to help you on an extended basis. Our clinician can discuss options with you when presenting our second opinion summary.