Episode 85 | Dr. Felice Gersh, M.D. | A Complete Guide to Time-Restricted Eating

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On today’s NEW podcast episode Dr. Felice Gersh, M.D. we’re focusing on time-restricted eating. It’s a nutritional approach that’s not about what you eat, but when you eat.

What is time-restricted eating? It means a person eats all their meals and snacks within a particular window of time each day. Outside that window, a person consumes no calories. It’s a type of intermittent fasting that has become popular in the recent years. And by the way, intermittent fasting refers to any eating plan that alternates between periods restricting caries and then eating normally.

By the way, intermittent fasting is a way to boost weight loss, lengthen lifespan, reduce insulin resistance, improve heart health and have positive effects on your immunity.

I get a lot of questions on time-restricted eating. Is it effective, is it safe, what’s the best approach for women, and do the benefits vary based on your age?

That’s why I’m delighted to have Dr. Felice Gersh, M.D. on the show today. I had the privilege of meeting Felice at the A4M conference in Las Vegas a few years ago. She has a brilliant mind, is an incredible speaker, is passionate about holistic women’s healthcare, and she’s a leader in this discussion of intermittent fasting.

She’s an award-winning physician, a board-certified gynecologist, and obstetrician, also trained in integrative medicine. She received her undergraduate degree from Princeton, and her medical degree from USC School of Medicine.

On today’s show, you’ll discover…

• Time-restricted isn’t a miracle weight loss cure, but how can it impact your lifespan, insulin resistance, and heart health?

• There are different windows of time to go without eating… 10-hour, 12 hour, and even a 16-hour fasting window. Is there a sweet spot… and what is it, specifically for women?

• Since with time-restricted eating, you haven’t had food for some period of time, that first meal is important. What is an optimal way to refuel the next day?

Connect With Dr. Felice Gersh, M.D.

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Kathy Smith: Felice, thank you so much for being on the show.

Felice Gersh: Oh, it’s my pleasure. And I just love this topic. I’m so glad that you have brought this to the attention of everyone.

Kathy Smith: Okay. So I think that even though you might talk about this a lot in the different circles you’re in, I think we should just get back to some of the basics and overview of time-restricted eating and really how has it evolved?

Felice Gersh: Well, it’s a fascinating new understanding of life. Really, every life form on this planet, we all evolved to live on this planet. I know I love science fiction, the idea of traveling to other worlds. But really, we evolved with the 24-hour rotation of our planet earth. And because of that, to optimize survival, we are very different creatures. Some of us, like humans are diurnal, so we’re very different. We like to be active during the day compared to bats, which are nocturnal and function more and are active at night.

So based on that, we have very different metabolic systems. Our immune systems are very different based on the time of the day so that we have this amazing clock in our brain that sits atop the optic nerve and has sensors that connect directly with the retina of the eye to sense light and dark. And we also have some nutrient sensors that also gives them added information so that this part of the brain – the master clock – can actually know what time of day it is to, then, put out signals to control all the other organs in the body to work in this beautiful synchrony of function.

Well we didn’t know any of this until just about 20 or so years ago. And so now that we know it, we understand like you said at the beginning. It’s not just what you eat– although that’s really important– but it’s also when you eat.

So with our new evolving understanding of circadian rhythm, which like I said, every living creature on this planet has clock genes and actually regulates it according to the rotation of earth. We now know that or body’s metabolic functions are highly regulated by this clock. And when the body receives food, it’s going to dictate how well it functions.

Kathy Smith: And so this master clock that we all have dictates all this. And yet, with this time-restricted eating, from what I’ve read, there are different windows. There’s an eight-hour window of eating, there’s a 10-hour, there’s a 12-hour – different windows of eating. What is the sweet spot for anyone in particular and then, specifically, for women? Or is there a sweet spot?

Felice Gersh: Well there’s limited data. But based on what we have and as you probably are well aware, most research has not been on women. And most research has been involving men. Because men are simpler to work with because they don’t have to deal with menopause and pregnancy and birth control and that sort of thing. So until five years ago, no studies actually had to discriminate whether they involved women or not. So we have limited data.

But based on what we have, I would say that every woman should strive for a fasting window of 13 hours. And it’s not just any window of 13 hours. It would from dinner to breakfast. So basically, since we are diurnal (we are day creatures), we are really designed to sleep and to fast at night. So that’s where I love to discuss more about this whole concept that got out there that you should fast through the first half of the day. That’s really not how we’re programmed.

So we have, like what I mentioned the master clock, but it turns out that about one-third of all the genes in every cell are actually clock genes. And even the ones that aren’t, actually interplay with. So about 90% of all the genes in our body have some relationship to clock genes. So we really have to recognize that we are what we are. It’s programmed into us– it’s not mutable– that we are programmed to function best if we sleep at night and we don’t eat at night. And we function during the day. We’re active and we actually eat during the day, but not constantly. That’s the other thing is that we now know that incessant daytime eating where we have no fasting window during the day is also bad, which we can cover because we want to have this big stretch of fasting at night. Then we want to have little stretches of fasting during the day.

Kathy Smith: Okay. So let’s think about this 13-hour window. And if you picture the clock, which I am right now, let’s say that my last meal is at 8:00 at night. Then what you’re saying is that I’m going to fast until 9:00 the next morning. And that would give me 13 hours of fasting right there. And is that kind of the window you’re looking for?

Felice Gersh: That would be, I would say, at the very tail end of okay. Because it turns out that because we are so programmed between day and night and our differentials and our metabolic functions, 8:00 at night would be really the very latest that you’d want to eat. And if you could move it up a little bit, that would be better.

Kathy Smith: Oh, Felice, Felice. Don’t tell me this.

Felice Gersh: I said I’m accepting it.

Kathy Smith: Okay. So 10:00 is way out of the question, then, is what you’re saying.

Felice Gersh: Here’s the thing. Humans, it’s really important to know that– it’s amazing. Think about homo sapiens. We’re not very big. We’re not very powerful. We don’t have fur. We don’t have claws or anything. How come we didn’t become extinct? It’s because we are so adaptable. So I’m giving you what I’ll call optimal. But we humans are adaptable, so we can get away with a lot. Okay? By the way, if you do the same thing every day, that actually helps to program not just your own cells but your gut microbiome cells.

It turns out the microbes– every living creature like I said has clock genes, including the gut microbiome. And they can get programmed to sort of anticipate when food comes in if you do it the same time every day. So I’m not in favor of eating every night at 10:00 at night. But if you did it seven days a week, and then you actually did fast and you got adequate sleep for seven/eight hours and then you fasted for 13 hours and you did the same thing every day, your body would adapt to that. Even if it’s not optimal, you would adapt to it. But it would be worse if you jumped all over the time zone every single day.

Kathy Smith: Got it. So let’s back up then. Because I kind of cut you off there. What would be optimal? You said that optimal– I guess you’re saying until 6:00 at night? What’s the optimal window?

Felice Gersh: Yes. I would say until 6:00 at night. Like if you ate dinner and finished at 6:00 and then you had breakfast between 7:00 and 8:00 the next morning, that would be ideal.

Now say you can’t. I always give people outs, okay? I never want this to be the enemy of better. So I always give people a few outs if they just can’t live with such things.

Kathy Smith: Well the interesting thing is, it’s a throwback to when I was growing up. I mean, my father was in the military. He’d come home from work. At about 5:30, my mom and I, my sister, we’d all be prepping for dinner, setting the table. We’d sit down a little before 6:00 and washing dishes, like, at 6:30. And then, the next morning, we’d be heading off to school and that’s kind of the breakfast scenario that would be happening in the morning.

But through the years typically social, going out, or a reservation for dinner night starts at 7:30, let’s say. And you’re eating until 9:00/9:30 type of thing. You’re flying, you’re working, you’re doing business meals, all those things. But disregard even that, I feel like we are all eating a little later. And I’m like– this is going to be my own therapy with you, because I have pushed my eating too late at night. And I snack a little bit too much.

So I like you’re saying that the ideal is between that 9:00 and 6:00 type of thing. You’ll accept maybe the 10:00 to 8:00 kind of window – or 11:00 to 8:00. But you’re trying to push it so you’re not going to bed with a full stomach. Why is it so bad to go to bed with a full stomach besides the obvious that maybe indigestion? Why is it so bad?

Felice Gersh: The indigestion is actually a reflection of what I’m going to tell you. Our gut is also on the clock, so no one should be, like, going to the bathroom, having bowel movements in the middle of the night. Our gut should be resting.

So our gut is on the clock too. So everything should be different between day and night. We should be restoring ourselves and healing at night, not actively digesting. And it changes everything – the way the body works when you try to get the food to actively be digesting at night. It doesn’t want to do it. That’s why people get so much heartburn when they eat at night. Because they’re enteric nervous system (the neurological system) of their gut is not programmed to be active at that time of day. And we become very insulin resistant at night. So it takes a lot more insulin to be produced to get the blood sugar that’s going to rise after we eat to get that glucose into the cells. Our insulin level is going to be jumping up really high because we’re insulin resistant at night. That’s why night eating is such a problem.

And we now know we have this other system called the endocannabinoid system. It’s a system of lipids or fat mediators. And that is also very, very circadian. It’s shown that people who eat at night, they will actually have dysregulation of this system. And this system regulates our immune system, our mood, and our cravings, like our appetite. So people who eat late at night will have indigestion and their GI tract isn’t working well. They’ll have more tendency towards insulin resistance, more pushing towards developing prediabetes and diabetes. They’re even going to have more mood disorders and cravings because their endocannabinoid system is going to become dysregulated.

So it is a problem. But it’s, like I said, the biggest problem is if you are doing it on an intermittent basis. The more you do everything consistently– that’s not saying that you should eat junk every night. But you can actually shift your circadian rhythm somewhat if, basically, you’re living in a different time zone.

The problem is people aren’t taking everything out of their lives, and they’re living in a different time zone. You’re living across multiple time zones, so they’re eating like they’re in one time zone. But then, they’re working like they’re in the other time zone. And that just doesn’t work with any of our systems in our body. So it’s really like the accelerated pathway to early aging. It’s really going to stress every system in the body.

Kathy Smith: So when it comes to time-restricted eating, it sounds like this is a style of eating, a method of eating that you recommend for most women out there. We’ll get to people you don’t recommend it for, but two questions. Do you recommend it daily? And secondly, and probably the bigger one, why are you recommending this? Now I know a lot of people say, “I’m going to be able to lose some weight. This is the best weight-loss method.” And yet, honestly, from what I’ve read, it isn’t necessarily a miracle weight loss cure; although, you can lose weight on it. But there’s all these other benefits. Can you describe those?

Felice Gersh: Sure. Well when it comes to women, women have much more difficulty losing weight. We are programmed to hold on to our fat, because we’re the ones that were programmed to keep the fat so that if we become pregnant, we’ll have a storage of energy and to nurse babies. So women are designed quite differently than men. So never compare weight loss between women and men.

So I try to not talk so much and focus on weight loss. I try to focus, like you just mentioned, on health. And then I say, “The weight will sort of come around as you get healthier.”

So once you realize that our immune system is programmed by the clock, and our metabolic system, then everything in the body will be optimally functioning. The most important thing to start with is the idea of insulin sensitivity.

It turns out that the way that we process glucose in our blood. which is the key form of energy. Okay, the preferred form of energy is glucose. And the way that we process it is very different between the early part of the day, the later part of the day, and the middle of the night. So if we consume most of our food in the first part of the day, we are most insulin sensitive. That means it takes less insulin to get the glucose from in the blood stream where it gets after it comes from the gut and gets digested into the cells, which need it.

The cells love glucose. It’s how they create energy, and everybody wants to have energy. And in order to get that, you need to have the insulin help to transport it through the insulin receptor. But if the insulin isn’t working very well, then the body will make more and more amounts of insulin.

Well the more insulin you have, the more fat you’re going to make. It turns out that we women like to think we’re multitaskers, but we cannot do them both. We cannot burn fat and make fat at the same time. It’s one or the other. And when you have higher levels of insulin, you cannot burn fat. You can only make and store fat.

So if you eat your food earlier in the day when you’re most insulin sensitive, you’re insulin level will not rise as high. And then, it will come back to the normal level. You won’t have like a big spike. You’ll just have maybe a little bitty bump up. And that will allow your body to burn fat instead of constantly just store it and set.

If you eat incessantly– say you just snack all day long– it wasn’t that many years ago that everyone was advocating for this grazing thing. Like you should be eating every two hours to maintain your blood sugar. When you think about that, it’s really crazy. It’s like can you imagine humans evolved if they could only function if they ate every two hours? Where would all that food come from?

So that is not how we were programmed. We’re not in any way at any time in our history needing to eat every two hours. But if you do eat constantly, or you’re sipping a sugar-laden drink, which a lot of people have on their desk, and they’re just drinking the sugar thing all day long, they will always have higher levels of glucose and then higher levels of insulin. And then you can never get into fat burning.

You can only burn fat when you’re fasting. Okay? You have to get that insulin down. So that’s why I like the idea that you have little fasts during the day and a big fast at night so that you can have your insulin down and you can actually go into restorative and fat-burning mode.

So you have to eat preferably. Now this is ideal. I know most people won’t do it. But eat a good part of your food for the entire day when you’re most insulin sensitive, which is in the first part of the day, preferably within a couple of hours of waking up if that’s doable. And then not eating during the day. Maybe he’s skipping lunch and then having your nice medium-sized early dinner.

Now say that doesn’t work for you. Well you can have a snack for lunch and call it a light lunch. But try to keep it foods that will not raise your insulin level, which is fat.

So I’m not into ketogenic diets. That’s another whole topic. Because I love fiber, which comes in plants and whole grains and such. But if you eat a fatty snack and you call it a light lunch, then really, you’re not going to raise your insulin level. And the idea is to keep your insulin level as low as possible in the normal low range through much of the day so that you can actually even get into a fat-burning state during the day.

What you don’t want to do is keep that insulin up high. And that’s why we have an epidemic of diabetes and prediabetes in our country is this incessant eating during the day, and then late at night, you never get your insulin level down. You’re never going to be metabolically healthy. And when you have high levels of insulin and high levels of sugar that often, then, go along with it, it promotes inflammation.

Inflammation underlies, basically, everything bad in the body like neuroinflammation that leads to dementia, Parkinson’s, and such. And inflammation in our arteries, which takes you down the path of atherosclerosis, heart attacks, and strokes.

So we want to keep our insulin down. That helps keep our inflammation down. And as well, when we eat only periodically and we eat according to our circadian rhythm, we help to nurture our critically important gut microbiome – those trillions of microbes that reside in our intestinal tract – that actually turn out to be modulators of also everything in our body. We didn’t realize that. The control center was really in our gut.

Those little critters need to be fed at regular intervals and fed the right food, so we need to recognize their critical importance. We didn’t know anything about them until relatively recently either. And they have to be fed on the clock as well.

Kathy Smith: Right. I had Zach Bush on the show talking about the gut. And since that time, again, getting so many questions about what are those right foods. He talks a lot about plants and making sure that you have plants throughout the day.

But why don’t you give us a typical day of eating in your world or a recommendation? We need a good meal two hours after we wake up. Then we either have a fat-based or light lunch, no lunch, fat-based lunch, and then a light dinner. So do you want to describe those three meals to me so we can get an idea of what you’re talking about?

Felice Gersh: Sure. Now what I’m going to say probably is not going to sound appealing to a lot of people right now. But you have to sort of change your whole notion of what breakfast is. So I just call it morning meal. Because breakfast has all these connotations of certain types of food. And then I want to sort of take away.

I love to start a day– like I said, this may not appeal to everyone yet– with – I call it the breakfast salad. It’s a big salad, and it has all kinds of vegetables in it. Some of them are steamed, but now they’re cold. I like to steam broccoli and cauliflower, but then, I put it cold into the salad. And I put in beans and nuts and seeds, and I usually cut up some kind of fruit like a lot of strawberries, sometimes blueberries or little pieces of apple. Occasionally, I’ll put in a little bit of chicken– some free-range chicken that we have– just little bits. And I usually use a nice vinegar and then sometimes a little bit of olive oil, sometimes not.

It’s so filling and it takes so long to eat. You have to chew it. That’s the biggest problem. You have to allow more time in the morning, because a salad takes so long to eat. Sometimes I have to take it with me and eat on a little break after I get to work, because it takes so long to eat that salad. But that’s my favorite breakfast actually is breakfast salad.

But sometimes I just eat left overs from dinner. I make tons of different vegetables. It’s just an array of random left-over vegetables – usually like yams, sometimes a cold potato. Cold potatoes by the way are– you probably have talked about this– they’re resistant starch. So they’re actually pure food for the gut (microbiome), but they don’t raise your blood sugar at all. So I’ll have a little cold potato salad with vinaigrette dressing, and I will have left-over broccoli, and we usually have bean salad. So we have all these different random things in my refrigerator.

They’re all prepared ahead. So I’m not cooking anything in the morning. Everything, I prepare the night before. It would be better to make your salad fresh, but I’m a realist. I’m not going to do that, so I just make it the night before and all these other things are just in the refrigerator. I don’t have a problem eating things cold. But you can always heat them up, and that takes just a minute.

So basically, it’s like dinner for breakfast. Okay?

And then for lunch, I typically have what is a Fast Bar. A Fast Bar is like a nut bar. I think it’s really delicious and filling. They come in different flavors. They’re made by a company L-Nutra, which I actually work with. I’m one of their medical advisors and speakers. That’s how I got to know about it. They call it a Fast Bar. So I consider it a fasting substitute.

I would prefer not to eat anything for lunch, but I really like to have something. So I usually have a big mug of tea and then I have my Fast Bar. And that holds me until dinner.

Then dinner is usually a lot of vegetables and beans. And I usually allow myself three ounces of animal protein a day. Sometimes I have it with breakfast, and sometimes I have it with dinner. So it would be like the equivalent of a little chicken thigh or a drumstick or some sardines or a small piece of wild salmon, something like that. And then just a whole array of vegetables. I just love roasted vegetables. I’m fortunate that my husband is a fabulous cook, because I am not. I love eating, and I do wash the dishes. But he makes great cauliflower rice and all kinds of bean dishes and lentils and roasted vegetables, different dishes with cabbage. So it’s great to just experiment and get cookbooks and learn how to enjoy vegetables.

When I grew up, it was the opposite. I didn’t like vegetables, because my mom– unfortunately, I learned how to cook from her. That’s why I’m not the designated cook. She kind of made every vegetable into a soggy mess. They were mushy.

Kathy Smith: Soft and mushy. I know. I remember those.

Felice Gersh: Yeah. Oh, my god. That’s what I grew up with. So I was like, “Why would anyone want vegetables?”

But you just have to learn that they don’t have to taste like that. They have wonderful ways that they can be prepared and very creative. There are many cultures in the world that use spices that you probably have never even tried– and working with new and creative ways with spices. It’s really looking at food from a different perspective. It’s not just entertainment, which most people think of food as entertainment. But it’s really the nourishment that keeps every cell in our body working optimally.

So we want to find creative ways to love our food but really have the food that will provide what our body really needs. That has been such a discordance between the necessities of what food is to provide for the body and the way that we have, as a society, been consuming food without any regard for what our bodies really need. We just have to get it out of our minds. We have to do this so–

Kathy Smith: But Felice, as you’re saying that, there are three things that are coming to mind. One is– and I want to touch on all three of these ideas. I feel that there’s an adaptation process kind of like working out. When you first start, it feels foreign to your body, and eventually, as you get into it, you start to crave it. It becomes a lifestyle. And then you feel the benefits, and now, it’s not just the benefits. But you feel the social side, the mental side. It just becomes a really wonderful way of life.

I want to also put out there that through the years since I’ve adapted my eating, I can be social, I can cook the best meals in the neighborhood, I can do all these things. So it doesn’t have to feel like deprivation. I want to put that out there.

But I also want to say a couple of things that you brought up. I’m glad you reminded me, because the Fast Bars, L-Nutro, when I went through their program and I had that Fast Bar, I’m like, “Oh my gosh.” I love that bar. It’s something that I can eat, and it makes me feel satisfied. I get a little bit of sweetness. I feel great. I feel mentally alert. So I’m glad you reminded me to order some of those. So I think that’s great.

The other thing that you reminded of is potatoes and resistance to starches. You’re absolutely right. When I discovered that little nugget, that we can have potato salad. Because, again, being raised in the military and relatives from Wisconsin in the Midwest, there was always potato salad. There was a time when I cut potatoes out, and I love the fact that potatoes are on the list.

But I do want to get into this idea of how we gradually get into these kinds of techniques if you want to try them. Because I realize you’re going down to the absolute best, and I think you pointed out earlier in the discussion, there’s a lot to be said, from what I’ve read, if you want to try this– maybe I’m wrong here now– but if you want to try one day a week, two days a week. If you want to try a shorter span, you start to lengthen it. So I want to talk how you might gradually get into this.

Felice Gersh: I think the first thing is to start regularly eating breakfast, which a lot of people are skipping. So find real food, not the conventional American breakfast food that comes in a box or plastic or something. Find something that you love. It could be baked beans. You can get really delicious baked beans not filled with a lot of sugar. There are some organic companies that make really good baked beans or you could make your own.

Most people like baked beans or a soup like maybe a bean soup or a chili. A lot of people like vegetarian chili. So find something that you like, and then try to start eating it for breakfast. Maybe come up with three or four different items, and just eat breakfast. That’s just a start. You’ll feel so much better. Your appetite– they’ve done so many studies that if you eat breakfast, you’ll be less hungry for the rest of the day. Your metabolic state is going to be revved up. You’re going to be in such a better state.

And it takes maybe a month of eating breakfast every day before your body really adapts to not being so hungry for lunch or late morning snack and such. And then try to switch over so that every snack you have in the day is fat.

The best snack is olives. If people like olives, I say, in the beginning, just eat olives whenever you feel you have to eat. Because that’s not going to have almost any impact on your insulin and blood sugar. And if you can’t just eat olives– some people have a love/hate thing with olives– you can have a couple of macadamia nuts or maybe 1/3 of a Fast Bar. You can take the fast bar, you can divide it over the day so that you’re eating something that helps you to feel satisfied, but you’re not going to raise your blood sugar and insulin.

Because you have to get your body adapted to burning fat. Remember, if your body hasn’t burned fat in a long time, it’s rusty. And you feel starving when your blood sugar starts to go down, and then you start craving food.

So instead of eating something that’s going to raise your blood sugar, eat something that is predominantly fat that will keep your blood sugar and your insulin levels low. Just work on that for a month, and try to eat less and less, the number of snacks during the day.

And just go for three meals a day. Don’t go for the elaborate, mainly two meals. We’ll say that’s more advanced. So just go to try to limit yourself to three meals a day and if you have to snack, keep it something that’s going to keep your blood sugar down, like a few bites of avocado, and then hydrate. A lot of times when people think they’re hungry, they really will feel fine if they just hydrate.

So there are so many wonderful teas on the market. Experiment with different teas. Some of them are very naturally sweet, like rooibos tea and kava kava. They actually have a sweetness– hibiscus tea. So have a lot of teas. Stay hydrated. Eat a little avocado, some macadamia nuts, a piece of a Fast Bar, some olives when you feel you desperately have to snack.

Just try to limit yourself to three meals a day. Do that for a month or two. That alone, is going to get you a long ways towards getting into real-time, time-restricted, more advanced time-restricted eating. But even if that’s where you stay, and you stop eating by 8:00 at night most nights, and you have that breakfast within two hours of awakening, about 13 hours or so after you had dinner, your health will really improve and your emotional health and your mental clarity. Because it’s all linked together. You’ll feel so much better. So you don’t have to achieve the ultimate. Just aim for that for now, and then, see if you want to move into, we’ll say, the more advanced levels.

Kathy Smith: Is there any problem with going longer? You said 13 hours. But what if you went 16 hours? Is there a problem? Is there a point, again, that too much time fasting can impact our hormones or other things in our system?

Felice Gersh: There’s very little data on impact on fertility or a menstrual cycle. There’s very little data on that. I keep looking for more. But in terms of general health, there is little return – maybe a little bit of return on investment once you get above 13 hours. And the 13 hours for women, where did that come from? Primarily, from data on breast cancer and post-menopausal breast cancer survivors, where they show that if you have a 13-hour sweet spot, that there was a lower recurrence of breast cancer in those women.

There’s not a lot of other data on women. But that is, to me, a very good sign, because if you’re keeping cancer down, you’re keeping everything. Because everything links together. So if you can keep breast cancer recurrence down by fasting 13 hours, that seems like a good marker for me.

In terms, of increasing to higher numbers, like 14, 15, 16 hours, that’s okay. I don’t know if there’s a lot of– like I said– return on investment for that effort. But it all has to be on the end, but nobody wants to do that. It has to be on the evening end. So it means that suddenly, when are you going to stop eating? At 4:00 in the afternoon? Because you shouldn’t push out eating in the morning beyond two hours after you get up. You can, because our bodies are so amazingly adaptable, but if you’re trying to do what’s optimal, you don’t want to create that fast where you’re basically not eating during the most insulin-sensitive time of your day when your body is most aligned with eating food to optimize its functioning.

So you don’t want to push not eating into the afternoon and you just missed your most opportune, healthiest time of day to eat. So it’s okay if you want to stop eating at 4:00. I never ask people to do that. I mean, it’s hard enough for me to say to don’t eat after 8:00 at night. I’m not going to say stop eating at 4:00. I’m not going to tell people to do that.

Kathy Smith: I would walk out of your office. It’s like, nice try. So is there anybody that should not be practicing time-restricted eating? Any women out there?

Felice Gersh: Yes. Pregnant women, you are in the lucky state when you can eat healthy food during any time. Children– of course, they’re not adults. But people under the age of 18 are allowed to have healthy snacks. This is not like a free-for-all-you-can-eat-junk-food. It’s that you’re allowed to eat more times during the day.

And I don’t mean you should be eating at night. This is not like you should be eating late at night. But if you’re pregnant and you wanted to have a healthy fat-based snack before bed– like you wanted to have half an avocado or some nuts or seeds, that is okay when you’re pregnant.

The other group would be really frail people – the elderly, the frail. We really don’t have data on people much beyond, let’s say, age 70. I would still not recommend late-night eating. But maybe for people who are elderly or frail, it’s okay for them to eat a snack further in the evening. We need to have more date on the frail and the elderly. But we know that they really need to have more protein in their diet.

So all the advice that I’m giving would really be for healthy people below the age of 65 just because we don’t have the data. That’s true for so many things. There’s so little data on people over the age of 65. People don’t want to do studies on them.

Kathy Smith: We’re working on getting that changed. That’s for sure. But what about exercise and timing of exercise with timing of eating. Is there a plus or minus for exercising before you have your first meal or after?

Felice Gersh: Actually, in terms of weight loss, it has been shown that if you exercise before your first meal of the day and then, you eat within about 30 minutes of completing your exercise, you will build muscle well. And you will actually lose weight better. So there does seem to be something a little bit magical about exercising on a fast in the morning.

And once again, this should be for healthy people. Once again, there’s no data on anybody else. But I think that if people can do that, that is great. There is some data, because of our insulin sensitivity and the time, that if you exercise in the morning, in general, you will tend to lose more weight than if you exercise later in the day. To be honest, I’ll take exercise when anybody will give it to me. Because exercise at any time is better than none. But if you’re going to go for best, then go for when you’re fasting in the morning before breakfast. That would be optimal for overall metabolic state and for weight control.

If you just can’t, then do it later in the day. But optimal seems to be if you exercise on a fast.

Kathy Smith: I know from my own experience that I find this type of approach to eating very liberating. And I’ll tell you why. I don’t feel like I have to eat. I want to eat, and I feel good about eating. But I don’t have those moments anymore where I feel like I’m dying and my blood sugar’s dropping, and I have to have something at 10:00 a.m. or I’m going to bite somebody’s head off or I’m not going to be able to concentrate.

I think that’s been the magic for me – the concentration, the focus, and the loss of cravings. And I think that’s just, as I leave you today, has been one of my big take aways with this approach. And I don’t know if there’s anything that you want to add to that – what you’ve seen with patients, with people that you talk to, any of the a-ha moments about this type of eating.

Felice Gersh: Well 100%, I echo your sentiments. I feel the same way myself, and what I find is that in the beginning– and this is where people have to just sort of hunker down and know that it will take a little while if they’ve been eating sort of randomly all across the time of day, and they’re eating a lot of foods that raise their blood sugar, and then they’re insulin. And then they have these crazy ups and downs of insulin and blood sugar all day long, and then they go into really a hypoglycemic state on and off all day. And then they get tired and then they eat something really very bad that’s going to be a refined carb that’s going to raise their blood sugar, that it just takes time for their bodies to adjust and get into that burning fat mode.

Think of all the mitochondria, rusting and burning fat. They’re just like used to burning the carbs. So you just have to be patient and the tricks are that when you feel like, “Oh, my god. I’m going to die,”– and hear this from my patients. I fortunately, have never had this experience, but I’ve seen it firsthand so many times. I know it is real. They feel like if they don’t eat something, they’re going to die. They’re feeling faint. They’re feeling famished. They’re going to die.

But when that happens, know that this is temporary. If you hydrate with like teas and you have a little something, just a couple of bites of something fatty, like a few olives or some macadamia nuts, a little avocado. If you just do that and hydrate, it will take maybe a month, maybe six weeks, this will pass. And then, what you just described how you feel, that’s how they will feel too. That this is temporary. The body will adjust, so don’t feel bad if you mess up here and there. Just know that you have to stay the course, and you too – every person – can adapt the way your body has adapted, and mine, to have freedom from that feeling of absolutely having to eat for no good reason, and their blood sugar is so poorly maintained because of their insulin sensitivity problems.

But this will pass and everyone can have that same wonderful feeling of eating only when they need to eat and not feeling these terrible, overwhelming urges that they just have to eat and then have crazy cravings.

Those are doable. We can do this. And everyone should know, just be patient. Stay the course. They will get exactly where you are today.

Kathy Smith: Well I love this topic. And I love how well– not only informed, but how well you can give this information, help us understand it. So I thank you for that. Are there any kind of topics or programs or anything you’re doing right now? Do you want send us anywhere to let our audience know what you’re up to?

I know you have a site and you sell certain supplements and such, but is there anything you want to tell the audience at this point?

Felice Gersh: Well I am still very much an old-fashioned doctor. But in my being old-fashioned doctor, I’m newfangled in that I do the telemedicine stuff now so that people anywhere can access me. I always love it if they can come and see me in person, but through telemedicine, I can actually give advice to people everywhere in the country and the world.

They can find me through my website at IntegrativeMGI.com. I’m trying to grow my Instagram, and I’m doing Instagram lives twice a week now on Tuesdays and Fridays. I’m trying to make interesting topics. So I’m getting some letters to the editors and articles out in some mainstream journals. I’ll publish all of that on my Facebook and Instagram so people can see what I’m up to, and hopefully, get some knowledge and education. Because that’s really one of my key missions at this stage of my career is to help people wherever they may be – not just the ones who can come to me in my office, but wherever they may be that they can learn to optimize their health and access their own internal abilities to heal and to stay healthy in this challenging world that we all live in.

Kathy Smith: I think that’s what everybody loves about you, I love about you. It’s one of the things whenever you go to these conferences, Felice’s name is at the top of the list of people who want to hear her speak and want to hear her thoughts on things, because you are so up to date and especially on women’s health from mainstream to integrative. So I appreciate that about you.

I appreciate you being on the show and sharing all of your information, and I look forward to seeing you in person or actually signing up for one of your teleconferences and doing some medical things with you. Because each decade, each year, each decade brings its own new surprises and wonderful things that come along. And I think being informed, informing each other, staying informed about your own body is the key to master aging.

Thank you, Felice, for being on the show. Much love. Can’t wait to have you back.

Felice Gersh: My pleasure.