Fasting, Ketosis, Carbs, and Time-Restricted Feeding Tweaks with Vanessa Spina

Ari: Great. I think that’s a wonderful list. Let’s talk more about keto in particular. Let’s go into some of the nuances here. Don’t worry, I won’t be antagonistic. [laughter] Maybe I’ll play devil’s advocate a bit here and there. I’m not opposed to keto being done occasionally or cyclically or anything to that effect, or even for prolonged periods of time in certain contexts. Having said that, there are a number of anecdotes, many many anecdotes, particularly of women who have done long-term keto and experienced negative effects. I’m wondering if you have any thoughts on why or if you feel they’ve done something wrong or what’s going on there?

Vanessa: It would be so hard for me to speak to that because I’d have to know what they were doing exactly [chuckles]. I’m going to say that there’s just so many misconceptions about what keto is and also what the state of ketogenesis is. There’s not just one path to Rome to get to a state of ketogenesis. You can actually get there even with a high-carb diet [chuckles]. There’s actually studies shown with enough caloric restriction you can actually get there.

What I found through working with thousands of people in the past several years is that a lot of people think they’re doing keto when they’re not. There’s even research showing there was a paper that came out I think last week showing that keto was bad for cardiac health and they were using I think 150 grams of carb a day on a self-reported 24-hour assessment.

I think the definition of keto I’ve always said it has a bad branding because it was always associated with keto acidosis that a lot of people– It almost has this negative connotation where I like to think of it as a low carb prioritized protein approach with nutrient-dense food and selective carbohydrates. That to me is such better way to look at it. It would be really hard for me to opine on what was going on in those particular situations unless I could see exactly what they were eating and what the issues that they had were.

I can’t address the fact that some of the complaints that people have are typically related to thyroid and hair issues. What I’ve seen a lot of times what’s happening there is that it’s more a result of chronic dieting and just not eating enough calories. You can do that on a lot of different diets. If someone’s eating a 1,000 calories and they’re doing protein spraying modified fast because that gets you into ketogenesis and they’re doing it every day for months and months. I could see how that could probably cause some issues. It’s really hard for me to opine without seeing what they were actually doing.

A lot of the criticisms against keto are that it negatively affects the thyroid whereas I tend to think that it more has to do with making the body more sensitive to the thyroid in the same way that the body becomes more sensitive to insulin which is one of the things that keto is so great for. If it’s done well, it really helps overcome insulin resistance and there’s a lot of evidence showing that.

I don’t believe that it’s for everyone. I do think that ancestrally our bodies are designed to go into ketogenesis very easily. Many people wake up in the morning being in a mild ketotic state. I think there’s benefits to being in it. We were designed to be able to go into it. We definitely would’ve had periods of time where you couldn’t access food. I’ll never argue that it’s the number one diet in the world or that everyone should do it. I think that you have to experiment and find what works the best for you and what you can also sustain for a long period of time.

I’m someone who loves it and I love understanding that there are benefits to ketones that are really interesting in terms of their signaling, their epigenetic effects, especially there’s potential signaling mitochondria to uncouple, I think that it’s really fascinating but, I’ll never argue that it’s the best thing for all people or all women or anyone.

Ari: Do you see the keto diet as a hormetic stressor? Since it’s for example as you said a fasting mimetic, and I think it’s pretty easy to argue that depleting or not including carbohydrates in the diet is essentially a form of metabolic stress and metabolic stress is a good word in this context, not a bad word. As you know Vanessa, my next book is on the subject of the benefits of metabolic stress. One of the characteristics that defines healthy metabolic stress is that it’s intermittent in nature and it’s not chronic. For example, exercise is profoundly enormously healthful. There’s a strong case that fasting is very helpful as well, and we could go on down the list of other types of hormetic stressors here as well. Hot and cold, for example, but when one of these becomes chronic rather than intermittent, it can become a form of harmful stress rather than helpful stress.

Now, obviously, the time durations probably differ between something like fasting versus high-intensity interval training. Interval training, we’re talking about minutes. Fasting or intermittent fasting, we might be talking about days, or weeks, or months or something like that. Do you think that the benefits of keto diets are likely to turn to harm if one does it chronically, systematically, all the time for months and months and months, and do you think that there needs to be an intermittent or cyclic nature to it?

Vanessa: It’s funny because when you first asked me the former question, my brain right away went hormesis because we just spent an hour talking about that right before this on my podcast. I was wondering if that’s how you viewed it, in terms of a hormetic stressor, so it’s really interesting. I don’t know if I could say that because we don’t have the scientific evidence yet to say which diet makes humans the healthiest and live the longest for everyone. We will just never have that information because so many of the things that we do, we won’t find out until the end of life. It’s really hard to say and answer some of those things, but I would say that it’s probably pretty rare that most people are doing keto 100% of the time because it is very restrictive for a lot of people. It’s one of the reasons that I’m more so personally, an advocate of a modified ketogenic approach with a higher protein intake. The traditional standard ketogenic diet actually does have some issues when it comes to children who were on ketogenic diets, strict ketogenic diets for epilepsy.

One of the main critiques of that approach is there were issues with growth. I think that that’s because childhood is one of the times that you need protein the most, you need more protein. There’s lots of different stages in life where we need to increase our protein consumption considerably. Like childhood, anytime you’re growing, that includes resistance training as an adult, if you’re pregnant, anytime you’re sick, and anytime you’re getting older, we need to eat more protein than average. That means most of life. [chuckles] You need to be eating more protein than average and our dietary protein recommendations are more in line with ketosis recommendations for protein for the standard ketogenic diet.

I prefer to personally promote a modified ketogenic diet, which is a higher protein approach because there’s a lot of research done actually by Eric Verdin, who was trying to find a way to make ketogenic approach more sustainable for families who have to do this kind of approach for their children because it’s very difficult. He wanted to see if while we increase the protein amounts, then can we sustain it longer, can we make it easier for the whole family, and also for the child who’s doing it? He found that ketones were not that altered especially the ketones that matter the most. That being breath acetone, which is the most associated with seizure reduction. He wrote–

Ari: This is by doing a higher protein intake?

Vanessa: Yes, a higher protein ketogenic diet. Modified ketogenic diet is how it’s typically referred to. I also I’m such a big believer in building muscle and doing resistance training that, to optimize for muscle accretion, you really have to make sure that you’re getting a little bit more protein for most people than you would on a traditional ketogenic diet. Because like myself, for example, I eat more protein than on a standard ketogenic diet, I also get bumped out of ketosis because of gluconeogenesis.

That’s just a natural part of the day and then there’s other times of the year when I’m eating more seasonally but most people that I talk to, are not doing. I only know one person actually who is a bodybuilder, a ketogenic bodybuilder that I really respect who is in ketosis like 99% of the time. I just don’t think that–

Ari: Is that Luis Villaseñor?

Vanessa: Luis might. No, I’m talking about Robert Sikes, Keto Savage.

Ari: Oh, okay.

Vanessa: I think he’s in ketosis all the time. I don’t know if Luis is all the time. I spent time with him in Spain at a conference and I don’t remember looking at what he was eating or asking him about that, but I just think it’s a very small percentage of people who are not doing it for medical reasons who are in ketosis or ketogenic state all the time. I don’t think it’s a real huge concern because I think most people are either eating more than 20 grams of carb on a regular basis or if they’re doing a modified ketogenic approach they’re eating more protein. I much prefer even a protein spraying modified fast a total fast for the purposes of maintaining muscle mass and not losing too much muscle mass. That’s my answer. [laughs]

Ari: Speaking of protein, there are some keto advocates who as you’ve alluded to basically emphasize the importance of keeping it low protein to stay in nutritional ketosis, and other people such as yourself are speaking more to the modified ketogenic diet with higher protein intake.

Vanessa: Luis being one of them.

Ari: What is your take on the differences, the pros and cons of each side there?

Vanessa: Of the side of doing the traditional keto?

Ari: Yes. Do your best steel man of the people who are arguing in favor of lowering protein intake for the sake of maintaining nutritional ketosis more strongly versus the people in your school of thought. What do you perceive as the trade-offs there?

Vanessa: I think it would have to be in the context of a certain goal for me to– Is the goal improving body composition or getting more fat loss or improving longevity or is there or just overall health optimization?

Ari: Is there one that you feel that strict nutritional ketosis would be superior for?

Vanessa: That’s a really good question. There’s only really one I would say that’s probably being in a state of medical ketosis for a therapy. It’s not just epilepsy, there’s other therapeutic reasons for doing strict ketogenic that outweighs others. I think there’s a clinic in Hungary they used to be called Paleomedicina and they do a ketogenic carnivore treatment for cancer. They’ve had over four maybe five year now glioblastoma survivor doing this approach. I don’t think it’s necessarily only epilepsy that would benefit from that, but I’m not a medical expert or a doctor or anything like that.

With regards to fat loss, I think if you’re just focusing on weight loss, you could lose more weight potentially doing keto all the time but you wouldn’t necessarily be losing just fats, it may come at the expense of some lean mass because there is a period of proteolysis that happens when you go into ketosis. I think that potentially someone might just not be eating enough protein to again trigger muscle protein synthesis by getting enough leucine because they would be afraid of gluconeogenesis.

That’s something that I try to speak about a lot because you don’t need to fear this glucogenesis boogeyman that so many people fear that eating too much protein will somehow be detrimental to improving their body composition and we really have to focus on. It’s just the fat you want to lose not necessarily the lean mass. I’m not sure that it would have– Potentially I think if someone was optimizing for longevity, I think potentially it could have some effects because of the epigenetic effects, so acting as HDAC inhibitors, and there’s other epigenetic effects that are being discovered still, and perhaps the mitochondrial uncoupling of ketones.

The role itself of ketones we’re still understanding why ketones have all these amazing effects, and especially with regards to seizure reduction, we’re still understanding some of the mechanisms there. I am way more a fan of modified higher protein approaches. For most people who are just looking for improving body composition, for optimal overall energy and wellness, I’m not saying having to do that all the time, but just in comparison to standard ketogenic diet, unless there’s a real medical reason there, I’m not sure it has any other advantages. Although I will say, initially when people are first wanting to improve metabolic flexibility, it can be helpful to do either keto or a fast, for some people, not for everyone, to help them get into more of a fat-burning mode, but for others, it has to be a more gradual approach.