Intermittent Fasting & Mental Health: The Science Behind What Diet Culture Isn’t Telling You

Transcript

Ellie Pike: 
If you've heard the hype about intermittent fasting, you're not alone. From social media influencers to wellness blogs, it's often pitched as a simple, almost prehistoric solution to modern health struggles. But beneath the surface of this eating trend lies a more complicated reality, especially when it comes to mental health, social connection, and our relationship with food. Here to make sense of these conflicting narratives is Registered Dietitian, Jennifer Vittitow.

Jennifer Vittitow: 
So I'm Jennifer Vittitow. I've been a Registered Dietitian for close to 20 years now, since 2006. I've been with ERC almost 10 years, and I'm currently serving as one of the Regional Directors of nutrition.

Ellie Pike: 
In today's episode, we're unpacking the science, the side effects, and the sneaky ways diet culture can hide behind the language of discipline. We'll also offer a gentler, more sustainable path forward. One built on balance, flexibility, and trust in your body. You are listening to Mental Note podcast. I'm Ellie Pike. So I wanted to start with just what is intermittent fasting?

Jennifer Vittitow: 
So intermittent fasting is a pattern of eating that includes regular intervals of fasting, just like the name implies. Just like other types of diets that we've heard throughout the years it is primarily for weight loss is how it's typically marketed. The difference though, between intermittent fasting and traditional diets is that intermittent fasting typically doesn't focus on what foods you should or shouldn't eat.

Instead, it focuses on when you should and shouldn't eat. There are a variety of different intermittent fasting plans out there. Some plans call for fasting for 12 to 16 hours per day. Others say to fast one day and then eat the next and go back and forth with that pattern. All of the intermittent fasting plans, the thing that they have in common is they limit the time a person is "allowed to eat."

Ellie Pike: 
I think that this sounds very interesting to learn more about because it is so different than other diets in some ways, right? Like you said, it's less about what you're eating and more about when you're eating. So is this a recent trend or is this not something new?

Jennifer Vittitow: 
It's been growing in popularity over the past decade or so. What's interesting though is that fasting has been around since the dawn of time. In the hunter-gatherer era, people had to fast. That was just part of their lifestyle because they didn't know when they were going to find food or when they could. And then in Ancient Greece, there was this belief that fasting would help improve cognitive abilities. So a lot of people back then practiced fasting, and then many religions have practiced fasting as a spiritual discipline to connect people to God.

So fasting has been around for forever, but what we're talking about today is different than those historical practices of fasting. What we're talking about is fasting as a way of dieting, and so that has gained extensive media attention over the past few years, and even medical doctors have been recommending it some to their patients, which in my professional opinion is a little concerning. Even on a personal level, my husband came home a couple of years ago and said, "My doctor recommended I try intermittent fasting." And I was less than pleased to hear that and had a few words to share with him about my thoughts on that. But it is definitely growing in popularity.

Ellie Pike: 
It's interesting how much it's grown in popularity, and I would really love to have you present the facts really and the studies behind intermittent fasting. So what do we know so far about the benefits versus the risks of intermittent fasting and are there any long-term studies that help inform this information?

Jennifer Vittitow: 
It's a great question. And here's where I think it gets tricky because in our diet-focused world today where weight loss, unfortunately, in my opinion is celebrated no matter the cost, the media chooses to really focus on the benefits of these diets and overlooks the potential dangers. So I think it's really important to really dig into the science. What research do we have that really tells us the facts?

And so you can go on the internet, you can do a quick search on the benefits of intermittent fasting, and several things will pop up, like potentially improved blood pressure, protection against type two diabetes, improved working memory, maybe even improved athletic performance, a reduction in tissue damage and inflammation. And then of course the Internet's going to say, "Intermittent fasting can help promote weight loss."

But if you dig a bit deeper, you'll find that there's also been some research out there that has associated intermittent fasting with some negative health consequences. One being that people who fast for more than 16 hours, maybe even 18 hours a day, have a higher risk of gallstones, which can then lead to someone needing to get their gallbladder removed. And that requires a pretty serious surgery that can then lead to difficulties with digestion for the rest of your life. So not a great outlook there.

And then there's been some evidence just this past year that was presented at the American Heart Association Conference showing that eating within an eight-hour window or less, so fasting more than 16 hours a day, can be associated with an increased risk of dying from cardiovascular disease, even a 91% increased risk of dying from cardiovascular disease when compared with eating over a more traditional 12 to 16 hour period. So we have some studies out there that say, "Yes, there could be potential benefits," and we have some studies that say, "Well, there could also be some risks too." But when I was digging into the research a bit, I found a lot of limitations to these studies. A lot of these studies that have been done on intermittent fasting have been done on animals versus humans, oftentimes mice. And then even those studies that have been done on humans, they typically have a small group of humans in the study, and then a lot of humans in the study had to drop out because they just couldn't sustain the diet. So then the evidence from those studies really makes me question how relevant they are to our society as a whole, given only a small population of people were included.

But I think the big takeaway from all of the studies so far is that none of the studies can show causation. And what I mean by that is that the studies show may be associated with potential health benefits and potential health consequences, but intermittent fasting can't be said that this is why someone's blood pressure is better. This is why someone's blood glucose levels are more stable. So there's so many other factors that could have contributed to that outcome that the science just isn't there, at least at this time to say, "Yes, there is strong evidence that intermittent fasting is good for someone's health." So that's where I think it's really wise for clinicians to take a long pause before recommending any type of diet like intermittent fasting because we just don't know the long-term outcomes. And so we just don't have that evidence yet to really say, "This is going to help."

Ellie Pike: 
Well, I think that's a really interesting piece that you just brought up. The long-term evidence is really not there because a lot of these studies have been done over a really short span of time. Is that accurate?

Jennifer Vittitow: 
That's accurate. And this is what we like, long-term health choices, whether that's the food choices you eat, whether that's managing stress, whether that's your activity levels. We know that long-term choices are what really matters versus short-term choices. And so these studies only studied folks for a few months at a time. So we don't know, can a large group of people maintain intermittent fasting for years and then we don't know even if they could do that, would there be benefits?

Ellie Pike: 
So I'm thinking through the lens of someone who's looking up, "Hey, do I want to do intermittent fasting?" And they're going to see, "Oh, here's all your benefits," and not necessarily know that these are short-term studies are only done with small amounts of people or primarily on mice. To me, that feels really confusing and it can be a really convoluted message that we're getting through the marketing of diets. So can you talk a little bit about the impact on mental health, whether that's choosing to make this decision or not, or actually trying to abide by an intermittent fasting ritual and take care of their mental health?

Jennifer Vittitow: 
Right. I'm so glad you brought that up because I think oftentimes, and it's getting better, but oftentimes mental health is excluded from people's idea of being healthy. Oftentimes the focus is on physical health, and oftentimes, unfortunately, it can be about weight loss, but our mental health goes hand in hand with our physical health. We really, in my opinion, can't have one without the other. Both are required for overall health and well-being.

And so a lot of these studies that have been done on intermittent fasting have not looked at the impact on someone's mental health. There was one study though done in 2022 that did, and what they found is anyone who engaged in intermittent fasting over the past year had a higher rate of eating disorder behaviors. Things like binging, purging, laxative use, compulsive exercise, restricting, compared to the control group who followed a traditional eating plan.

And I think that one of the things that's most concerning to me about intermittent fasting is that it can take over your life. It can disrupt your day-to-day life. It can prohibit you from doing things you enjoy because if you have this narrow window of time that you're allowed to eat, you may not be able to go meet up with friends who are going to dinner. You may not be able to go to that party and enjoy the celebration. So it can really not only narrow your window of eating, but narrow your life experiences, which to me, that's concerning.

Ellie Pike: 
I appreciate that you bring up the social impact of it because I know I have seen, and I'm sure a lot of our listeners have seen that impact of somebody on a diet or specifically with intermittent fasting. I know that I've seen folks show up to a gathering late because they knew that they weren't going to eat until afternoon per se, so why come earlier if everyone else is eating brunch? And so they're missing out. But also I can tell that there's an impact of it, right?

I've noticed folks having a little bit more brain fog or not necessarily thinking clearly because they're not fueling their body that morning. And so I can tell, but they may not see it as clearly as the rest of us might see it.So I appreciate you just bringing in the full circle, the physical, the mental and the social.

Jennifer Vittitow: 
They all go together for overall health and wellbeing.

Ellie Pike: 
It sounds like there's a lot of consequences of intermittent fasting, and they're maybe not that different than other diets, especially the fact that they create this rigidity around lifestyle. So can you speak a little bit more to that and maybe diets more in general?

Jennifer Vittitow: 
Like you mentioned, diets like intermittent fasting and others lead to hunger. Sometimes that phrase "hangry" can be a real thing. Headaches oftentimes occur, fatigue, dizziness, nausea, difficulty thinking like you mentioned that brain fog, irritability, and then other mood disturbances. So these diets place so many restrictions on your life and really lead to not living your best life, not feeling your best.

And these restrictions can lead some people to develop disordered eating patterns and then sometimes even a full eating disorder because some people are genetically predisposed to developing an eating disorder. And a diet is one of those things that really can launch someone not unaware into an eating disorder. So it can be a very slippery slope. And oftentimes when we develop some behaviors, like we develop some rules about eating, they can sometimes take on a life of their own. And then more and more rules are created that we have to follow, and then that can lead to body dissatisfaction, even other behaviors like compulsive exercise.

It just becomes this mindset of, "It's never good enough, I'm not doing enough." And then that leads to low self-esteem and then somebody can feel like there's something inherently wrong with them, that they're flawed when really it's the system, the dieting system, if you will, that's wrong. And it's just feeding us, pun intended, a lot of lies.

Ellie Pike: 
I want to bring this back to what you said that there was an actual study in 2022 that showed us that this is not just a conjecture, that we actually know that folks had higher rates of eating disorder behaviors or compulsive exercise or binging. This isn't just like, "Oh yeah, I'm one in 1000." It's actually truth, so we know that there's a high risk. And I'm intrigued by the mindset that somebody might have where they feel like, "Oh, I've failed." Versus what you're saying is actually it's the diet that's failed you, and it's the message that society given you that's failing you. So I'm curious, what is the message that you wish folks could hear?

Jennifer Vittitow: 
I wish that folks could hear... I wish it was just broadcasted across every media outlet there is that diets don't work. They come with all of these beautiful, attractive promises that not only will you lose weight, but your life's going to be so much better. If you're lonely, this diet's going to help you lose weight and cure your loneliness. If you're sad, this diet's going to help you lose weight and you'll be happy. You'll have the life that you want. But it's that kind of reality that if it sounds too good to be true, it probably is. So that is true 99% of the time, if not more, when it comes to these fad diets.

I've worked with patients now in the eating disorder field for over 15 years, and so often, not always, but often it starts with them trying to be healthy. It's a genuine attempt for them to be healthy. They choose one of these diets or they pick up on one of these messages in the media and they try it, and then their brain just goes down this really unhealthy pathway and it becomes this very obsessive, rigid thing or sometimes feeling out of control and binging and then restricting and potentially engaging in other behaviors.

And it's really the diet that led to that because if they would've continued just eating their normal pattern, their brain wouldn't have gone in that direction. So what I wish people would know is that there's always going to be something flashy, if you will, out in the media. The media is intended to try to promote buzzwords to catch people's attention, and really nutrition just doesn't work that way. I wish there was something flashy we could share that worked for a large group of people, but it really, nutrition is about the basics, and if people can follow the basics, they will likely be healthy as much as within their control.

Ellie Pike: 
So I want to dive a little bit more into diet industry and also how our body responds to dieting and starvation. Before doing that though, I think you touched on a really important point of what are the basics, because I think that we've all gotten pretty confused by all the messages. And so for you as this experienced dietitian, what are the top simple basics that would really serve all of us better if we followed?

Jennifer Vittitow: 
So there's five general nutrition principles in my opinion, that anybody can follow and that anyone can receive benefits from. And it's a bit nuanced, like how you apply these five principles will look different from person to person, which is why it can be helpful to work with a registered dietitian who takes a non-diet approach and who's familiar with disordered eating and eating disorders.

But these five principles are balance, moderation, variety, flexibility and enjoyment. I'll break those down for you. It can be like, "Well, what do you mean by balance?" So what I mean by balance is that our bodies are designed to thrive off of a blend of carbohydrates, proteins, and fats. Oftentimes, diets will remove one of them, like I grew up in the late '80s, early '90s in the snack world generation sometimes as it's called, where fat was bad. But then in the 2000s, carbohydrates turned bad.

But really what nutritional science tells us is that our body needs carbohydrates, proteins, and fats to function at their best. So we need a balance of what's called those three macronutrients because those are the only nutrients we can get energy from. And of those three nutrients, I think people often are surprised to know that we need more carbohydrates than proteins or fats. And really protein is, of the three, the one we need the least of, but we still need to eat them at meals together ideally for that balance.

And then what I mean by the second principle of moderation is that we want to help someone find what moderate amounts look like for them at their age, their lifestyle et cetera. Because eating too much or too little can come with potential health detriments. So we want to help a person find what enough looks like for them, and that can vary through your different seasons of life.

Oftentimes with the patients that I work with, if it's an adolescent, they'll say, "Well, my mom" or "My dad doesn't eat as much as I have to," which may or may not be true, perception's reality sometimes. And there could be truth to it because maybe mom or dad don't need as many nutrients, their metabolism isn't as high as their kiddo. So different seasons of life lead to differences in what moderation looks like. So we want to help each person figure out what that looks like for them.

And then that third principle of variety means eating a wide variety of different carbohydrates, wide variety of different proteins and fats. So it's okay to eat refined white bread. It's okay to eat whole wheat bread. Our bodies know how to digest both of those. And eating a wide variety of different protein sources makes sure that we get all of the different amino acids that our body needs to thrive. And then eating a variety of different dietary fats also promotes overall health and wellbeing, and it makes sure that our bodies get all the different vitamins and minerals we need as well, because if we eat the same breakfast, the same lunch, same dinner, typically day, after day, after day, we may miss some of those vitamins and minerals our body needs. So that's where sometimes it's said when it comes to fruits and vegetables, eating the rainbow, eating different colors can be really helpful to get those different vitamins and minerals.

And then the fourth principle of flexibility, it's one of my favorites and one that I talk often with my patients about because it can be tough because the diet industry says, "Follow these rules, stick to this outline." But really life works when we practice flexibility and it leads to so much less stress when we just practice that flexibility that's needed.

For example, giving yourself permission to eat whatever food, meaning all foods can fit. The only exceptions would be if you have an allergy, if you have an intolerance, or if you just have never ever liked it. I'll give you an example. One of the foods I've never ever liked is fish. And I know all the health benefits of fish. Nothing wrong with fish, a lot of people love it, but I just have this mental block with fish, so I'm never, ever going to eat it, and I can live my life just fine without that.

But when we develop this long list of foods that we can never, ever eat, life becomes really tough. It gets really hard to go to restaurants. It gets really hard to go to parties and feel safe, feel at peace. So giving yourself permission to eat a wide variety of foods can be very freeing and can be very helpful because when we take those labels off of food being good, or bad, or even healthy versus unhealthy, we take away the power that some of these foods have.

So for example, if someone says, "Oh, I can never eat a brownie." Well, then sometimes our brains get really fixated on that and we kind of want to do that thing we shouldn't do that our brain's telling us we shouldn't. And then that brownie takes on so much power that sometimes our brains can get fixated on that food that we've deemed bad or not allowable, and then we can wind up actually overeating on that food, compulsively eating that food when we give ourselves permission. So it just really doesn't do us any favors to create these rigid rules. Just allow all foods to fit, all foods are permissible, and it can really allow for that freedom. And then going back to that moderation principle as well.

And then lastly, this is actually, even though I love flexibility, my favorite principle with food is enjoyment because I think food's meant to be fun. We eat multiple times a day, hopefully three meals and probably some snacks, though everybody's different, everybody's nutritional needs are different. But I'm so thankful that food tastes good. We have a wide variety of foods in our culture today that tastes good because can you imagine we have to eat. We cannot live if we don't eat. And if food tasted horrible, most of our foods tasted horrible, it would be really hard to survive.

So we have all of these wonderful foods that can be fun, that can be enjoyed, and that can allow us to connect with others. We can celebrate with food. It's not the only way to celebrate, but it's one of the ways. And I think when we allow ourselves to enjoy food that can really add to overall wellbeing.

Ellie Pike: 
Jennifer, I really appreciate how you just broke this down into five. So I'm actually going to say them again just for myself. So balance, moderation, variety, flexibility, and then enjoyment. And so I love how simple that feels. It can feel a little scary for anyone who's bought into these messages about we shouldn't enjoy or we shouldn't eat certain foods. It's an unlearning process for a lot of us.

But now I'm taking this back to intermittent fasting and I'm thinking of the individual that's like, "Yeah, I do all these things, but only between noon and eight PM." Where it's like, "Actually I do all these things except for this many hours a day." So that leads me to my next question around what our body is experiencing when we don't give it fuel for a large amount of time, like an intermittent fasting, and what does that do to our body?

Jennifer Vittitow: 
It's a great question. And to that person that you just described in that example, I would really get curious about does that really equal flexibility? The thing is is that working for you? Because that's what we want, we want the way that you eat to work for you and to hopefully be enjoyable. And oftentimes diets just don't work. We've talked about they may work for a short period of time, but it's the long period of time that we're looking for. We're looking for, can you sustain this as an overall lifestyle no matter what life may bring you? Maybe you change jobs and your schedule changes. Can your food choices change with that?

Because one of the worst things that we can do is do one fad diet after the next, because that comes with consequences. That comes with what we call weight cycling, meaning somebody's weight can go down when they follow a diet, then it goes back up when they stop the diet. And that pattern, if repeated over and over, can lead to some cardiac impacts. It can do some damage to your heart.

And then two, what diets also can create is this form of starvation, because internally our bodies don't know if we're choosing on our own to restrict or if that is what life is requiring. Like back in the hunter-gatherer era, sometimes going without foods for extended period of time was just a necessity. They didn't have our lovely conveniences of refrigerators, local grocery stores, microwaves, things like that. We do though. And so our bodies don't know if it's a choice or if it's a requirement. And so our bodies are designed to keep us alive.

And so when our bodies recognize there's been a change that less food is coming in, the body goes into action to help protect the person. And the way it goes into action is that it lowers the metabolism. It kind of goes into a semi hibernation to protect you. So then this goal of wanting to lose weight actually becomes harder. And then there's this belief that, "Okay, well then I've got to cut out more." And then that's where that slippery slope into a disordered eating pattern or maybe even a full eating disorder can occur.

So our bodies thrive on rhythm, on patterns. So it's just kind of like a child, a child needs to know that it has people around it that they can trust and that there's going to be consistency, and then that leads to safety. Same thing with our body. When our body realizes, "Okay, I'm being fed consistently," it can maintain a healthy metabolism, it can work appropriately, and everything that is within your control in regards to health will be healthy.

Ellie Pike: 
I like how you're describing it as our body can learn to trust us when we're consistent with it. And someone once described it to me as fueling a fire and your fire is just going to keep going. Whether that's your metabolism, I guess that would be your metabolism, right? And if you keep putting logs on the fire, it's going to continue to fuel that fire and just keep it going. And so I really like how you described this, and I think that you have provided so much insight today.

So I'm thinking about our listeners on the show who can really identify with what you've talked about and really experience that feeling of failure. And I'm going to say experience that feeling of failure, I don't want to call anyone a failure because I don't think that it is anyone's own choice to fail at any of these "diets."

For any of those folks, I imagine some of them might have developed the warning signs of an eating disorder, and I thought it might be really helpful if you could just outline a little bit of that of maybe this has actually turned into something a little bit more where you might want to seek help in working with a dietician or a therapist or even treatment at some point. So what are some of those warning signs?

Jennifer Vittitow: 
That's a great question, and I just want to emphasize what you said about failure. It's not the person who failed. It's the diet that failed them. And that is the power of our diet culture, because if it can make a person believe that they've failed, then they're going to keep going back to it to find the next solution. But that's not the answer.

The answer is actually to step outside of that diet culture and follow those basic principles of nutrition that we talked about, balance, variety, moderation, flexibility and enjoyment, because you can't fail at those. Those are just things that we practice day after day, and some days we really are rocking along, and then other days it just might be different. There's days where I may go without eating many fruits or vegetables, and that's okay. I was practicing flexibility, I was practicing enjoyment, but then the next day, I can try again and start over.

So there's no way to fail at that. And what we know is that when people have this sense of failure, it leads to shame and guilt, which are very powerful emotions that can lead to negative health consequences and can potentially promote disordered eating or an eating disorder. But those behaviors can be subtle to where we don't recognize that they're occurring or we don't see the direction we're headed in because eating disorders are very sly that way. Eating disorders by nature are very deceptive.

And it's not until we kind of are in that pit, so to speak, that we go, "Oh, I think I've got a problem. I think I need help." And so that's where if you have people that you love and trust that are in your inner circle and they're voicing concerns or they're pointing out, "Hey, I noticed this is different about you," it can be really humbling to hear that and try to receive that. And it can be also very powerful because if they truly care about you, they're probably saying it out of love.

So really allowing yourself to listen to what other people are saying doesn't mean you always agree with it, but just being willing to listen and go, "Huh, I wonder if there's any truth to that," can be very, very health giving, very safe and protect you from potentially going down a path towards more disordered eating or an eating disorder. If you do find that there are certain behaviors going on in your life, like food being either all good or all bad, where you have to follow these rules, and those rules really dictate your life and keep you from doing things that you used to enjoy. That could be a red flag and a sign that, "Hey, maybe it would be helpful to reach out and see who can help and what you could do," so that those rules don't become even more extensive.

If your brain is constantly focused on food or things like calories or when you're going to eat next, that can be a sign, "Hey, help may be needed here." If you feel out of control, there's this cycle of binging, then restricting or other, what we call compensatory behaviors after eating due to feeling shame and guilt, whether that's intentionally purging or using laxatives or compulsively exercising, feeling like you need to earn your food or you've got to burn it off. Those are signs that your food behaviors are taking on a life of its own.

And unfortunately, these behaviors just don't get better on their own. We can't wish them away. I wish we could. It would make things so much easier, but they just tend to get stronger and more severe and more debilitating if someone doesn't reach out for help. So it's really, I think, vital. The sooner, the better that you notice these things, the quicker you're going to be able to get these behaviors turned around and the quicker you're going to be able to get back on a healthy path.

And what I can say now, working with ERC for almost 10 years, is that freedom from these behaviors is absolutely possible. We see the most severe types of eating disorders come through our doors, and we've also seen those same people with the most severe eating disorders leave us, eventually healthy again. And when I say healthy, I mean both physically, mentally, emotionally, they're on their way. It doesn't mean they're fully healed. Recovery from an eating disorder takes years, but they've laid a very firm foundation.

So I say that to give people out there hope, that if they find themselves in this kind of pit, they're like, "Oh, these food behaviors have taken over my life." There is freedom. And it does take work, it does take effort, it will take time, but I can promise you that it's completely worth all of the time and effort it takes to get there.

Ellie Pike: 
Thank you so much, Jennifer. And we'll certainly link to Eating Recovery Center's website in our show notes. If anybody wants to schedule a free assessment, then they can just come curious and have someone else work with them to see, do you need treatment? Is this helpful? Do you need an outpatient provider? Maybe we could provide you that as well. So thank you for your words of hope and your expertise. It's been so lovely to talk with you.

Jennifer Vittitow: 
Thanks. Thanks for having me.

Ellie Pike: 
Intermittent fasting might promise control, clarity, or even a kind of wellness shortcut. But for many, the cost is steep, strained mental health, disordered eating patterns, and a disconnect from the joys of food and community. The good news, there's a way to care for your body that isn't about rules or rigidity.

It's about balance, variety, and giving yourself permission to eat with flexibility and pleasure. If you're struggling or hearing concerns from people you trust, don't wait. Help is out there and healing is possible.

If you like our show, sign up for our e-newsletter and learn more about the people we interview at mentalnotepodcast.com. We'd also love it if you left us a review on iTunes. It helps others find our podcast. Mental Note is produced and hosted by me, Ellie Pike, edited by Cary Daniels, and directed by Sam Pike. Till next time.

Presented by

Ellie Pike, MA, LPC

Ellie Pike is the director of alumni, family and community outreach at ERC & Pathlight Behavioral Health Centers. Over the years, she creatively combined her passions for clinical work with…

Presented by

Jennifer Vittitow, RD, LD, CEDS-C

Jennifer Vittitow received her degree in nutrition from the University of Texas at Austin in 2005 and completed a dietetic internship in North Carolina in 2006. She then went into private practice as…