Intermittent Fasting 101 with Dietitian Julia Zumpano
Intermittent Fasting 101 with Dietitian Julia Zumpano
Cassandra Holloway: Hi there. Thanks for joining us. You're listening to the Health Essentials Podcast brought to you by Cleveland Clinic. My name is Cassandra Holloway, and I'll be your host for this episode. We're broadcasting virtually as we are practicing social distancing during the coronavirus pandemic. We're joined virtually by dietitian, Julia Zumpano. Julia, thank you for taking the time out of your day to speak with us.
Julia Zumpano: Thank you for having me today.
Cassandra Holloway: In this episode, we're going to be talking about intermittent fasting. When we say fast, we're referring to an eating style opposed to fasting for religious purposes. Today we're going to be talking to Julia about the pros and cons of intermittent fasting, everything from what can you eat, when can you eat and does it really help you lose weight? Before we dive into this episode, we want to remind listeners that this is for informational purposes only and is not intended to replace your own doctor's advice. And as a reminder, before starting any new diet program, you should always speak with your doctor first.
So Julia, I want to start off by asking you how you're doing, and if you'll tell us a little bit about what you do at Cleveland Clinic and what types of patients you see.
Julia Zumpano: I'm doing great today. Thank you for asking. I am a registered dietitian with the Department of Preventative Cardiology at the Cleveland Clinic. I've primarily focused on cardiac patients, but also see patients that have risk factors for cardiovascular disease. So diabetes, high blood pressure, metabolic syndrome, obesity, renal issues, obviously weight, and then family history of cardiovascular disease are the primary patients I focus on.
Cassandra Holloway: Great. So the whole gamut, it sounds like.
Julia Zumpano: Yes.
Cassandra Holloway: I feel like when most people hear the word fast, it doesn't exactly sound super appealing to most people if you are limiting when you can eat and what exactly you can eat, but I know that there are so many people who rave about this eating style. So to start off, what is intermittent fasting? How would you explain the premise of it to someone?
Julia Zumpano: Intermittent fasting is just when you restrict your eating for a period of time. It can be done in many ways. Fasting can be done by the amount of hours you're not eating in a day, if it's by days in the week or it could also entail a caloric fast.
Cassandra Holloway: When we talk about fasting, is it absolutely no solid foods? Can you have some drinks on it? Kind of walk us through what are the general rules of intermittent fasting.
Julia Zumpano: Generally, fasting means that you should not be eating any solid food and also not consuming any beverages that have calories. Coffee is an exception and so is tea. They technically have five calories or less per serving, but no drink that actually has carbohydrate-based calories. You can drink water, black coffee and unsweetened tea. In some cases you can have a small amount of cream in your coffee, as long as it does not provide a substantial amount of calories or carbohydrates.
Cassandra Holloway: What about electrolyte drinks that if they have the zero carb, like you mentioned, are we allowed to drink like clear electrolyte drinks?
Julia Zumpano: Clear electrolyte drink should be acceptable for that case, yes. It wouldn't inhibit the fasting process.
Cassandra Holloway: Gotcha. What are some examples of intermittent fasting? I know we hear a lot about the 16:8 rule or the 5:2 rule. Can you give us a couple different types of this eating style?
Julia Zumpano: Yes. There's three main, most common types of intermittent fasting. First one being the alternate day fasting where you alternate one day of eating, one day of fasting. Second being the 5:2 method where you eat five days a week and you fast two days a week. Third being the time restricted eating, which is the most common where you restrict your eating window to eight to 10 hours and fast for 14 to 16 hours a day.
Cassandra Holloway: Then when you are actually eating, whether it's the alternate day fasting or the time restricted eating, what should you be eating? I know you probably can't go crazy and eat tons of junk food. Walk us through kind of what types of food we should be consuming when we're allowed to eat during this fast.
Julia Zumpano: The foods that I recommend are the foods that we generally recommend for health. So grains, fruits, vegetables, lean protein and healthy plant-based fats. Minimizing junk food and snack food. Focusing on whole foods and minimizing beverages that contain calories and artificial sweeteners. So, drinking mainly water. Just improving general eating habits, looking at this as a time and an opportunity to get slight and small improvements in your diet that can help support the increased benefits of intermittent fasting, or time restricted eating or whatever that method of fasting you choose to try.
Cassandra Holloway: Sure. I want to talk a little bit about the benefits of intermittent fasting. I guess, why would someone choose to try this eating style? Obviously weight loss is a big one, but why else? What are other reasons people choose to do a fasting approach to dieting?
Julia Zumpano: There have been some good preliminary studies showing that fasting can drop levels of insulin. It can decrease aging and the progression of diseases over time. It can help symptoms of metabolic syndrome. So metabolic syndrome is a multitude of factors, including high blood pressure, elevated blood triglycerides or blood glucose, elevated waist circumference, obesity, and elevated bad levels of cholesterol. There was a specific study that took patients that had metabolic syndrome and asked them to fast at least 14 hours, and then took a control group, which ate unrestrictedly. They noticed that the group that fasted at least 14 hours showed reductions in all of those risk factors. Their blood pressure came down. Their waist circumference came down. Blood sugars and triglycerides came down.
We see a lot of benefits from a fasting state, even if it's a slight form of fasting, because what happens is that our body shifts its form of metabolism. Generally our body uses glucose as our main source of energy. And what happens is when you fast, you no longer use glucose, but you tap into your body's own fat stores to burn for energy. That creates a state of ketosis, which is a similar state that we can obtain in a ketogenic diet or a very low carbohydrate diet. The state of ketosis has been shown to decrease insulin levels, decrease inflammation, and has been shown to have multiple health benefits when done properly.
Cassandra Holloway: That's really interesting about that study that you quoted. Can intermittent fasting be dangerous or not recommended for certain people?
Julia Zumpano: Certainly. We really advise against any form of fasting when it comes to patients who currently have an eating disorder or have a history of any eating disorder. These types of diets can stimulate the eating disorder, or if the eating disorder is kind of in a stagnant stage and it's in remission, it can regenerate some of those thoughts and behaviors. We certainly want to avoid that in any form of disorder eating, history of disorder eating, and also in populations, of course, that are malnourished that need extra calories, that may have diseases or glycemic control issues that would require more frequent eating habits. With any type of diet change specifically that might affect your medications or blood sugars, you always want to consult your physician before you start the diet. Make sure you get clearance and ask if there are any ways that you can adjust medication regimen to still be able to control all the current protocols that you're trying to do to control any disease states you might have.
Cassandra Holloway: What about women who are breastfeeding? Can they try intermittent fasting? What would be your advice to that group?
Julia Zumpano: Women who are breastfeeding, their need for calories is greater and it's feeding a different purpose. So typically with breastfeeding women, I do not advise towards fasting. Maybe in later stages of breastfeeding, so if you're just feeding in the morning and the evening and not being the primary source of your baby's nutrition, then you could probably play around with it towards the very tail end. When you're starting to transition off of breastfeeding, I think that's would be a safe time to maybe play around with some fasting, but certainly not during the very active breastfeeding period where you're providing your baby's main source of nutrition.
Cassandra Holloway: Makes sense. I want to talk a little bit about intermittent fasting for people who are athletes or for people who are really active. I know I tend to work out really early in the morning and I have tried intermittent fasting before, and it made me very sick, very nauseous, very just shaky because I'm so used to eating right after a workout. What's your advice for people who work out regularly who aren't used to going these long stretches with no food?
Julia Zumpano: Fasting is not for everybody. Certainly it could just be something that it's not for you. It's okay to come to that conclusion or maybe it's just not okay for you in this timeframe with maybe you have a fitness goal, like running a marathon or doing an iron man, or you're trying to meet other goals with in regards with fitness and the fasting just doesn't work with this other goal you're trying to set. And that's okay.
You can always table fasting for a later date and time, but if you still want to try it and you are doing more intense workouts, what you could do is create a fasting state, start your fasting state earlier. If the morning time is where you need to have food, try to create a fasting state, cut it out of your dinner and try to fast more after dinner, eat an earlier dinner, eat a very large lunch, very light dinner, and try to create more of that fasting block in the evening, as opposed to the morning.
Another way you can approach it is fast on the days you don't work out. So, I mean, if you're working out seven days a week, then obviously that's not going to be possible, but maybe you do take a two day break. So that's where you could create that fasting state, those two days that you do not work out.
Cassandra Holloway: That's really interesting to think about just adjusting your eating window because I know a lot of people will do like that 8:00 PM to noon and it's easier for someone to fast overnight while they're sleeping. But yeah, it sounds like you can play around a lot with your window and what works best for you and ultimately your lifestyle.
Julia Zumpano: Absolutely. You can create that window however you'd like. I mean, you can certainly start the window at 3:00 PM and certainly still eat your breakfast at the normal time that you generally do. It really has to work for you and you want to adjust it and make it feasible. Someone who expends a lot of energy throughout the day may need a different form of fasting where you do the 5:2 method. You could try that method and the two days that you're not working out could be your two fasting days where you consume, it's generally no calories or 25% of your typical intake, which would be anywhere between three to 500 calories a day. So certainly, you could play around with it.
Like I said, if you are getting some symptoms like light headed, dizziness, nausea, that may not be the right plan for you, especially if you've tried it a couple of times and those symptoms continue to redevelop. I would try fasting in a different way meaning, try at different timings, hold days, just try it in a different format where you could relieve or reduce some of those symptoms that you are getting from the fasting. A lot of times we're not getting in enough liquid, which could also be stimulating some of these symptoms. Then you mentioned the electrolytes, trying to replenish with some of those electrolyte drinks and seeing if that helps resolve some of those symptoms as well, especially after activity.
Cassandra Holloway: You mentioned some of the side effects; the headaches, the nausea, fatigue, that irritability we always hear about like the hungry, which I think is very real. Will these side effects ever go away? Does your body ever adjust to eating like this?
Julia Zumpano: I think your body does take an adjustment. And now this is personal, so everybody adjusts differently. Everybody's body adjusts differently to change in metabolic states. I think that you just have to be aware of your body and how long it takes to adjust and whether or not this is the right plan for you. Remember that there are more than one way of fasting, of creating that fasting state and creating the benefits of fasting. If one way doesn't work for you, I would say try another. Meet with a dietitian. Schedule an appointment to see a registered dietitian or talk to your doctor about ways that you want to incorporate some fasting or that ketogenic state in your body where you can gain the benefits, but not necessarily have all the symptoms you're experiencing.
Cassandra Holloway: Absolutely. I think that's great advice. You mentioned ketosis and I feel like I see a lot of people combining keto with intermittent fasting. Is there a specific reason for that? And can you combine intermittent fasting with other types of diet, just low carbs? What's your thoughts around that?
Julia Zumpano: I think that the ketogenic diet creates that state of ketosis. A lot of times the people who are following that ketogenic diet maybe want to enhance that state of ketosis or get to it quicker. That may be why you see those go hand in hand, but they're in no means hand in hand. It's separate. Fasting is a separate form of weight loss or health or reducing inflammation than the ketogenic diet. Certainly, intermittent fasting, time restricted eating can be done regardless of the type of diet that you're following. You can be following a vegan diet and do it. It does not have a specific connection to the diet.
I think a lot of people connect the ketogenic diet and the fasting is because they create the same state of ketosis. What they're doing is shifting metabolism from burning carbohydrates as your body's main source of your energy to burning fat stores, which then drops insulin and suppresses inflammation. We see a lot of benefit there and I think that's where that connection comes, but you can still reap the benefits of creating that ketosis or ketones with fasting, but it's definitely exaggerated and enhanced tremendously when you're following a ketogenic diet.
Cassandra Holloway: I'm curious, what are the actual benefits of intermittent fasting?
Julia Zumpano: The benefits are, there are many. The first benefit that's probably the most prominent is that it decreases inflammation. The inflammatory response is responsible for a lot of disease states. So, decreasing inflammation and it also helps decrease the level of free radical production. Free radicals damaged cells so we want to decrease the amount of cell damage we can do. That leads to helping reduce your risk of cancer and of course, other diseases. It also decreases your level of insulin. Insulin resistance or insulin can cause your body to store more fat specifically can be more responsible for that abdominal obesity we're seeing more of. So, it can help specifically reduce that waste circumference in abdominal obesity. It also has been shown to reduce levels of blood pressure and levels of bad cholesterol. Of course you will see the weight loss, but it also can help with reduce the signs of aging and the progression of disease. Because what happens is when we fast, we allow our body a time to regenerate ourselves and heal.
Cassandra Holloway: When you're thinking about intermittent fasting, how long term is this eating style? Is it for a couple of weeks, a couple months, a couple of years? What's the timeframe for eating like this?
Julia Zumpano: We don't have a lot of long-term studies on fasting. We have more long-term animal studies, but of course those don't equate to humans, but we know that there's benefits. What we know is that the benefits do extend long-term. This type of fasting and type of lifestyle would go along with this the same way I would recommend a diet. You want to do something sustainable, something that you can maintain long-term because what we're doing this for is health benefit. Not necessarily just for weight loss. There is certainly an immediate benefit of weight loss just like there is with any diet, but the problem is once we're off of that diet, that maintenance period is the most challenging. That's why it's really important to choose a diet plan and a form of fasting, if you choose, to try to incorporate that into your daily or weekly plan that is feasible for you to do long-term.
The most common form of fasting that I recommend to my patients is the 14-16 hour fast. That's done overnight. The reason I recommend that most often is because I think that a lot of the evening snacking that's occurring is mindless and it's habitual and it tends to lead to excess calories and excess calories that are not necessarily needed. It's just mindless eating. I think it cuts out a big chunk of mindless eating of unhealthy calories that helps feed into weight loss, but also feeds into lowering your level of blood glucose throughout the evening, drops your level of insulin, which I think then that's where we get the positive health benefits. We're losing weight. We're dropping our insulin. We're decreasing our glucose. We're decreasing our triglycerides and blood pressure.
A lot of the times what we're eating at night are salty and sweets. We're increasing insulin. Even the salty foods are carb heavy and very high in salt. We're increasing blood pressure. We're doing it overnight. We're sleeping on that level. And then, it's influencing our overall blood pressure and blood sugars. I think it's very important to look at the conceptual reason of why we're doing it and how it's positively affecting us in many ways. When you cut a cut off eating after dinner, of course, if you can try to eat dinner an hour early, great, if not, just try not to eat anything after dinner or drink anything with calories and then see what you can do. Start there and then in the morning, you can start with just eating your normal breakfast because you're probably going to be more hungrier than normal because you're not eating after dinner.
Then start with just eating your breakfast at the normal time. Then as your kind of body adjust, which our bodies adjust quicker than we think. I think it's when we make drastic changes is when we have big effects. As time goes on, start to push your breakfast an hour later and then an hour later, and until you can extend that fasting window to 14 hours at least. Research has shown that we create ketones anywhere between eight to 12 hours of in a fasting state.
When we fast 14 hours, we know we've created some form of ketones at that point. 14 hours is really kind of a key that will get us at least some benefit there. 16 hours is a little bit of an increased benefit, but at least if you can go 14, I think you'll get benefit. Even 12. If you cut off eating at 7:00 PM, it's just 7:00 AM. That's a very realistic time, or 8:00 PM to 8:00 AM. I think making it realistic for yourself. This does not have to be done every day. I almost always start my patients on three days a week of a fasting state of 14 hours to 16 hours overnight. That's generally the way that I like to begin the intermittent fasting for my patients, because I think it's the most feasible time and feasible method to incorporate it.
Cassandra Holloway: Sure. I love that idea of starting to ease into the program, starting for 12 hours first, and then kind of... If you could do that successfully, maybe 14 and then 16, and it's kind of not jumping right in and getting overwhelmed or anything like that. You're just easing into it. I like that advice.
Julia Zumpano: I also think that then you don't get those huge influx of symptoms. If you're fasting for 12 hours, most of that, I mean that, there's 24 hours in a day. You do not need to be eating more than 12 hours in a day. It's just, we weren't physiologically really made to eat all day long. This is something that's evolved as man is evolved and snack foods has evolved. I mean, it's probably been more of a state in the last 50 years that we're eating all through the day and the night. I mean, we generally had three square meals, maybe a snack and that's it. Food availability has definitely created a problem for us. I think that if you look back at how we are physiologically made to eat, I don't think we need to be eating all day. If your physiology is reacting to you not eating, it's probably because you've been in a state of eating so much, so much throughout the day that it's just reacting to that. If you slowly transition yourself into a better eating habit, then I think your symptoms will then improve.
Cassandra Holloway: Yeah. That's really interesting. The last thing I want to ask you today is just your parting advice for listeners who are listening to this episode. Maybe they're thinking about trying intermittent fasting. What are the top things that they should keep in mind before they begin?
Julia Zumpano: Top thing to keep in mind is that number one, choose a way of fasting that will work for you. Choose a method that will work for your lifestyle. You always want to set yourself up for success. Number two is try to take this opportunity to also improve your diet. Try to take out maybe one snack food or unhealthy food you know you're eating on a regular basis and try to take this opportunity to eliminate that food. And number three is to be kind to yourself. If for some reason you mess it up, just start again the next day. It's a trial and error. Nobody's perfect. We're all trying to figure out how to keep our bodies as healthy as possible, especially today, probably more than ever. So just be kind to yourself.
There's a lot of uncertainty in the world and around us. When you're just trying to filter through making yourself healthy, there's other things that influence how you eat, what, and when you eat. So family stress, lifestyle, work, whatever it might be. Just be kind to yourself and if you mess up, just start right back up again and don't give up on it. If you need more help or more guidance, seek a health professional and have them be a tool and a resource for you to only be more successful in your health goals.
Cassandra Holloway: I love it. That's great advice to end with. So thank you Julia, for taking the time and sharing some insight about this eating style. I know you've shared a lot of really great information that I've found helpful, and I know our listeners will too. So thank you again.
Julia Zumpano: Oh, thank you. Thank you for having me and stay safe.
Cassandra Holloway: To learn more about working with a registered dietitian, visit clevelandclinic.org/nutritiontherapy. If you want to listen to more Health Essentials featuring experts at Cleveland Clinic, subscribe wherever you get your podcasts from or visit clevelandclinic.org/hepodcast. Also, don't forget to follow us on Facebook, Twitter, and Instagram at Cleveland Clinic, all one word, to stay up to date on the latest health news and information. Thanks again for listening and stay safe.
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