There are many different types of fasting… intermittent, alternate day, one meal a day, crescendo fasting, extended fasts, and more! How do you know where to start? Which type is best for you?
Not every method fits into every lifestyle, I will help you determine where to start, and whether or not it might be time to switch things up and try something new.
Whether you are a new intermittent faster, you have many health issues and are looking to reverse disease, you have been fasting a while but are in a stall or not seeing progress, or are looking to prevent disease and extend longevity, I will review the many different types of fasting, so you can decide where to start and which is appropriate for you.
Sometimes when we talk about fasting we automatically think of intermittent fasting (IF) and it being the only type that we can try. IF is likely the most popular type and what most people start with, but there are many additional fasting protocols that might work for you.
If you haven't heard of them or maybe you're in a rut or stuck and you just need to change up your routine and try something different, there are other fasting methods that you can try. There are some methods of fasting that tend to work well or better for certain people, those who have certain diseases, or just starting out.
Let's go through several of the many types of fasting.
Let's start with crescendo fasting. With crescendo fasting, think of it as kind of like a wave, something that waves in and waves out. Crescendo fasting is basically the beginning stage of intermittent fasting. What I mean by this is you're going to basically get your feet wet, dipping your toes into fasting if you haven't done so already. Or, if you are someone who has a lot of different health issues or you have known adrenal or thyroid issues or many autoimmune issues, or you have several different autoimmune diseases that are diagnosed and your health is really not in a place where you want to shock or stress your body, crescendo fasting is a great option.
Crescendo fasting is easing yourself into about 16-18 hours of fasting. Maybe even starting at 14 hours of fasting and not doing that on any two consecutive days. Start with every other day, maybe three days a week, four days a week at the most, or maybe even just starting with two days a week of 16 to 18 hours of fasting. What this does is prepare your body for extended periods of time without food. Then assess... take a step back and view, is fasting making me feel better or worse? What is the progress that I'm making?
Taking multiple medications or being diagnosed with several autoimmune diseases can make fasting a little tricky, especially if you're taking meds that make you sick or need to eat. Starting out with 14-18 hours of intermittent fasting a few times a week can determine whether or not it's suitable for you. You could start with Monday, Wednesday and Friday where you will stop eating dinner by 6 or 7 p.m. and then not eat the next day until at least 10:00 in the morning. See how you feel during that time. Are you noticing any new or worsening symptoms?If you feel better or make even a small amount of progress in that time, such as you feel a little bit more energetic or you slept better that night, I would keep going with it and work your way up.
Again, crescendo fasting is where you're not fasting two days in a row. You're only doing it every other day or even every third day, just to feel it out and see how your body responds to it. This is for people who are on a lot of medications or have multiple health issues.
The second type of fasting is intermittent fasting, which is when you only eat during certain times of the day. You can think of it as time-restricted feeding or time-restricted eating.
Some people like to think of it as eating with time restrictions. This is because it often sits better with people than the term "fasting." When I mention fasting to some people, they get freaked out or they think they have to go days without eating.
Intermittent fasting means that you eat during a specific time window on most days.
I always encourage people to have at least one feast day every week or every two weeks, whether you're doing intermittent fasting or not. This helps keep your body guessing, which is important so it doesn't get used to one routine.
There are two popular types of intermittent fasting: 16 to 8 and 18 to 6. With 16 to 8, you fast for 16 hours and then eat during an 8-hour window. With 18 to 6, you fast for 18 hours and eat during a 6-hour window. There are many different variations of intermittent fasting. You might fast for 20 hours, and then eat for only four hours. If you are an intermittent faster and want to see the most health benefits, it's important to switch things up. If you eat the same foods at the same time every day, you will probably stop seeing progress at some point.
If you want to mix it up, you can try changing when you eat. Eat at 10am one day a week, and noon the next three or four days. Then eat at 5pm one day a week, and 3pm the next two days. That keeps your body guessing and it won't expect food at the same time every day. I usually eat around noon or 1 pm, but I do not always eat at that time. Sometimes I skip a meal or have an extended fast. If I know I am going to do a one-meal-a-day (OMAD) fast, I will usually eat earlier on that day.
A little word on snacking during your eating window... I would encourage you to stop snacking as quickly as possible because snacking can stimulate insulin production in between meals, which you don't want.
Many health authorities have been telling us for a long time that we should eat often and snack to "keep our metabolism up". But this actually makes our insulin levels high. And remember, when insulin is high, that means we're not burning fat - we're storing it. You will not be able to use the fat for energy when insulin levels are high. That is why intermittent fasting is important- it helps to lower your insulin levels so that you can use the fat for energy.
If you want to try intermittent fasting or time-restricted feeding, it is possible for most people. If you are taking prescription medications or have a lot of chronic illnesses, it is best to talk to your doctor first. They might be willing to monitor you during the first few weeks that you are trying this out. You can also get some labs drawn before you start this lifestyle and then check them every three to six months. This will help you see how well you are doing. Almost anyone can try intermittent fasting and time-restricted feeding. I have tons of resources inside my programs to help you know which labs to request and how often to have them done.
You should not do intermittent fasting if you are pregnant, breastfeeding, or have a history of eating disorders. Children should not fast either. Almost anyone can try intermittent fasting, but if you are worried or have any questions, talk to your doctor. They might be able to help you figure out if intermittent fasting is right for you and what kind of monitoring you will need.
The next type of fasting I'll talk about is OMAD or one meal a day. This is still a type of intermittent fasting because you're still eating most days. OMAD restricts your feeding window to 1 to 2 hours, meaning you only eat either lunch or dinner during that time. Some people like to eat breakfast and then not eat again until the next day. But most people eat either do lunch to lunch or dinner to dinner. I usually do OMAD about once a week, but that's it. Here's why...
You can lose weight by eating one meal a day for a couple of weeks or months. But this usually doesn't work for long-term weight loss because your body gets used to the routine and you may stop losing weight.
Sometimes OMAD backfires on people because if you eat the same amount of food every day, your body may get used to it quickly. It can be hard for women to eat enough in just one meal, and they may create too much of a caloric deficit. If you're only eating around 1000 calories in your one meal, your body may adjust down its metabolic rate over time. This means that your body will start to wait for food at the same time every day, and hang on to what you are eating because it perceives you not eating enough and may down-regulate metabolic systems.
Remember, with fasting, we are trying to mimic the periods when our ancestors had food and the periods when they didn't. So if you do the same thing every day, your body will get used to it over time. Your metabolic rate may start to adjust to the amount of calories you are eating. This may be 1000-1200 less than what you are eating now. So be careful with one meal a day fasting. I would suggest eating the lunch meal sometimes and the dinner meal sometimes, or just eating it a few times a week.
And then the other days you're eating two meals or you're doing a little bit longer of an extended fast so that your body is kept guessing. Many people like the idea of eating only one meal per day. There are many books and podcasts on this topic. However, in most cases, people only use this method for a couple of months because they stall out. So, the key is to change it up. OMAD can work really well for weight maintenance. If you have reached the weight that you want or if your health has improved, this usually works well. But it doesn't work the best for weight loss. The reason is that it can alter your metabolism rate, which is not what you want when you are trying to lose weight.
I suggest you try including OMAD maybe 1-2 times a week, but don't do the same thing every day. Additionally, alternate the times you eat your meals from day to day.
The next type of fasting I want to talk about is alternate-day fasting or ADF. This is just what it sounds like: you fast every other day. You are alternating your fast days with your feast days. This works well for people who have seen weight stalls. I've used this technique with my clients many times. If you're not seeing the results you want from either intermittent fasting or from the OMAD diet, then maybe you need to try something different. Alternate day fasting is good for weight stalls because you're doing something different every single day. So one day you're eating, the next you're fasting, then the next you're eating again, and then the next you're fasting again.
ADF is a great way to help your body lose weight. This is because you are always making your body adapt to something different, which keeps it guessing. The key is not to restrict your calories on the eating days, but to eat normally. If you are doing alternate day fasting, make sure you eat at least 2 meals on your eating day. It is very important that your body thinks it is well-nourished and not starving. If your body thinks it is starving, it will start to decrease your metabolic rate.
If you're not getting enough calories, you can add some fat to your food. You could add butter or oil to your vegetables or meats. That will help you get the calories you need. I will say most people don't have a problem getting enough calories! If you find that you get full quickly, you can add a little bit of fat to make sure you're getting enough.
Alternate day fasting is a way for people to fast every other day. This is a good way for people who have done intermittent fasting and have found that they do well with it. Their body is used to this type of fasting. Alternate day fasting can help you lose weight if you have seen your weight or progress stall. It can also help with reversing insulin resistance. If you have a lot of weight to lose, this might work better for you because your body will have more time to burn fat.
The next type of fasting is called a 5-2 or a 4-3.
This type of fasting was developed by Michael Mosley. On two days a week, you eat 500 calories or less. Another option is to do a full-out fast on those days. The idea is to eat around 500 calories or nothing at all 2 days a week, so that your body is only calorie restricted every once in a while. Remember that if you restrict your calories for a long time, day after day, you will get in trouble. If you join a weight loss program and are supposed to count your calories and keep them under 1200 per day, you can really mess up your metabolic rate. This happens when you do this for many months, not just occasionally.
Changing up your routine can help you break through a plateau. This is because it can be unexpected and your body won't be used to the same thing every day. Some people only eat 500 calories on Mondays and Tuesdays. They eat their normal diet the rest of the week. In my experience with clients doing a 5-2, it tends to work better if you do the two days in a row because you will be continually depleting your glycogen stores, which helps you to tap into fat burning.
The 5-2 or 4-3 methods tend to work really well for people who might see a stall or they're just looking to change up their fasting regimen. Remember, it's important to throw some feast days in there. I said "feast day" and not "cheat day." This means that you should have a day where you can eat all types of healthy foods. I don't encourage you to have a cheat day where you gorge yourself on unhealthy foods.
Feast days are important. You can implement them every couple of weeks, or at least once a month. These are important because they let your body know that you are getting ample nutrition, and it does not need to lower your metabolic rate. Sometimes, if you have been too restrictive with your diet or if you have been fasting too much, it can be helpful to add in some feast days. This will help your body relax and not feel so stressed.
The last type of fasting I want to talk about is extended fasting. Extended fasts are when you don't eat for a longer period of time. Extended fast can be very helpful as well for just about anyone.
I consider anything over 42-48 hours or more to be an extended fast. By doing an extended fast, you can help to reverse insulin resistance and all the diseases that are associated with it, like heart disease, type two diabetes, prediabetes, PCOS, and many others.
If you have one of the diseases I mentioned, or prediabetes, or elevated blood sugar, doing long fasts for 36-42 hours 2-3 times a week can help to reverse insulin resistance more quickly than if you just did intermittent fasting most days. This is the THERAPEUTIC LEVEL of fasting. It can be a little bit scary to think of not eating for 36 to 42 hours, especially if you have never tried intermittent fasting before. But you can work your way up. Once you get past a 24 hour fast and the first sleep, it isn't so scary!
I'm at the weight maintenance phase where I'm not looking to lose any more weight. I also don't have any major chronic illnesses that I'm trying to reverse. So I like to do an extended fast for my health and longevity, and to switch things up so my body doesn't get used to doing the same thing every day. I only do an extended fast about every quarter (every 3 months).
If you are reversing a disease, I would recommend the therapeutic level of fasting (36-42 hours) 2-3 times per week as a goal until the disease process is reversed.
If you’re feeling curious and want to give intermittent fasting a try, don’t miss your FREE guides. It's a great way to get started safely with an intermittent fasting approach that works for your lifestyle. Fasting can be a great way to jumpstart your weight loss journey or simply reboot your metabolism – but it’s important to understand which type of fasting is right for you.
I encourage you to listen to the companion podcast episode for this blog post. Click HERE to listen now!
Pass this blog post along if you know somebody who's interested in learning about what type of fasting is best.