Reader Mailbag: Answers to the Most Common Intermittent Fasting Questions

Welcome to the first Reader Mailbag!

I’m taking a page from the playbook of one of my favorite sportswriters, Bill Simmons, and answering a boatload of your questions today.

Questions are rolling in all the time — mostly through the free newsletter or Twitter — and I love hearing from you. Keep them coming! I’m happy to help however I can.

My hope is that this mailbag (and the ones that follow) will bring useful answers together in one place and make it easier for you to find the information you need to make the changes you want. My goal is always to make it easier for you to lose fat, gain muscle, and live healthy.

Boom. Let’s get this party rolling.

As always, these are real emails from real readers.

Questions About How to Start Intermittent Fasting

Let’s get started with some questions about what intermittent fasting is, common mistakes that people make, and how to get started properly…


I’ve been following the Paleo diet for the last 2 months and I am getting interested in trying an intermittent fasting protocol. Should I wait longer before starting a protocol? Or is it advisable to jump into one, being that it’s been a relatively short period of time with the new diet?
—Chris P.

This is a good question to start with.

As Chris said, there are different styles (or “protocols”) of intermittent fasting. So, the first step is deciding which one to do. To make it easy for you, I broke down the major types of intermittent fasting and how to do them in the beginner’s guide to intermittent fasting.

Personally, I do a daily fast where I eat all of my meals in an 8–hour window (for example, from 1pm to 9pm) and then spend the rest of the day and night fasting.

That said, it’s important to note that intermittent fasting isn’t a diet. It’s simply a schedule for eating. Or to put it another way, intermittent fasting is about when you eat, not what you eat. Of course, you’ll probably see better results if you’re eating a diet of real, unprocessed foods in addition to intermittent fasting.

This brings me to the second part of Chris’ question. If you feel comfortable with your diet (whether it’s new or old), then I see no reason to wait to start intermittent fasting.

That said, if handling your new diet and intermittent fasting at the same time is too complicated, then start by focusing on one part and then move on to the next.

I’ve said it many times, but if you want to create habits that actually stick, then you need to start as small as possible. Instead of getting inspired and trying to change every aspect of your health at the same time, make small changes one at a time and actually stick to them for the rest of your life.


Do I start counting my 16 hours of fasting after completing the meal or by the time I had my first intake of the meal? For example, if I start my final meal at 8pm and finish it by 9pm, does my fasting period start at 8pm or 9pm?
— Pradeep

Here’s the simplest way to think about it: the fast starts when you stop eating. So in the example above, the fast would start when you finish the meal at 9pm.


Have you had any experience with skipping breakfast, but still having coffee in the morning?
—Darius B.

Does 20 calories of cream in my coffee hurt?
—Bradley

Can I have tea during my fast?
—My Mom

Yes, it’s true. My wonderful, shining, radiant mother has joined the intermittent fasting nation. And from what I can tell, it’s been an easy transition for her. Mothers of the world, we look forward to having you on our team in the near future.

As for having coffee or tea during your fast — you should be just fine. As a general rule of thumb, if you drink something with less than 50 calories, then your body will remain in the fasted state. So, your coffee with a splash of milk or cream is just fine. Tea should be no problem either.

In general, I think it’s a great idea to drink while fasting. Personally, I don’t drink coffee, but I do guzzle an incredible amount of water each day. Regardless of what you pour down, make sure you stay hydrated.


Dude! I’m a big believer in Intermittent Fasting. I basically don’t use any supplements and am GETTING RIPPED OUTTA MA MIND!
—Omer F.

You sir, are insane.


Can I have a fruit or two fruits (apple and banana) between meals? For example, first meal at 1pm, fruit at 4pm, second meal at 8pm.
—Pradeep

This is a great question because it should clear up some confusion about intermittent fasting.

You can eat whatever you want during the 8–hour period. Think of it as a feeding window and a fasting window. You’re not limited to two meals or three meals or some arbitrary number of eating times. During the eating period, you can eat whenever you want.

I tend to eat two meals because it’s easier to have a lot of food at once than it is for me to snack continuously and because it provides a clear start and finish to my eating throughout the day.

Another way to think of it: you are fasting after your meals, not between them.

Questions about Exercise and Intermittent Fasting

A lot of people have questions about how to exercise and train while fasting. Here are some good questions that should push you in the right direction with your training.


I wanted to thank you both for writing such a fantastic, motivating blog and for introducing me to intermittent fasting. I am enjoying watching my weight go down by basically doing something that involves no effort — skipping breakfast! I was hoping you could elaborate more on your exercise routine. I have waded through the Leangains site and the other links you mentioned in the beginner’s guide, and while very interesting, they are WAY too complex for me at this stage.
—Paul S.

Readers like Paul are what make our community great. He read about an idea that interested him and even though some of the details were overwhelming, he didn’t let that prevent him from taking action. In other words, he started before he felt ready.

I try to make my writing as easy as possible to use, but it’s always up to you to experiment and see if it makes sense for your circumstances. Keep up the good work, Paul!

Back to the question…

Intermittent fasting works great with most strength training programs.

I believe in strength training and compound movements. I think 99% of the population could get in the best shape of their life with only eight exercises: snatch, clean and jerk, squat, bench press, deadlift, pushups, pullups, and sprints. If you did those exercises and did them well, then that’s all you would ever need.

Here’s what I’m doing right now…

I train three days per week and I pick one exercise that is my primary goal for each workout. For example, tomorrow will be squat. My only goal is to have the 5 sets of 5 reps be the best form with the best weight I can do for that day. Anything else that I do after that is just bonus time. This gives me flexibility if my schedule is tight (it often is) and leeway to add something in if I have extra energy. For example, I might add some pullups onto the end of tomorrow’s squat workout.

When it comes to training volume and intermittent fasting, you’ll want to keep a few things in mind. First, when fasting it’s very possible that you can get better results by exercising less. This can either mean less frequently or less intensity. Most people will be on a calorie deficit while intermittent fasting, so it’s usually a good idea to exercise less rather than more.

That said, some people will want to train a lot and are still looking for ways to get lean and shed some fat. If this is the case, then you need to eat a lot (and I mean a lot) during your feeding window. For a brief period, I did intermittent fasting while training on an Olympic weightlifting team and I can tell you that I had to be very committed to eating to make it work. If you don’t eat a lot then your body is going to struggle to recover from intense training.


Thanks for all the great information. I’m on day 4 of my intermittent fasting journey. The first two days were easy, but I spent the 3rd day at home and it was tougher. I’m a triathlete and do most of my training at 5:30am, and I’ve still been able to fast from 7pm to around 11am the next day. I don’t do heavy lifting so I think I’m ok fasting after a workout. What do you think?
—Bradley

When it comes to training while fasting, my primary suggestion is to keep track of how you feel and base your decisions off of that.

In my experience, I have never had trouble when doing strength training while fasting. As long as you’re getting good nutrition within the 24 hours before and after training, you probably have nothing to worry about when it comes to training fasted.

That said, if you’re going to do endurance training (like the triathlons that Bradley is training for), then I would be more careful.

The most important thing is to pay attention to your body. If you don’t feel good training on an empty stomach, then guess what? Your body is trying to tell you something. There’s no reason to be stupid about it. Try it out, pay attention to your energy, and see how your body reacts.


I workout before work at 6:30am and I’m looking to do a 16/8 fast. My last pre–training meal is at 8pm and my first meal after training is at about 1pm. Could this work or should my post–workout meal come sooner after working out?
—Neville K.

I try to eat my biggest meal of the day post–workout. Usually this meal comes within an hour or two of working out. In my experience, this is what has worked best for me.

That said, Neville’s situation is a good lesson on choosing your goals. If fat loss is the most important thing for you, then I would probably stick with the 1pm meal. The primary benefits of fasting come around 12 to 16 hours after your last meal.

If training heavy, bulking up, and gaining muscle is at the top of the list, then I would probably scrap the intermittent fasting and get a big meal right after working out. In other words, it comes down to your priorities.

If you are in Neville’s situation and your post–workout meal comes in the middle of the workday, then it can be easy to find yourself caught up in the day’s affairs and running to the nearest Subway at the last minute. It’s probably a worthwhile investment of your time to plan out your meals in advance so that you can be sure that you can refuel with high quality nutrition after your workout.

Concerns and Adjustments With Intermittent Fasting

Intermittent fasting is becoming popular, but it’s still not the “normal” thing to do. As a result, you may have some concerns about it or you may want to make some adjustments to your intermittent fasting schedule. Here are some common questions I’ve seen that should help point you in the right direction.


What if I ate my first meal at breakfast, skipped lunch, and then ate my second meal at dinner time?

This idea would work well for one reason, but not well for another reason. Let’s talk about both.

First, if your goal is to lose weight, then skipping lunch should help because it decreases the number of calories that you’re eating throughout the day. As I said in my article on lessons learned from 1 year of intermittent fasting, even if you try to eat two large meals instead of three regular meals, it’s hard to get the same number of calories. Even if you want to eat more, you often end up eating less.

So the end result of skipping lunch is that you would probably reduce your overall caloric intake and end up losing weight.

However, one of the primary benefits of intermittent fasting is that it puts you in a fat burning state. In other words, fasting makes it more likely that you’ll burn fat and not muscle.

This is where skipping lunch gets tricky. After you eat a meal, your body spends a few hours processing and digesting that food. Once you digest your food, you enter what is known as the “post–absorptive state.” You remain in this state until 8 to 12 hours after your last meal, and only then do you enter the fasted state.

In other words, you need to have at least 8 to 12 hours off from eating before your body enters the fasted, fat–burning state. This is why you want to squish your meals into a smaller time frame rather than spreading them throughout the day.

While skipping lunch would decrease the overall number of calories and probably help you lose weight in the long run, it would also spread your meals out and make it harder to get past that post–absorptive state and reach the fasted state. If you want the benefits of intermittent fasting, then you need to be fasting for at least 12 hours.


I shouldn’t have much trouble skipping breakfast during the week, but I’m worried that I can’t stick to intermittent fasting on the weekends. Is that alright?

Yes, yes, yes. This is a good lesson for any new habit or behavior change that you want to make in your life.

Just because you can’t do intermittent fasting on Saturday and Sunday, doesn’t mean that it’s not worth doing during the week. Those two days don’t eliminate the benefits you get from doing it for the other five days.

This same philosophy applies to everything from lifting weights and eating healthy to creating art and writing thank you notes. Is eating one healthy meal each week better than eating none? You bet. Is squatting once per month better than not squatting at all? Damn straight.

Just because you don’t do something as often as you like, doesn’t mean you shouldn’t do it as often as you can.


My one concern is that I will lose muscle mass (that I’ve worked really hard to gain) along with fat. Any quick recommendations for not losing too much muscle as I look to cut 15 pounds of fat? Or are my fears unwarranted?
—Ryan F.

Ryan is asking a good question here.

To put it simply: gaining weight (hopefully muscle) requires a calories surplus and losing weight (hopefully fat) requires a calorie deficit. It should be obvious that you can’t have both of those at the same time.

As a result, if you’re going to lose weight, then it’s likely that you’ll lose a little muscle along with the fat. Intermittent fasting comes in to save the day because it allows you to lose more fat and keep more muscle than you usually would.

In my experience, the key to maintaining muscle mass while dropping fat is to make sure that you eat enough high quality protein (and enough food in general). The basic rule of thumb is 1 gram of protein per pound of bodyweight. So, if you weight 150 pounds, make sure you get 150 grams of protein each day. If you want to boost that a little bit, up to 1.5 grams per pound, then that’s fine.


The biggest thing I’m struggling with when it comes to intermittent fasting is getting enough food in during the hours available. I’m working, coaching CrossFit, and trying to train, so time is precious. What has your experience been with this?
—Mark K.

I totally get it. It’s tough to get down enough food when you’re only eating two meals instead of three.

Like many of you, Mark has a packed schedule. I probably don’t need to tell you that cooking is basically impossible during the work day. In the end, I think the best answer is to plan your meals out ahead of time. It’s not a sexy answer, but having food made, prepped, and ready to eat beforehand is what allows you to eat enough when things get busy.

I would also suggest thinking about your entire eating window as an open feeding zone. Don’t box yourself into “2 meals” which can make it hard to get enough food down. During your 8–hour feeding window, you can eat whenever you want.

Related: While I haven’t done this myself, one of my friends cooks 90% of his food during one day each week. Then, he boxes it up and has all of his meals ready to go throughout the week. If you can fit a 5–hour cooking spree into your Sunday afternoon, for example, then you can be sure that you’ll have a lot of food ready during those busy weekdays.

What Questions Do You Have?

This is the first of what I hope will be many mailbags. In the future, I’ll answer not only questions about intermittent fasting, but also anything that fits our community’s central question of, “How do you live a healthy life?”

Losing fat, gaining muscle, transforming your habits, living with purpose, boosting your energy, enhancing your creativity, finding happiness, living longer — it’s all fair game.

If you have a question that you’d like me to answer, then send it in using the contact form here.

I can’t wait to hear from you and, as always, thanks for reading.

22 Comments

  1. elizabethe says:

    Hi James, thanks! very interesting!

    I do intermittent fasting (for several months now). I skip dinner, though, just works out better for me. I love skipping dinner because then you are sleeping through the potentially hungriest part of the fast. I did try skipping breakfast at first and I just couldn’t do it, I spent the whole morning looking at the clock going “2 hours left, 1 hour 30 minutes left, 1 hour left till i can eat,” it was not pleasant.

    I have breakfast at 7 and lunch whenever I get hungry (varies between 11:30 and 1) and sometimes a little chocolate or coffee with cream or something else just before 3. If I go later eating, I can always nudge breakfast back by an hour or however long the next day with no problems. How I do it is when I stop eating, I look at the clock and then I add 4 and that’s the time I plan to eat the next day. I guess I could set a reminder or alarm on my phone each day, but for *some* reason (lol) I have no problem whatsoever remembering what time my fast is over the next morning even though it changes slightly day to day!

    One thing I have learned from reading and researching this and from my own experience is that it is hard to do intermittent fasting if you are not well-nourished, esp. for some reason, if you are a woman. Paul Jaminet at Perfect Health Diet talks a lot about the importance of being well-nourished (and is a big fan of intermittent fasting). For me, I had to spend some time (like several months) making sure I was eating well before I could tolerate it. So, if people try it out and are struggling, you might want to address the “what” you eat before the “when.”

    But now, I love it. When it comes time to feed myself, I spend sometime really making sure it’s a delicious delicious meal and because I only have to do it twice, it’s that much easier.

    sorry for the long comment.

  2. Joyce says:

    I just love this website! I am doing the 8 hour diet and just love the additonal info you are giving on IF. Very helpful! I tried posting yesterday, but it didn’t “take.” Hopefully this one will go through.

    Thanks for all your information on IF.

  3. Joe says:

    Good one, James, informative.

    So, ever since I tried the Pritikin Diet 30 years ago while in college, I’ve been a self-experimenter. Over the years, have cleansed, fasted, supplemented, lifted, biked, ran, meditated, and practiced yoga.

    Yes, I know a lot about these things, but frankly the more I learn the more I learn I need to learn a lot more.

    Take fasting for instance. My intermittent fasting used to be one full 24 hour period per week, on a Monday, and a full week every year, the last week of a five-week detox cleanse. Now, the concept circles around what you described, an x hour window per day. Some questions about this…

    1. You say 50 calories is the limit during the fasting period. Are then the adherents of Dave Asprey’s Bulletproof Coffee (coconut oil + butter blended in coffee) — who subsist on this till mid afternoon — not in an intermittent fasting state?

    Whether yes or no, many on BP coffee claim substantial fat loss and high energy. I’ve tried it for some 3 mos and the results are inconclusive.

    Given my resistance training, I need to feed my wee liddle muscles. I grabbed onto Tim Ferriss’ research suggesting that ingesting 30 grams of protein within the first half hour after arising is important, and will improve satiation all day long.

    2. How problematic is it that an intermittent faster who weight trains gets no protein in him/her from 9PM till 1PM the next day?

    Particularly on training days, I try to amp up protein ingestion post workout and eat a slow absorption protein right before bed (like casein or cottage cheese) to keep feeding me during sleep.

    I could go on, but I’m compassionate.

    Thanks in advance for your views re my questions.

    -Joe

  4. Ana F. says:

    Hi, I am new to intermittent fasting. I am female, 5’1″ and weigh 97 pounds. I’m skinny fat, so I can be considered underweight, but really need to lose inches and gain some muscle. I am doing a 14 hour fast — I end my fast at 5:30pm, but I have breakfast at 7:30am because I am also doing the Slow Carb Diet, which requires me to eat within 1 hour of waking up. So I eat a heavy breakfast, a heavy lunch and a lighter early dinner. I notice that most fasting schedules promote having the first meal closer to lunch time. Could my eating schedule be a hindrance to fat loss?

    Thanks!

  5. Olivia says:

    Hi! Is it mandatory to train before your first meal? Or can my fast break before training? For example, my schedule works best with my last meal at 5pm and my first small meal (20-25% of total calories) at 9am. I would train at 12. Then finish the remainder of my calories by 5pm.

    • James Clear says:

      Hey Olivia — thanks for reading. There’s no “right” way to do your training in relation to intermittent fasting. The schedule you outlined above should work just fine.

      On my end, I usually eat my first meal around 12pm, train around 6pm, and eat my last meal around 8pm. There are plenty of good options. Do whatever works best for you.

      Good luck!

  6. Marela says:

    Hi,

    Its been 5 days since i began intermittent fastening. I am trying to loose at least 20 pounds which would be my healthy ideal weight. I have gotten used to skipping out on breakfast and its working great for me. Also i munch on low carb chocolates or snacks when i have cravings ( which is becoming less and less now) . I play compeitive womens soccer and usually play the entire 90 minutes, sprinting up and down the field. Most of my games begin at 10 am Sundays, so would you reccomend that i skip out on eating anything before the game but take amino acids with my water during the game? After, I would make a big protein shake with lots of fruits and vegies. Would this be the right way to do about this?

    Thanks
    Marela

    Thanks

  7. Cody g says:

    I could almost eat all my calories for dinner almost. I’m a big eater but not a fan of frequent eating. What’s your advice?

    • David says:

      I wish I could eat that infrequently. I can only go down to about 6-7hr eating windows. It might work even better for you, allowing for your fasting window to be larger and thus burning fat for a longer period. Just make sure you hit your macros with that dinner!

  8. sammie says:

    Hey james. Love the article, I was wondering if there is anything at all I can eat while fasting?

  9. Luke says:

    Hi, I am very interested in this intermittent fasting and thanks for your explanation. What I wanna ask is: if I workout in the middle of 8-hour window, may I still get a benefit of fat loss from fasting? (Fasting from 9pm to 1pm, my workout at 4 or 5pm, so I workout 3 to 4 hour after my 1st meal).

  10. Elionora says:

    I’ve been doing IF for 7 days now 16-18 hours of not eating and lifting 2-3 hours before I consume any food, I’m down 11 pounds could that be water weight ? Or is that actually fat ?

  11. Taya says:

    Hello there,

    I am on my 6th day doing the 16:8 fast and am really finding it easier than I thought. I have two questions… Should I be restricting my calories during the 8 hour eating window to help with fat loss? And is it still beneficial to exercise during the 8 hour feeding window if I have missed training in the last hours of my fasted state?

    Thanks heaps.

  12. James,

    First, thanks for your lucid presentation of IF (in this and your other articles)–what a breath of fresh air! I also appreciate your focus on the necessity for self-experimentation. (In fact, most of the questions here could be answered with: “try it and see”). I’ve made a lot of progress with my health and strength gains, by doing just that. Of course, that also means (as I think you’ve mentioned)that–like any experimentation–some tools/paths will be more effective than others.

    I’ve found that tracking my info is paramount to making sense of what works, when, (and, sometimes) why. For example, because I track my food (with a phone app)and lifts (old school–paper and pencil), I saw that I did my best lifting after a few days of eating beef or salmon as protein sources.

    My questions: (1) what supplements do you take, and when do you take them?(2) to get the quantity of nutrients you need, do you consume protein shakes? If so, is that a standard part of your eating, or only on an as-needed basis (for ex., if the end of your window’s approaching and you realize you’re still short of one/more macronutrients).

    Thanks again.

  13. Maria says:

    Hi! I’m a newbie to IF but I have been working out intensively for 2 years now and have improved my overall fitness through proper meal plans and exercise!my goal right now is to get cut and I have actually reached a plateau. My question is what time is best to workout for better results and more fat loss? I do a lot of interval training with weights and the elliptical. Is it better to train during the feeding period or the fast period?and if the feeding period, should I have my protein shake pre-workout in order to get through the workout or it would stop the fasting as it exceeds the 50 calories?

    Thank you!

  14. Lisa Thompson says:

    Hi James,

    Thank you very much for not only clarifying some of the concerns I had, but helping me understand IF better and in a more simple manner. I just had one question for you. Say I have breakfast which I finish eating by 7:30am and my next meal after this is dinner at 10pm which I finish by 10:30am. Would that still count as IF? Those are basically the only times during the day when I can eat.

    Thank you very much once again! :)

    • James Clear says:

      Lisa — as long as you have a consecutive 16-hour period where you are not eating, then it would count. That said, based on my experience, you would have to have careful planning and really big meals to make your schedule work. Just make sure you’re not cutting yourself short on calories.

      Good luck!

  15. April says:

    Is working out crucial to losing weight with IF, or should one lose weight by simply just doing the IF? Also, just to clarify, you can eat as much as you want if anything you want during your eating window, or do calories, carbs, etc… Need to be watched?

  16. Alicia J says:

    I have been on every diet possible and one of my friends told me about IF. She looks so amazing and said it was so easy. I have been reading up on this for awhile now. I just started on day 3, overall it’s been pretty easy. I stop eating at 6pm and do not eat again till 12pm. I am so excited to continue on this journey and to finally to get to my goal. I need to lose 50 lbs to get to my healthy weight loss. Being the mother of two little ones,it is time to get this weight off and put me first. What exercise would you suggest for me to make the fat fall off…lol? I will be celebrating my 40th birthday in June so I want to be proud and look my best ever.

  17. Gaston says:

    HI James,

    Thanks for all this info about IF, I’ve just started this week with IF and I have to say that I had no trouble whatsoever regarding hunger during the fast. My only problem is about fruit. I love eating food but in “The Renegade Diet” it really limits the consumpion of it. I’m prett lean. Weight 160 and 5’10 tall. I believe I might be like 12% body fat, workout 4 days a week at least. Do you have any hints on how to include it in my diet?

    I am currently looking to gain LEAN mass.

    Thanks.

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