It has been a little over 3 years since I started the practice of Intermittent Fasting. On the list of positive steps I’ve taken to improve my health, only removing wheat has yielded greater benefits. As great as things have been, I have made a few mistakes. Let me share my errors, so you don’t need to repeat them.
#1 Fasting While Sick With a Cold
Don’t do it. In 2009, I decided to see if fasting would have any impact on my health when I got a cold. From the post Intermittent Fasting – The Common Cold:
Doing an Intermittent Fast while I had a cold did not work for me. I am a huge proponent of IF, but I do not think it is wise to do if you have the common cold. I started thinking about this from an evolutionary perspective and it made sense. If a member of the tribe was sick, they wouldn’t be invited on the hunt (or gather). Instead, they would be treated back to health so they could participate in future food gathering for the benefit of the group.
My current belief is if you catch a cold, you should rest and load up on foods that support strong immunity such as bone broths. Fasting does put a stress on the body and probably should be avoided when the body is dealing with the stress of fighting off the common cold.
#2 Excessive Fasting While Weight Training
This may just apply to ectomorphs, but I what I discovered in 2009 was that fasted weight training not only resulted in fat loss, but without a post-workout meal I started to lose strength.
From a paleo perspective this makes sense. I was hungry and went on a hunt. At the hunt I engaged in a battle. For me that was lifting weights at the gym. A successful hunt would have resulted in a kill and a meal. After a few months, I kept returning from the hunt in a hungry state. From the standpoint of nature, I was being every bit as energy foolish as the cardio junkies. That behavior gets punished if it happens repeatedly.
#3 Not Eating Enough After the Fast is Over
When I did 70 days of 16 hour fasts, I began to have issues in the second month. I detail my experience in the post Intermittent Fasting – 70 Day Review of the Leangains Method. I was getting tired, my body felt cold and my immune system was weaker. I got a few comments stating that I probably wasn’t eating enough. At the time I felt I was eating enough and that I could make the protocol more effective by adding more randomness and taking periodic breaks. Now I am thinking the truth is somewhere in between.
The more I read about metabolism, the more it makes sense that extended periods of fasting would result in a slower metabolism and reduced body temperature. Appetite is reduced. Nature is energy efficient. For a daily protocol to work, I would need to force myself to eat more until the sluggishness goes away and body temperature increases. If that isn’t enough then a break is necessary.
So the take away lesson I learned is to increase calories after your fast if you feel your metabolism slowing down. Override your reduced appetite. Failing that, take a few days or a week off from any fasting until you are back to baseline.
#4 Eating Too Much After the Fast Ends
This is common when you first start fasting. It happened with me in the first month or so and it happens with others. The good news is it tends to be self correcting. As you gain comfort with the practice of Intermittent Fasting, your post-fast meals will stop be gorge fests.
How about you? Do you have any lessons you’ve learned with Intermittent Fasting? Please share them in the comments.
Oct 24, 2011 — 9:40 am
i am very new to fasting. the few fasts i have done have gone from about 10 the previous night to 6 pm the next, so about 20 hours. i am really surprised i am not hungrier in my re feed. I eat a huge meal to break it but am not too hungry throughout the rest of the night. i will say, it’s not as hard as i thought it would be. i save money and time not having to worry about lunch although i don’t think i would do it more than once a week.
Oct 24, 2011 — 9:50 am
@Chuck – I did find the problem outlined in #3 only happened when I was doing the daily 16 hour fasts. When I did the EatStopEat 22 hour method once every week, this was not an issue.
Oct 24, 2011 — 10:12 am
I have fasted on occasion, but I try to leave it more random. The few times I’ve tried to schedule a fast, I’ve ended up spending the entire time thinking about food and, even if I don’t feel hungry, I eventually get a headache (the headache goes away once I eat). If I rely on my body’s appetite cues instead of “meal times” or “fasting times,” I end up with a varying number of meals per day at varying sizes. It seems to work.
Your first point is interesting. I am currently fighting a cold and when it hit me last week, my appetite vanished. This could be in part to the insane amount of liquid I was drinking to soothe my scratchy throat, but I went most of 24 hours without food and felt it helped. I didn’t worry about it as I figured my body’s resources needed to focus on fighting the cold rather than digesting food. For several days I ate very small meals (or skipped meals) because I just did not have an appetite. My appetite returned last night, so my very unscientific reasoning tells me I will soon be over this cold!
Oct 24, 2011 — 10:21 am
I tried IF intermittently for about a year. But my main health goal is focused on short-distance rowing performance. IF usually worsened my performances. It’s like you said – if you workout hard and then not eat sufficiently, it’s telling your body that as a hunter-gatherer, you’re a loser.
The thing is we – all of us – are descendants of winner hunter-gatherers!
I’ve just started experimenting with vegetable only fasts (nothing but fasting or vegetables and olive oil) for about 24 hours and that seems to clean things up nicely – mitochondria scrubbing and all that
Oct 24, 2011 — 10:24 am
@Ali – Recently I was certain that I was coming down with a cold. Besides my usual Vitamin D3, I also added iodine via kelp tablets and I was 100% within 24 hours. I’ve stopped colds in the past, but never that quickly.
Oct 24, 2011 — 10:29 am
@GWhitney – Well said.
I’m also planning a new IF post where I roll together all the best ideas from other plans combined with my experience. I’d call it Mentor, but I already used that name in another post.
Oct 24, 2011 — 11:01 am
I’ve learned that keeping an element of randomness in my eating habits is important. I tried to follow a strict schedule of not eating until a set time every day, but that didn’t work for me. Following a fasting schedule is still following a schedule, which naturally removes randomness.
My general plan of attack is to eat really light (or fast entirely) on weekdays and eat normal size dinners. For instance, I’ll have an apple around noon some days, a few eggs and some cheese some days, and fast entirely on other days. I generally use the weekends to feast a bit more and I’m not afraid to have brunch, a snack, and a big dinner.
Oct 24, 2011 — 7:44 pm
I’ve learned that I will likely never eat breakfast again. Or at least it will be a rare occurrence indeed.
I’ve IF’d daily for somewhere over 2 years now and rank this right up there with cutting out gluten and seed oils, and giving up chronic cardio.
For me personally, having an eating window that starts at the same time each day is optimal (you’re mileage may vary). On rare occasions something comes up and I start later, but I almost always begin eating at noon. And over the years I have been finishing my window earlier and earlier … ending about 6:30 right now. Although to be honest, I’m not hung up about when my 2nd meal ends.
I exercise in the mornings – fasted. I have done the BCAA thing (ala Leangains), and I have done without. I do not notice a difference in strength, muscle mass, or hunger one way or the other.
The biggest thing for me is just not having to think about eating in the morning. I just focus on work, and have more energy for it too! And not having to tinker with pre, peri, and post workout nutrition and timing is liberating. I just eat a nice big healthy lunch at noon. Period.
I hear you on the whole issue with our genes not being wired up for repetitive routines and eating right after the kill and all, but I’m just not going to mess with success at this point.
Oct 24, 2011 — 10:19 pm
It should be noted that often the part of the animal eaten immediately after the kill was the liver. Which just so happens to be the richest source of protein, vitamins and minerals of the whole animal.
Oct 25, 2011 — 4:00 am
I try to strike a balance between routine and randomness with my fasting. I found that imposing too much routine on my fasting stalled progress in the longer term and that too much randomness led to less fasting overall. I’m now building off of your seasonal approach, Mas, to see if I can sustain longer term progress by doing “the same thing but different” with my fasting.
My workouts are usually in the late afternoon/evening, so post-workout nutrition is easily available and meshes nicely with my fasting. I don’t concern myself with trying to optimize pre-workout nutrition, though. I only workout when my energy levels are high and I can really get after it. So, for me, I don’t think pre-work out nutrition is as great a concern. That said, I’m not trying to tease out the last 5% of my athletic or body composition goals – I’m still working at the basics. If I were chasing a high level of athletic performance and/or body composition I would be more compulsive about details like nutrient timing.
Oct 25, 2011 — 4:46 am
I have been doing daily 16/8 fast/feeding for months now. I feel good. No performance problems although my post-workout meal is larger and higher in carbs.
I am curious to see if the coming winter months will have an affect. The last few years, I had put on weight when the cold hit.
I cannot say I have found anything negative about IF… which, honestly, I would have never expected.
Oct 25, 2011 — 8:01 am
Geoff brought up a good point. I’m now at the point where I am planning to use scheduled IF this winter to tease out the last 5% of composition goals. I’m not even sure it is possible without a loss in performance. I got close last winter before I ran into problem #3 from the post.
I understand that this is not a paleo approach. For me this is a riddle. I’d like to solve it, share what I learned and then move onto another challenge.
Oct 25, 2011 — 8:04 am
Who says the average *successful* Paleo man had less than 10% bodyfat?
Oct 25, 2011 — 8:12 am
@GWhitney – That is my point. I’ve used IF to get to a healthy body fat level common with indigenous hunters. Going lower (like Leangains) would not be Paleo, as you’d increase the risk of starving, especially in the winter months.
Oct 25, 2011 — 8:15 am
I agree! Body building is definitely not Paleo…
Oct 25, 2011 — 9:44 pm
Sure it’s possible to get very lean without losing strength. The key here is to do it slow and steady. No big caloric deficits just to reduce body fat.
I have done this while meshing Paleo nutrition with a Leangains type of IF’ing and exercise intensity/frequency. I tinker here and there, but think the bulk of my success has come with being very consistent.
I think shooting for a low body fat level as an experiment and then moving on may be setting the bar to low. Look at someone like Mark Sisson … the guy is incredibly lean (especially for his age) and stays that way all year round. As do I, and of course Martin over at Leangains does too. Actually, he has a great article titled ‘the secret benefit of being lean’ you should check out.
Having said that, people are absolutely right pointing out that staying very lean is not by definition Paleo or even healthy for any given person. It’s all about finding what works best for you and your situation. When you reach your goal (and I’m sure you will) you will then be able to decide if staying there is easy enough or not.
Oct 26, 2011 — 7:52 am
@Aaron – By “moving on”, I meant as a primary health goal. I totally agree with your last paragraph. Thanks.
Dec 22, 2011 — 1:09 pm
I’m following the Perfect Health Diet – which I LOVE – and I’ve been doing Intermittent Fasting for several months now. (Fast 16 hours, 8 hours of feed with coconut oil during the fast for breakfast and eating 2 meals and a snack during the feed.) I’ve been very happy and it’s very easy – especially in the morning. One time I was in a hurry and forgot to take my coconut oil in the morning and had some mild hypoglycemic symptoms while driving to work. I won’t do that again! Between the Perfect Health Diet, their recommended supplements and IF, I feel better, have more energy and feel happier too!
Dec 22, 2011 — 6:26 pm
@Connie – I too have adopted the Perfect Health Diet approach to 16/8 fasts. I cover what I found in the post Intermittent Fasting – The No Hunger Method
Jun 19, 2015 — 11:15 am
Hey, thanks for this article. For me, I would say #4 is my greatest mistake, still do from time to time. I forget the time and then realize “wow, im hungry” and then binge after the fasting period is over. Then I kick myself for doing it. Its a love, hate 🙂