You may or may not have heard about intermittent fasting, but the real question is – does this type of fasting actually help you lose weight?
Intermittent fasting is a diet regime in which a certain period of time of fasting is followed by another time period in which one is allowed to eat certain foods. You may have heard of some of the more famous intermittent fasting regimes, such as the “8-Hour diet”, “Fast diet”, the “Warrior diet” and number of others. They all proclaim that they induce very quick loss of fat, and yet after the fasting period is over one can eat whatever they want.
So, how true are those claims, and doesn’t fasting contradict the common nutritional theory that one should eat small and many meals a day to keep their insulin levels from spiking?
Let’s go back to intermittent fasting. It involves time periods from 12 to 48 hours of fasting, which are followed by 8 to 24 hours of non-fasting. This according to the authors and followers of these diets leads to easy weight loss without the need of caloric deficit, also the loss of more fat rather than muscle as well as an easy method to keep the lower calorie intake and thus increase the weight loss.
So, how much of this is actually true?
First of all, studies of the results of intermittent fasting and other constant calorie limiting diets show that the weight loss is actually the same, and that changing the schedule and timing of meals has no effect on weight loss or the expenditure of energy. In fact there are other studies which have found that long time periods without a meal can actually hinder the loss of weight because of the insulin spike following meals and the reduced thermic effect of food when the meals are irregular.
The other claim that intermittent fasting is not actually a diet because it doesn’t involve calorie control is also not true, because there is no evidence that a person can lose weight when on intermittent fasting without counting calories, or that they will lose more weight than if following a normal calorie deficit regime.
After all, calories are an important factor, and also for permanent results, the weight loss must come from the loss of fat rather than from the muscles of the body, and there is no evidence that this type of eating leads to the loss of more fat and less muscle than a normal diet.
There is no scientific evidence that eating less frequent meals helps reduce the hunger. One study even found that eating a single meal per day increases the hunger levels, and with the increase of hunger comes the increase of irritability and preoccupation with food.
Also, fasting could affect the energy levels and the athletic performance too, so it actually doesn’t have an effect on the calories being burned. Previous studies have found that Muslim athletes generally perform worse during Ramadan, when no eating or drinking is allowed during the day. Of course, the performance and mood of a person during fasting differs in different people.
One thing which is good about the reduction of the daily meal frequency is that this allows for better control over hunger, and gives a better structure to the diet.
Overall, intermittent fasting will cause weight loss, and for those who can strictly follow this type of eating and fasting regime, the results could be quite satisfying.
Unfortunately, because of the side effects from fasting, including: headaches, constant hunger, bad mood and irritability and problems with concentration, few people have the strength and will power to keep up with this type of diet for a longer time.
I was almost caught up in the hype of intermittent fasting then realized the above. I did try it and did not like it.
I first tried skipping breakfast for a few days. The result was: I was tired, irritable, no energy to workout on the same amount of calories as If I would eat normally. I have more energy and less moody etc on same calorie amount spread out over 4 meals a day . I also used to do 6 meals a day for a very long time, I have now found 4 is better for me. They always say don’t do something you can not maintain for life and there is no way anyone can do any form of intermittent fasting for the rest of their lives.
Another reason that some people practice intermittent fasting is the research suggesting that it can function as a caloric restriction mimetic in the sense of improving lifespan and health span at lower, or perhaps zero, actual caloric restriction. It is hypothesized that the resulting lowered average IGF-1, insulin, and blood sugar are major mediators of this effect.
However, since caloric restriction often occurs implicitly with intermittent fasting, it is not totally clear the results are independent of intermittent fasting. I hope to review this literature in the near future to reach a clearer conclusion.
I am on lean gains style of intermittent fasting going on two years and feel great.
I have gained strength and lost fat doing it his way. I totally enjoy my freedom of having two really large meals a day and be done with it. Beats the 8 a day style i had before.
I think intermittent fasting is basically an easily followable set of heuristics that allow for a sustainable calorie deficit. There might also be some partitioning advantage for shifting most of your food to the post workout period.
Smaller meals work way better for me. And you don’t need to feel full after a meal, ever. Calories in calories out, that’s all that matters.
I would argue that calories in, calories out are not all that matters, and quality of food and timing of food can also factor into one’s results.
I would also argue that getting to a low body fat percentage is dependent upon far more than “stop eating.”
Strength training, getting strong, and intermittent fasting don’t have to be mutually exclusive.
I am on the Carb Back Loading & Paleo team at the moment, very happy with the results, but I also cut some meals from my schedule on the last 2 months. From 6-7 means I went down to 4-5, an things are doing great. I would like to experiment intermittent fasting one day though, but first i would like to see how things go with my current plans.
In my late teens/early twenties I read “Fasting Can Save Your Life” by Herbert Shelton and used this info to fast one to two days each week. Once I fasted eleven days on just fresh veggie juice and had tons of energy during that time. I had no problems with hunger – just told myself I was not going to eat.
I thought this was beneficial to my body, but over a few years of time began to see negative things – enzyme/pancreatic and peristalsis issues. My body seemed to be struggling. Perhaps I wasn’t drinking enough water. Hence, while I often do still skip meals when not hungry, I’ve now decided not to fast for an entire day on a regular basis. I don’t have diabetes, and often go hours without regular meals with no problems. It’s interesting how fasting can often de-stress the body, cleanse and rest the digestive system; while other times your body tells you it needs food. I’m over forty now and go with what my body tells me.
I am so glad more people are reading about intermittent fasting!
I’ve been fasting since January and my way is a little different from these but similar. I eat very paleo, as much as I want, whenever I’m hungry (usually 2-3 meals) and they are big!
However knowing the food going into me is healthful frees any reservations of portion size. Then on Sundays I do around 35 hours of fasting. I fast from my last meal Friday night, the whole 24 hours Sunday and however long I sleep Monday. I finally eat after my workout Monday morning. It was tough for only about a month but now is quite normal for me (just a coffee on Sundays).
Friends find it crazy but I find too many benefits from doing it: overall calorie intake down, used to combat a weekend evening where I partied really hard, and it really helps my expenses (being on a budget). Definitely try one of these methods!
Most examples of intermittent fasting are based on the theory of fasting overnight and into the morning, working out, then immediately begging the feeding window. Do you have any advice for adopting the principals of intermittent fasting when my workout window is around 6pm at night? Adopting a feeding window from 7pm to bedtime would make me very cranky during the day at work (plus my wife would lose it).
I had modified my diet to this about a month ago after reading about Ketosis. I wake up (6am) and within 30 minutes I eat breakfast and coffee. Breakfast consisting of 4 eggs with a bunch of bacon. Then after softball I eat dinner (8pm’ish), usually steak or chicken with steamed veggies. Doing so I had lost 17 lbs in a week and a half.
However after stumbling, with bad choice of foods to accommodate the wife’s desires, but keeping to the schedule, I had stalled. Beforehand eating the same foods I would be gaining weight whereas now I stay put on the scale.
Anyhow, great article and is motivating me to get back on track with the proper nutrition and stick to intermittent fasting.
I am a woman and have been very successful with intermittent fasting as it is described on LeanGains, where it’s recommended for women to do a 14 hour fast.
For me it was more the mental side, rather than the weight loss etc side. I have been obsessive about food and this was the best way for me to overcome it!
What I did though, is tackle it in steps!
First I went from eating snacks, to not eating snacks. My breakfast and dinner stayed the same, and I added some more food in at lunch time.
After I was successful with eating 3 meals a day, I started to try fasting on my weekends. I would record the time of my dinner and aim for “as long as possible”. I would be hungry in the morning, I would know when my 14 hours would be up. I would drink water to battle the hunger. First I got to maybe 11 hours, then 12, 13, 14. On weekends it’s easier for me to not start the day with food, since I can just “be lazy”.
Once I was successful on the weekends and that had become easy. I moved on to taking breakfast to work and delaying that as long as I could.
Finally I did 14 hour fasts every day. I still ate breakfast, lunch and dinner though. I ate less breakfast as it was fairly close to lunch.
I then went to New York and this eating plan kind of fell into the water, but I’m working my way back to it!
What it really taught me is that, no I don’t need food all the time. This realization, and most importantly, not just knowing, but experiencing it, is what broke my obsession with food .
I started intermittent fasting a few weeks ago and have loved it!
My biggest takeaways are that 1 – its way easier than you think and 2 – it makes mornings a heck of a lot simpler! I skip breakfast every morning (with usually 1 exception per week or Saturday or Sunday) and it has been helping me simplify my day and do something else to supplement my quest to eat healthier and get stronger.
I can see how this makes sense and it is not outlandish. People use all types of dieting techniques around the world. But for those of us who have force fed ourselves all throughout life because we’ve been told repeatedly that skipping breakfast is wrong, this makes me want to hang my head and cry. But I won’t.
However, it does stand to reason that since you are offering the complete opposite of typical dieter’s advice that maybe neither techniques are necessary to achieve a high level of quality health and fitness. There have to be rules of course such as eating directly after a workout. That is obvious b/c after a w/o, your energy is depleted and your body will store calories most optimally at the time, but here is my question:
Why can’t I just eat when I’m hungry?
Currently, I sometimes have to force feed myself, not because I’m not hungry but because I don’t feel like eating. From what you are saying… this is not necessary. Other than post workout, as long as I don’t binge, I can eat whenever I feel like it only, as long as my meals are well thought out. Plus, I can keep simple fruits and easy to eat raw veggies around for when hunger suddenly engulfs me mentally and physically.
This is good news if I am thinking correctly because I am also a chef, and I definitely feel that food tastes so much better when you are truly hungry. If I eat when I want, I will typically not eat until five pm and I will eat one good size meal and drink water until I am comfortably full and I may have something sweet. If I have half a serving of whey protein before a w/o, I have plenty of energy to finish.
I am up for intermittent fasting but I really only have time for breakfast and lunch. Due to my work I usually don’t have time to eat more than a snack between 1:00 and 8:00pm.
I have been gaining weight in part because I am usually famished when I get home and end up eating garbage and way too much of it. I am brand new to the and site working on making a change toward healthier eating and I am now also wondering I could start with a healthy breakfast and a decent lunch and fast for the rest of the day. Any thoughts?
I’m completely new to the concept of intermittent fasting so this was very interesting to me. I typically have been doing all my runs/work outs in the evenings but have recently managed to wake up and do these before work (and by recently, I mean this week was the first time!).
My question is, if I want to run at 7am and then have to skip breakfast and not eat till nearer 12, how does that fit in with the theory that you should try eat 30 mins after a work out to maximize how your body processes the meal?
Thanks again!
I’ve spent the past six months just focusing on weight lifting, nothing else. Just sleeping or eating whenever my body wants to. I’ve gained about ten kilos, but my clothes all fit the same and my blood stats are all fine so I haven’t been concerned.
I have considering cutting, but this is an awesome reminder about how good intermittent fasting is. I was doing it for chunks of last year, never really lost much weight but it still felt pretty good. One of the most beneficial things for me was just learning to be hungry and how to deal with hunger. I used to get SO CRANKY when I didn’t eat, and now it’s like “Cool, don’t have time to eat, that’s okay.” And just push it aside until later.
Definitely going to get back into it and see how I go.