General IF and Reader Q&A
To lengthen thy life, lessen thy meals.
Benjamin Franklin
I wanted to go over the most often questions I hear/read about IF and how to use it. This could also be a great starting point for someone just trying it out as well as for the more advanced people.
Q: What is CR and IF? How are the 2 related?
A: CR stand for calorie restriction where you basically eat less calories every day compared to your “normal” eating requirements. This could be as low as 30-40% less than average. IF is not the same as CR. IF is intermittent fasting where you fast from all foods (just water) for a defined period of time. On your days where you are fasting you are eating less foods in a smaller time window…..so in a sense it is a form of CR for that day (as you would probably not eat the same amount of calories in a full day of eating vs just having 6-8 hours to eat). It is not as drastic as the 30-40% lower in most cases, but does provide for an overall less calorie intake when you average your days together. IF provides all the benefits from a CR plan with the additional benefits that come from fasting (that eating all day can not, even if very little). Namely better responses in fasting blood glucose levels, fasting insulin levels, reversing insulin resistance and other cellular protective responses (heart, lungs, brain).
Q: What are all these new diet books about every other day eating?
A: Ok…this is my own personal question but you will start to see more books on the “miracle” diet of ADCR, or alternate day calorie restriction. I know of one book touted to be in major book stores soon with selling the idea of “eat anything you want one day….and then eat less the next”. Basically promising people they can eat anything while still losing weight. Although not healthiest way, but can work for the general public. But is it really sustainable,? Probably not. Here I will save you the $29-$49 for any ADCR or ADF (alternate day fasting) based book. Step 1: Eat one day, Step 2: Fast or restrict calories the next day (in the case of restricting calories they say eat healthy with fruit and vegetables), Step 3 repeat Step 1 and 2. Done. Pretty simple huh? Like I said, can work for the general public who have alot of weight to lose, but at some point weight loss will plateau and then you can not get away with it anymore. Hopefully at that point someone doesn’t get depressed and then go back to their normal eating habits and balloon back up (the inherent danger of EVERY diet book or plan). That is the problem with any diet saying you can “Eat anything”, as that is not a lifestyle plan and does not solve the basic problem. If you eat for health, you will get the weight loss and be able to create a lifestyle around it. So focus on healthy eating first, fasting or CR second.
Q: I am new, how do I IF?
A: Of course I would first say read my post on IF 101. To sum up quickly you can daily fast with a small eating window every day (my choice) or you can throw in a longer (24-36hr) fast 1-2x a week. Which is better? The one you can effectively and consistently fit into your lifestyle! People who are more active tend to do well on the weekday small IF windows, while people who are not as active may do better with adjusting to the longer fasts 1-2x a week. No matter which one you choose, I still say the #1 factor is still going to be quality foods….not doing IFOC (IF on Crap). You will not get the benefits from IF eating junk or sugar during your eating window and may even gain weight. Quality of foods first, and then IF just adds more results. Smaller meals in the IF eating window also are better than just one big meal, so break it up and make sure you are getting quality protein with every meal.
Q: So which fast is best for overall health?
A: Longer fast will have more direct impact on being able to deeply detox and rebuild at the cellular level vs doing a brief fasting window daily. While I personally like the daily IF to keep performance levels up and maintain/gain muscle while losing fat, I also plan to more routinely add in a 24-36 hr fast at least once a month for that deeper health benefit. Again there are no set rules to IF, you make what works for you and can always adjust it from week to week. The main factor is consistently, what will you consistently do in your lifestyle and still keep you happy and stress free.
Q: What about drinking a shake pwo? (post workout)
A: Short and simple, you don’t need it. Eat a whole food meal 60min after a workout of protein and carbs. Unless you are a professional athlete, train for hours everyday or have a huge volume of training and recovery needs, you are not needing that quick glycogen loading window. If you want to play with just BCAA supplementation pre , during or pwo for muscle building, then that could be of benefit. But avoid the sugar spikes. Plus around here for longevity we stress the fat metabolism for fuel, so glycogen replenishment is not as big a factor once we can adapt to a fat based metabolism. You will replenish your muscle glycogen fine over a couple of days. Avoid the insulin spike esp if fat loss is your #1 goal.
Q: For a higher fat diet, where do I get “healthy” fats?
A: Best sources will be the healthy sat fats (steaks, eggs, butter…from 100% organic grassfed animals ideally), MCTs like Coconut Oil, and Monounsaturated fats like X-virgin Olive Oil and avocados. Other EFAs include some Polyunsaturated fats in the form of Omega 3s and 6s including Fish Oil, Nuts and Nut butters (Almonds, Walnuts….Peanuts are NOT a nut, they are a legume). You should limit the amount of Polyunsaturated fats (esp cooking in veg oils) as they are highly unstable and cause more free radical damage to the body/cells (throw away that margarine as it may increase your risks for cancer!). Trans Fats should be avoided at all costs.
Q: How does drinking lemon water (lemons which are acidic by nature) actually increase the alkaline ph of the body?
A: It’s not so much the acidity of the food in it’s natural state that matters, but it’s net effect through digestion on the body’s overall ph. In this case, citric acid (from lemons) is something that may start acidic but through digestion and utilization in the Krebs Cycle (or Citric Acid Cycle) helps to turn the body more alkaline. (Hence why lemon juice and vinegar can be healthy for you) Here’s a pretty good overall more detailed explanation. “The Citric Acid Cycle, being able to free hydrogen ions of its electron is also one of the major buffering systems of the body. ”
Q: Do I shake Kombucha?
A: Ummmmm……Sure…..just make sure you do it and open while you are driving in your favorite shirt and pants! 
photo by wok
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Hi Mike,
Great Blog..I read many of your articles yesterday and though of giving IF a try..today is my first day on IF I am going for a 16hr fast. Had Dinner at 9:00 PM yest and planning to take next meal at 1:00 which is just 10 min from now.. I can control my hunger but I am having a bit of urge to eat as I am used to eating a big breakfast within 1hr of waking up..I am thinking of trying 16hr fast 3X a week .
Bit of concern for me is that I mostly follow Vegetarian diet so I think it will get tough to have large amount of protein in a short window of time on a vegetarian diet…
Harsh – Yeah the cravings can be hard at first…but then I find myself enjoying the mental clarity and feeling on the edge with some little hunger during the early hours. I find that caffeine does help repress some hunger (such as having a small Americano in the morning). Do you normally eat as late as 9pm at night? What time do you go to bed? Most cravings come up later at night and going to bed late may also lead to more cravings in the AM. (It has all to do with cycles of melatonin, GH and other hormones that are more naturally regulated when people sleep from 10pm-6am…if you want a good book on that read “Lights Out:Sleep, Sugar, Survival”. Also if your diet is primarily carbs, that can also increase cravings and hunger as a primal response signal for the body to stock up on carbs during the summer months to fatten up and survive the winter months where foods are less available. People on diets higher in proteins and healthy fats have less cravings. As for the vegan thing, well I can try and convert you but it’s your choice of course.
You do need amino acids and that is key. Veg sources are little compared to meats of course. Other options like eggs (although I don’t believe you eat those correct) and dairy (but I am not a fan of excessive dairy as it is a common allergen…especially the processed/heated versions today). Whey protein could be a help, but supplements are never the same as getting whole foods as whole foods take hours to digest and give a steady stream of amino acids for your muscles to use. Whey gets adsorbed way too quickly, a better choice would be egg or casein based protein powders.
Hi Mike, Thanks for the response…One think I notice was that I was not at all sleepy, which I usually am after Saturday’s breakfast. Unfortunately I return from work at around 7:15 and work in gym from about 7:30 to 8:30 so 9:00 PM is the earliest I can have a dinner. and I go to bed at around 11:00….Lol no need to convert me
I eat aprox 3 eggs in breakfast , 500 ml of milk, cottage cheese daily and maybe chicken once a week.where I live (India) eating flesh is not that prominent and its a bit tough to eat chicken on daily basis..Main source of protein for me are eggs, dairy product, legumes and lentils, nuts, whey supplement and very little soy. and my carb intake comes only from fruit, vegetables and whole wheat.
Harsh – You may want to switch up your protein powder so something thatis not 100% whey (that is just too quick to digest and you want something a little more slow released during the day). Look for Casein or Egg based powders if you can. I know what you mean about sleepiness after a large meal….most people are and that is not a good thing. Worst case if you make your nightime your biggest meal at least you are close to going to sleep anyways. Digestion takes up a ton of energy. One of the main reasons I love IF is the ability to keep meals very small and energy levels high and consistent through out the day.
Mike OD, My workouts are performed in the mornings before work and my eating window for IFing is 1-3pm to 7pm. Do I need to skip the IFing on my workout days to get the meal in 60 min. after my workouts or can I wait until my eating window and still get the muscle building benefits from working out and the fat burning benefits from IFing on the same day?
Thanks,
MikeB
MikeB – What kind of workouts are you doing? I am assuming strength/hypertrophy based ones? (reps 5-10 for most sets?). Also how many times a week are your working out? 3x? 5? In general, remember that you build muscle 24/7. The pwo window is just an opportunity to take advantage of the insulin sensitivity and ability to intake more amino acids for rebuilding and glycogen for muscle storage through the delivery agent of insulin. But if your goal is fat loss then you are potentially blunting the GH response from an intense workout that can burn fat. If you are already following a lower carb diet and keeping insulin levels steady, then you are doing alot for your insulin sensitivity right there. Unless you are doing alot of volume in working out and need quicker recovery for performance, then you should be fine till later in the day. Again muscle builds all day long…hence why it takes 3-5 days after you really workout a muscle part to go at it again. If you want to try anything, you can play around with some BCAAs pre-workout. Otherwise make sure you are getting enough protein in during the feeding windows. I aim for 1g of protein per lb of bodyweight when I am trying to build muscle….and yes that is alot to eat especially when you add in IF. Most people don’t need pwo drinks unless they are doing very high volume training. That and unless you get your bf% low enough and improve that insulin sensitivity you will end up just putting on more fat than muscle. In the end, you can play around with the eating hours and see what works best for your recovery needs, energy, and muscle building. I’d say goal #1 is getting enough protein in your eating windows during the day, so worry about that before you start sweating about pwo. PWO eating is overrated compared to the importance of getting in enough protein daily as there are plenty of big strong people in the world who never heard of a “pwo supplement”.
Thought you’d be interested in this short omega-3 video: http://www.youtube.com/watch?v=eIgNpsbvcVM
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Susan – That is great! Too bad the rats are getting smarter and humans are getting dumber! lol. Seriously…EPA/DHA deficiency (along with inflammation from too many Omega 6s) is probably the common/biggest factor when it comes to Alzheimers, ADD, Autism, Depression, Seizures, MS and any other brain related disorder. My next post will probably be on Omega 3s and healthy brain function. Thanks.
MikeOD, Thanks, I appreciate the thoughtful response. Right now my daughter is in a Girls on the Run program at school (she is 9). I have never been a big runner but decided to run with her in their 5-K on April 20th. I have been running three days a week and doing a strength workout one day a week from Ross Enamait’s book Infinite Intensity. I also cycle a couple of days a week. I keep the cycling to about an hour and my longest runs to 6 miles the other runs focus on recovery and speed training. I also compete in cyclocross in the fall. Cycling, cyclocross and running punish you for carrying extra weight, so there is a balance of gaining muscle and not gaining fat but increasing performance and the fact that I am 50. I felt that the PWO drink was somewhat overrated. I think for now I will stick with my current program of not eating until after noon and focus more on protein intake and and see how it goes. Most of the time my diet is clean and low carb so I believe that I am programed to burn fat. Even though I and 6′ and 170 lbs people still tell me I need to gain some weight. As of yesterday I am fighting off a cold/flu virus so this week will probably be just an easy week. Thanks again for the response.
MikeB – Like I said above, protein during the whole day is a bigger factor than pwo drinks…unless you need quicker recovery to go again (like playing sports day after day). But that is assuming one is also a glycogen burning machine and not fat adapted metabolism. If you feel “drained” or run down, add some more fats in during that day to get your calories to match your activity level. Colds may be a sign of compromised immune system so make sure you are recovering for your activity level. Don’t be afraid to try a day of eating whatever and whenever (usually works best on the weekend). A good way to make sure you are not letting your metabolism (and other immune functions) drop too low. Also keep in mind that your “type” of training will matter. When you talk about GH response then you are generally talking about shorter/higher intensity training with sprint intervals or weight training. Nothing over 30-45min. When you talk about other type of training that is 45min+ and more “aerobic” by nature you do run the risk of increased cortisol and muscle loss. I would say eating after a longer type of training is important to shut down cortisol. Cortisol is going to be on the rise after about 45min-60min of aerobic style of training. That and you do not get the GH response from intense shorter training that serves to help preserve muscle. So in short, eating whole food proteins/carbs is going to play a bigger role after longer steady state aerobic training to stop muscle loss.
Well first off I’d like to say I love this site, I stumbled upon it after someone posted a link to it on a forum I was on. Needless to say I had been doing IF for a few weeks prior to that and loved it. I still do it to this day, still learning what works for me and what does. I had an important question, and I’m hoping it can finally be answered. I like to workout early in the morning, when I mean early, I mean 0400 early. Now most people that I know who do IF tend to workout in the evening then follow their workout with their main meal(s). Some note saying that eating later in the evening produces more sound sleep. I’ll be honest, I slept way better when I had been fasting for some time. I tried the Warrior Diet, which is essentially IF with some variables applied. Still, they go on about working out in the evening and eating soon afterward. Sorry to drag this out, but if I workout early in the morning and had my main meal(s) directly after that, or within a short window following that, would I see the same benefits as those working out at night and eating at night? I usually workout in the fasted state, have a protein shake and fast until the evening where I eat my main big meal(s). Though my sleep is uneasy at best, I wake up often, sometimes I even feel wide awake and don’t sleep for hours until when I usually do. I never see anything in regards to those who like to workout in the morning specifically, so I hope you can answer this question. Thank you, I love this site, keep up the great work.
Quick question. Right now I am doing Paleo/IF TuesWedsThurs and Paleo the other days in small meals. I however do double days of training with weights, sprints, HIIT, and grappling. Basically I have a workout in the middle of my fast, usually light grappling or sprints. What to do?
Jonathan – Honestly sounds like you answered your own question. If you are sleeping better with your eating schedule, then stick with it. Sleep is so important for the GH release and other health benefits. Waking up often is a sign of either screwed up cortisol cycle and/or no deep sleep stages (which means blunted GH release). You could also play with an IF day on the weekend if that makes more sense for your schedule.
Ryan – I’m a little confused by your workout schedule and how it is layed out, but it comes down to getting enough calories in to recover. If you performance is good and you are seeing good results, then you are where you need to be. If not, chance are you either need to learn to eat alot more in your eating windows or stagger the IF days differently.
G’day, very interesting and informative site. Two thumbs up!!!
I started keto a while ago and while searching the net for more information I came accross Paleo and IF. I impleted both into my keto diet and so far so good. I like the IF and it is going pretty good. Even though I read a lot on numerous sites I still am not sure how to implement the IF into my daily life. I thought I would start with the 5-Fast way, therefore I fast from 9pm to approx 3.30pm the next day. Drinking only water while fasting. I work out from 5ish pm to 6ish pm after work. Sleeping time is 10pm to 5am. I would like to work out fasted but then my eating window is really small – like from 7pm to 9pm and I have to fit in approx 1500 to 1800 cals. This is too much, even though I try to fit those into 3 meals. Have you got any suggestion for me?
Also I am an lacto-ovo-vegetarian since many many years. I would like to give up soy products which leaves me with eggs and cheese (not paleo friendly). But I cannot eat eggs and cheese for the rest of my life. How would you convince me to start eating meat again? What benefit would I get out of it?
I appreciate your response and keep up the good work. I make sure to be a regular visitor.
Cheers and have a lovely day.
Ursula
Ursula – You don’t have to do IF every day, so make what works for your schedule. If you want to eat around your workouts yet try to be fasted, just have a meal 3 hours before the workout….and then an hour after. Use that day to eat all day and non-workout can be standard IF days. Remember, make it work for you. As for eating meat, well there is no reason to assume it is not healthy for you…if you have another reason for being vegetarian not sure I can help argue that. You want variety in diet, and not eating meat will lead to issues with finding variety and making sure you get all the amino acids your body requires. Your body needs amino acids, muscles require them. This is a good site that may have more than enough info you could ever need.
http://www.beyondveg.com/cat/frank-talk/index.shtml
Hi Mike,
Thank you so much for getting back to me so quickly. Appreciated. And thanks for the link. Seems like I have to do a bit of reading, again.
Question: I’m wanting to do IF, I think I kind of do it already by eating in short spans of times during the day. Typically I usually eat 8-3 pm or 4- 10 depending on my schedule. But, in the times when I’m not eating, I drink tea or coffee with milk in it. I’m not consuming more than 50-100 calories with my nonfat or whole milk, but does that break the benefits of IF by consuming any calories? If it does, I can probably stop drinking the milk in the tea in the afternoon. (I can’t actually imagine consuming coffee without milk though.)
But maybe it’s enough just to try to eat between 8 and 3 and then stop and not worry about the coffee in the mornings on the days when I eat late. Thoughts?
Thanks for these informative posts! They are great.
JK – dump the milk, coffee is fine. Add in something other than milk if you can’t drink it black….like heavy cream if you need something. Milk gives a pro-insulin response in the body, not something we are trying to achieve during fasting. Once you break the fast and eat, then it’s up to you what you put in your drinks…although I would still say dump the milk and move to more creams (which have more fat, less sugar).
Hello and thank you for the informative posts. I have been following the discussion for some time.
I run marathons, and was hoping you might be able to advise on your thoughts about IF on long run days. Last week, I ran 30 km in the late morning (without eating first) — then delayed eating until 5 p.m. With long runs, I actually find that I am not the least bit hungry afterwards — I could have easily made that a 24 hour fast day, but was not certain that was healthy (?). I realize that running is also supposed to spike HGH (especially in a fasted state) — but was not certain about fasting after long distances.
Do you have any advice for those of us who are distance runners who also want to benefit from IF?
Mike!
on your response to the question of PWO shakes: what if I’m a high volume athlete that trains nearly everyday? PWO shake with a “fast” acting sugar ie: Dextrose or Waxy Maize with Whey Protein?
shake pre/during the hours of training? or only BCAA’s?
don’t I want the insulin spike with the added protein after a extreme type of workout?
I swear i’ve read reports stating this is the way to do it?
thanks
Martin Berkhan Reply:
Unless you’re training twice a day there is no need to worry about high GI carbs.
Restoration of muscle glycogen will be identical regardless of carb source unless the second bout occurs 8-12 hrs after the first. This is a topic that has been extensively studied. The fact that people training 3-4x/week are downing PWO-shakes with wazy maize or dextrose to facilitate recovery is completely absurd.
Mike OD Reply:
Pre-training spike is a bad idea, as you will crash your blood sugar later (and drop performance). During training, all depends on what kind of training, how intense (sprinting the whole time, slower paced activity, mixed) and how long it is total. Generally as long as you are eating correct beforehand (24-48hrs) then the body will have enough glycogen stored in the muscles for most activities. If for some reason you are feeling bonked or drained, you could try using some BCAAs in a small amount of gatorade/water mix to stabilize blood sugar. Personally I do fine with water for any activities (ice hockey game, training in gym, mountain biking) for up to 60-90min, having a little caffeine beforehand also gives me a boost. The only real bonking I have suffered from in the past when I was eating more low carb and also trying to do competitive events, didn’t work out good.
I’m not a fan of wanting to spike your insulin/blood sugar for any reason. As the body works long term and can replenish muscle glycogen good enough on it’s own with real foods. Look at how many professional athletes do not purposely spike blood sugar, most all of them. If you want to eat more carbs (from foods) after a workout, then go ahead.
Yes there are “studies” to promote pwo spiking, but most are misleading as they don’t paint the whole picture of 24hr+ recovery (and are funded by supplement companies who have their own results they are looking for). Read the part in this article entitled “forget the pwo insulin spike” and hopefully it clears it up.
http://www.fitnessspotlight.com/2009/12/08/secret-build-big-muscles-hardgainer/
Troy Reply:
Mike,
thanks once again for your detailed explanations, and you put in layman’s terms so i can understand too!
I’ve read the link you posted (thanks for that) and it just blew my mind. My head is spinning from what I “thought” I knew for the past 15 yrs to now!
Do you feel that probably the only and best time to purchase whey protein is when you probably can’t get enough of your daily requirement of protein?
I could be just extremely lazy too, but all the prep work in preparing foods sometimes does not fit my schedule too. so much easier to grab a shake and go!
thanks
Mike OD Reply:
Yes, you can use protein powders to add some extra protein to your diet to meet your needs, but you may not need as much as you think either. About 0.8 x lean mass is good enough for most active people, the rest is about calories after that. Doing excessive protein doesn’t mean more muscle and usually just means more protein oxidation, as your body can only use a certain amount…the rest will just get burned up. All you really need is about 1 scoop here and there…not 3-4 scoops per shake. That is a waste of money doing that. Here’s some other insight into protein: http://www.fitnessspotlight.com/2009/11/10/how-much-protein-per-day-build-muscle/
Also fun to note this study…which says whole (not skim) milk is probably the most effective pwo recovery drink (for protein synthesis purposes)!
http://www.ncbi.nlm.nih.gov/pubmed/16679981
Hi Mike, all,
I found out about IF only recently, got the first e-book, and after going through it (also went through some articles on the wikipedia article on IF) – and decided to give it a try. As I am writing this, I am on my first day of IF ever.. A bit excited..
Since I do my gym workout around 7pm, 4-5 times a week, I decided to go with more frequent fasting approach. So, what I am thinking of doing is eating around 5 pm (healthy choices of course), then again eating prot/carb after workout. Hopefuly eating only 2 hours before working out (after not eating since 11pm yesterday) will not affect my performance in the gym. I am doing 8-10 reps, with fairly heavy weights, plus cardio after weights 2-3 times a week (HIT cardio for that matter).
Tomorrow is a non IF day, so I will get a breakfast arounfd 10-11 am, and see how it affects me (is a bowl of cereal a smart choice? hmm). Then again on Wed, planning on doing what I did today.. and see how it goes from there…
Sorry if I am rambling, I am just a lil bit excited, and have this incredible crave for a big juicy steak at the moment..
And forgive any spelling mistakes, I am European after all!
On a side note, Mike, I visited your FB profile, and stole a quote from Star Wars – I now have it as my FB status..
You know, the Yoda: “only what you take with you” quote.. :p
Thanks to all for reading, any advice is welcome
Your friend in IF – Vlatko
Mike OD Reply:
Good luck, see how it works out. You may also want to experiment with using IF on your “non” weight training days (if you do those 3-4x/week….as I wouldn’t see a need for anything more than that). In the end, remember IF is just a tool…..so see what works best for you and your goals.