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Intermittent Fasting for Weight Loss

male with six pack absIntermittent fasting seems to have garnered some attention lately. I’ll admit that when I hear the words “fasting” and “weight loss” in the same sentence, I usually look the other way. However, I’m open minded to new ideas, so I read up on it and implemented it into my own lifestyle. Much to my skepticism, the results have been better than expected.

What is Intermittent Fasting?

Intermittent fasting is when you eat and then fast for a period of time. Some people follow a 20/4 (20 hours of fasting, and 4 hours of eating), and others follow an 18/6, a 16/8, and anything in between. Some people even do a full 24 hour fast once or twice a week. I chose to stay conservative and give the 16/8 schedule a try.

So basically, I would eat for 8 hours out of the day and then fast for 16. I would still eat all my calories during those 8 hours, I just wouldn’t eat anything the other 16. This really wasn’t a difficult transition for me. I would basically wake up and take the kids to school, post an article, and then do my work out. Then I would eat around 10 am. For the next 8 hours I would have 3 meals (sometimes 2), until 6pm. Then I wouldn’t eat again until 10am the next morning.

Benefits of Intermittent Fasting

There are many benefits of intermittent fasting. Some of these include:

  • Stop Obsessing About Food – I’m a self-proclaimed food addict. Not so much an addict of eating bad food (although I do love it), but about eating on a timed schedule, eating the right macronutrients, and beating myself up when I miss a meal. Intermittent fasting has put that obsession to rest. I now eat when I feel like eating, and I even skip meals if I’m not hungry or too busy. I just make sure that I get enough calories for the day, and I get enough protein and carbohydrates to rebuild muscle and fuel my workouts. Some essential fatty acids (EFAs) here and there, and I’m set.
  • Increased Time in Fat Burning Mode – By eating every few hours, you are keep your insulin levels elevated. While fat loss can still occur with elevated insulin levels, the higher they are, the less fatty acids can be mobilized. Going 16 hours without eating gives you a nice long window to burn fat in a favorable metabolic environment.
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  • Increased Growth Hormone Levels – Since I stop eating at 6pm, my growth hormone (GH) can be released throughout the night in maximum amounts without interference from insulin production. Growth hormone is anabolic to muscle and catabolic to fat. In a study measuring the effects of fasting on growth hormone levels, fasting showed a marked increase in GH [1].
  • Improved Insulin Sensitivity – Going 16 hours without a meal increases my insulin sensitivity. Because of the diminished glycogen stores after the fast, my cells are primed and ready to absorb any glucose that enters my blood stream. It does this with less insulin, which means I’m more able to release fatty acids. A study comparing the effects of intermittent fasting (IF) with continuous energy restriction showed that IF lowered insulin resistance, as well as lowered leptin, LDL cholesterol, triglycerides, blood pressure, IGF, and fasting insulin levels [2].
  • Not as Hungry – Instead of eating 5 or 6 smaller 400-500 calorie meals spaced evenly throughout the day, I’m now combining 6 meals into 3. This has given me the added benefit of filling me up so that I’m not constantly hungry. I’ve noticed a very large reduction in hunger.

There are many other studies on intermittent fasting that have shown benefits in the fields of life extension and fighting cancer. As research progresses and time passes, I suspect that there will be a number of new benefits discovered for intermittent fasting.

How to Implement Intermittent Fasting for Weight Loss

Alright, so perhaps you’d like to give intermittent fasting a try. I could write a whole book about it, but I’m going to simplify it down for you. Take 10 times your body weight in calories and eat them all within the fasting schedule you decide on. I’m a fan of the 16/8, but you could also do 18/6, or even 20/4. You can eat them all in one meal, two meals, or more. Just make sure you get in all your calories and you don’t go over. Go with how you feel. If you feel really hungry, have a bigger meal. Not so hungry? Wait a little longer and have a bigger meal later. Keep your foods coming from whole foods, stay consistent, and the weight will come off.


I need to go ahead and put this out there because people will believe this is the best way or only way to lose weight. Intermittent fasting is just one of many different ways to lose weight. The best way is going to be the one that best fits into your lifestyle. I found intermittent fasting to be the perfect fit for my lifestyle, and I’m going to continue forward with it whether weight loss is the goal, or I just want to maintain my current physique. I’ve taken blood tests and body measurements and will periodically check on them to see how things are progressing. What about you? Have you or people you know tried intermittent fasting? What was your/their experience?

  • Noah

    Another great article! A question I pose just for discussion is how I.F. works with carb cycling, and with that, if your low carb days were high fat days for a small ketosis-like metabolic shift.

    I’ve personally been playing around with this for a few weeks. The high FAT macro nutrient balance I’ve had on my low carb days has kept me VERY full feeling, so i really only have 2-3 meals that day and sometimes have a difficult time getting all of my calories in for the day (hence the I.F.). I have not lost much “weight” but I can tell you I have gotten A LOT leaner. This is one of those times when the scale is useless and how clothes fit and measurements and really just your appearance in the mirror are the indicators of success.

    Any thoughts Coach?

    • Coach Calorie

      Hey Noah, I actually was going to go into a bit more detail on IF in a future article, but since you asked, here are my thoughts.

      I’m actually combining carb cycling with IF right now. I do 2 low carb (trace carbs from veggies) days, and then a high carb day. I’m eating about 3 meals a day. On the low carb days, I am eating high fat and 1 gram/pound of body weight in protein, and getting in around 8 times body weight in calories. Then on the high carb days I’m getting about 15-16 times body weight in calories, and I’m getting all my carbs in my final meal.

      I’ve felt this has really kept my metabolism humming along, and I’ve notice I don’t have any hunger issues.

  • Matt

    Glad to hear you had a positive experience with IF!

    I know it makes my life easier, and using it along with cleaning up my diet I have dropped about 54lbs in the past 6 months, and I don’t really feel deprived and I haven’t counted a single calorie yet. As long as I am getting in my good workouts each week my fat goes away, if I don’t I seem to maintain really well or possibly recomposition as my clothes seem to keep getting loser even when the scale stays the same. I still have 15-20lbs to go, and suspect I’ll have to tighten things up at some point, but so far so good. I think the IF helps keep my schedule intact as well as somewhat focuses my fuel burn to fat, but its the overall low insulin levels from my overall diet that is probably burning my fat.

    The carb cycling is intriguing, but I have essentially been eating low carb/low GI except for immediately post workout. Post workout (of a significant workout) I have some carbs (sugar) with protein because the muscles are sensitive to insulin, non workout days I try to stay low carb/low GI the entire day. I lose more fat if I keep the carbs out entirely, but refueling keeps me working harder and I can still lose the fat. I haven’t really hit performance walls this way like I used too when staying low carb 24/7, and I don’t have to strictly monitor my calories like when I used to have 50% carbs in my diet. I simply eat the foods I eat when I eat them, and let it all work itself out.

    Keep us up to date with your labs and experience, mine have always looked better on IF then off.

    • Coach Calorie

      So far so good Matt. The carb cycling I feel has been a big benefit. I’m also a Paleo eater for the most part.

  • Sheila

    Interesting, this is the second time I read about this in the past few days. I’m intrigued by the idea of I.F. but have concerns about going without food and skipping meals. This goes against everything else I’ve read about skipping meals putting your body into “starvation mode” thereby causing your metabolism to slow down. Has the thinking on this changed? How can I be sure that my metabolism will not slow down with the fasting? Any suggestions would be appreciated. Thanks!

    • Coach Calorie

      Sheila, it takes a lot longer than just 16 hours for your body to go into starvation mode. That usually happens from prolonged extreme calorie restriction or fasting for days. As long as you’re eating enough calories every day, your metabolism will be fine.

  • Anne Cunningham

    Hi Coach,
    I’m really interested in this article (actually all your articles) and I would like to give this a shot with an impending holiday in early June and the desire to lose 6lbs (that’s all, not a biggie but I’m finding it impossible). Can I ask a few small questions please:

    Does the fasting have to occur at the same time daily or can it be a moveable feast (pardon the pun)? I have a busy household with 4 boys under 8, evening mealtimes can vary. It’s not a problem for me to fast into the morning if my last meal was 7.30pm. I am trying to encorporate my workouts into pre-breakfast as it is. I do 3 kettlebell sessions a week each lasting over 40 minutes.

    Can you drink water / tea (I’m assuming no)?

    I feel this could suit me as I really enjoy my mealtimes and would rather be hungry and wait than snack inbetween, I’ve pretty much always been a 3 meal a day person as opposed to 6 smaller meals. This is like music to my ears to be honest.

    I’d appreciate any feedback, thank you.

    • Coach Calorie

      Doesn’t have to happen at the same time.

      Water is just fine. Tea is OK too as long as it isn’t filled with sugar.

      Remember that intermittent fasting isn’t fasting in the traditional sense. It’s just getting all your calories in a smaller time frame. You’re still eating just as much and eating healthy.

  • Jennifer Osborne

    Hi Coach,

    Do you do IF everyday or is this meant to be a once or twice a week thing? I’m Catholic and have considered fasting as a spiritual thing but if it will help me lose a few pounds I’d have another reason. But I’m always worried I won’t be able to do it. I think IF will be something I can handle.

    • Coach Calorie

      I do a 16/8 IF every single day. It’s not exact, but for the most part my eating falls within a 6-8 hour window. There are some people that do a 24 hour fast once or twice a week, but I have yet to try that out. The effects of the 16/8 were just fine for me, and it’s not really a fast in the traditional sense.

  • Tom Parker

    I sometimes do a 24 hour fast on a Saturday or a Sunday although I’m nowhere near as consistent as I should be with these 24 hour fasts. Sometimes I’ll do them once a week. Other times I’ll go months without a 24 hour fast.

    My personal experience is that they’re very effective. Not only are they great for fat loss but I also find they really improve your focus. On the days that I do fast, I feel very sharp mentally and normally get a lot more work done.

  • Alison

    Did you measure your body fat% and your muscle% and if so how did they look at the start and the end of a week. I’m noy interested in weight it’s all about reducing body fat for me.

    • Coach Calorie

      I’m glad you understand the importance of weight loss vs fat loss. I did not measure it after a week because I feel the readings are too close together to allow for error. It has been almost 6 weeks now and I’m even more impressed with the results than when I started. Body fat is down and strength is up. Muscle mass is close to the same, but I’m in a calorie deficit and I already carry quite a bit of muscle. I’m going to be doing a follow up post with all the numbers including blood work.

  • Lindsey Pollard

    Honestly, this sounds like a perfect fit for my lifestyle. I have to work FT which equates to about 9 hours a day. Getting home and exercising, fixing a healthy supper, and then cleaning up consumes what little free time I have after work. If all my meals are in by the time I get home, that’s more free time and less stress!!

    Question – if I choose to implement this with the 16/8 time phase, does it matter when I work out? Should it be before or after the consumption, or does it matter?

    Also, do protein shakes count as fasting?

    Thanks for all the great articles. I’ve become a huge fan!


    • Coach Calorie

      It doesn’t matter. Ideally you would exercise before one of your meals, but it’s not mandatory.

      Protein shakes count as food. They need to be eaten during your feeding schedule.

  • dale m

    Hey just found your website and found it a wealth of info ,I am a little confused with this thread what do you mean by Take 10 times your body weight in calories and eat them all within the fasting schedule you decide???

    • Coach Calorie

      Hey Dale, that means to multiply your body weight times 10 )ie 200lbs * 10 = 2000 calories) and eat them all within your fasting schedule. If you eat from noon to 6pm, then all 2000 calories should be consumed within that window.

      • dale mathieson

        Thanks for that simple dumb me ,am going to give a try as lost 77 lbs in 14 months got about 14lbs to go till im happy and just cant get them to move once again great site :)

  • Lindsey Pollard

    Thanks!! I appreciate the feedback :)

  • Keith

    I workout at different times during the day due to my schedule, would it be ok to just try to stick with my first meal always at noon and stop eating by 9pm? Could I just use a post workout shake of 20g whey and some BCAA’s to cover anabolism and recovery until my main meal? Also, could I still use a 15g protein shake pre-workout or would this defeat the entire purpose?

    • Coach Calorie

      I don’t think those protein shakes are going to hurt you, but I also don’t think they are entirely necessary. If a couple hours go by between your workout and your first meal, you’ll be just fine. Concentrate on getting in your calories during your eating window.

  • annie

    I have been following the modified 18/6. I basically do an every-other-day diet to kind of ease into this thing. So for one day I follow the 18/6 and for the next day I’m back to 5 meals per day. Interestingly, the 18/6 stops my cravings which seem to come back when I’m doing the 5 meals per day…and I also stop obsessing about my next meal when doing the 18/6… In terms of weight loss though, I’ve had no change so far after about a week. Since I’m petite and female, over 50, with not much to lose, I’m going to stick it out a while longer.

  • Coach Calorie

    That’s a good idea. One week isn’t near enough time to see results. I wouldn’t have been surprised if you had gained weight from fluctuations in water weight.