Fasting Makes You Active
It’s a familiar image we might attribute to stereotype: a sluggish, maybe portly individual lying prostrate on the couch, his/her front littered with Dorito crumbs. Could there, however, be truth behind the picture? Is there indeed a connection between incessant snacking and chronic slothdom? Or considered another way, is there a connection between fasting and being active? As a long-time fan of intermittent fasting (and a believer in the research behind it), I’m convinced. A study out this month sheds even more light on the relationship between lethargy and continuous eating.
For decades now, conventional wisdom has told us that we should eat regularly throughout the day to keep our blood sugar steady. With three regular meals and at least two snacks, we’re counseled to keep our bodies in a perpetual postprandial state. However, newer research, including this month’s study from ETH Zurich, questions this assumption. Scientists focused on the opposing relationship between a transcription factor, Foxa2, and insulin. Foxa2 is found in both the liver and the hypothalamus, the central command for hunger regulation. It has a hand in the expression of two eating and physical activity related neuropeptides, melanin-concentrating hormone (MCH) and orexin. When insulin is present, as it is during and after eating, Foxa2 and the related MCH and orexin are reduced. However, fasting mice showed consistently high levels of Foxa2, MCH and orexin. The researchers then found that “hyperinsulinemic, obese” mice showed reduced Foxa2, MCH, and orexin, regardless of whether they had eaten or not. When the scientists bred mice with continually active Foxa2 (immune to the counter effect of insulin), these mice showed high levels of MCH and orexin – and a correspondingly high level of physical activity whether they had eaten or not. The specially bred mice had low body fat as well as higher muscle mass.
Consider this study another nail in the coffin of conventional wisdom. (It also goes a long way in explaining the snacking couch potato association.) Fasting, even short, between-meal breaks, promotes the activation of Foxa2 and the resulting formation of MCH and orexin – as well as their activity-inducing effects. A simple survival principle explains this: a hungry animal needs to get up and move to find food. On the other hand, if we are constantly swimming in the insulin of eating and post-eating states, we’re undermining our own motivation (and biochemical stimulus) to get up and burn off what we just ate.
CW encourages us to never skip breakfast, bring along a mid-morning snack, make time for a good lunch, grab a mid-afternoon nibble and then have a good dinner. Oh, and if you can’t sleep, you’re supposed to have warm milk and a banana before bed. Our bodies are either eating or processing what we ate. There’s never a recovery period. Nary a resetting opportunity. We’re so focused on the hobby horse of “stable” blood sugar that we’ve forgotten that there’s more to the biochemical story of balanced energy. We make ourselves feel perpetually full to the exclusion of feeling anything else. (How about light, energized?) We continually raise our blood sugar and insulin levels and, in doing so, turn off the body’s chance to activate or upregulate other key substances that promote energy balance – and as this study shows, the physiological motivation to be active. Simple advice: skip the snack. (Besides, dinner never tasted so good as it does on a healthily empty stomach.)
Let me know your thoughts. IFers – have you found this principle to be apparent in your own experiments? Thanks for reading.
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Posted By: Mark Sisson
Hey Mark, LOVE the site, heard you on CrossFit Radio and have been training my clients (I own a healthclub) using crossfit and paleo (and readings on your site) for some time.
If I may, I’m going to play devils advocate about fasting. I recognize that we’re talking about intermittent fasting but, indulge me.
I’m I’m Grok, and I leave my cave in the morning to go hunt, if I walk past a bush with berries on it, I’m going to grab a handful. If I pass a tree with nuts or apples on it, I’m likely to grab some of those too. All of this as I’m spending my day hunting. That sounds, to me, like numerous small meals a day. Just wanted to add my 2 cents worth.
Hope to hear back from you!
-Hugh MacEachran
Actually Hugh what you described is “undereating” which indeed is a form of Intermediate Fasting… which is fine to do because the amount consumed is and should be far less than the evening meal.
Much of WHAT our Paleolithic ancestors ate is known, but WHEN is only speculated; however can be understood to be more logical to my recommended protocol. Of course one can deduce that they did not water fast every day and when they had a little bit of something they at it.
One way to tell is by studying the cultures who still practice this lifestyle. Indigenous people in South America, Australia, and Africa still eat this same way even today. They don’t have the cancer, diabetes, high blood pressure, and high cholesterol as the Western World does. Of course they have other issues because they’re all inbred, but that’s another article topic altogether for another time.
Bob
Yes Mark I do believe there is wisdom in your post. Though I eat very primal I know my problem is grazing as you and I both call it. Healthy foods but all day = no BF loss. So it’s a New Year and Decade time to go with out in between meals. Should work great at work sense dinner break is at 9:30 pm and I get out at 2am (hey some times Grok had to stay up and guard the camp at night) if I go to bed a little hungry I think that will be a good thing. Let you know how it works out.
You don’t need breakfast or lunch. Once you eat it you’ll engage the Parasympathetic Nervous System which will lower your GH and Testosterone levels and spike insulin. You store fat and get tired.
What If I Can’t Daily Fast?
No problem, but keep in mind that this might simply be an excuse moreover an actuality. In reality you can do whatever you decide to do… as long as you have a plan. Some people believe or strongly feel that they absolutely need to eat during the day. This stems from years and years of doing this due to food being so convenient for us to acquire. I wouldn’t recommend going cold turkey on the water fast protocol unless you are the type of gung ho person who can do that. If that is not you then don’t force yourself to water fast. Eat small pieces of fruit such as berries and fist size fruits. If eating berries is what you want to do then go ahead.
Whenever you eat something- even protein- you get an insulin spike and thus store a little or a lot of fat depending if you have excess blood glucose after breakdown. We want to minimize all insulin spikes by advocating only one primary insulin spike a day and that is in the evening. Therefore you use your body’s fat stores during the day. Instead of spiking insulin when eating you will have your glucagon spiked and thus using stored fat. Then eat when your body actually needs and uses the nutrients for repair and recovery. That is at the end of your day.
There are two environments where the body increases its fat burning hormones and therefore uses its fat stores as fuel. That is while exercising and while fasting. If you can fast for 18-20 hours per day as well as exercise during your fasting period then you will experience amazing results very quickly.
Bob
Since really going full-on paleo, I noticecd that I didn’t need breakfast anymore. I could go until about 1:30 or 2:00 before eating lunch. And I was like buzzing with energy… no slumps. I think it depends a bit on what I ate the day before and how early I had dinner though. If I was carb-heavy then I seemed to get hungry for breakfast. It’s great for travel though. I’m not afraid of my sugar dropping suddenly anymore because it doesn’t.
TrailGrrl
The whole IF topic interests me greatly considering I am a Strength and Conditioning Coach and involved on a daily basis with fat loss clientele. I personally have used IF for about 8mo with fantastic results. After an injury I came down from a stubborn weight of 245 to my more comfortable weight of 225. I also finally managed to get rid of my protruded gut! I’m convinced this was a direct result to the years of following what I was taught to do, eat every 2-3hrs!
What’s interesting to me is that I believe that many “over fat” americans are over-fed and under-nourished. Then there are those others I’ve consulted with that under eat, are “over fat” and are essentially using an IF way of life and not knowing it. Why are these under eaters/non practicing Intermitent Fasters still fat? I honestly believe it’s because of poor macronutrient intake. I believe it all comes down to quality of food and there may be too much emphasis placed on frequency (5-8 small meals) of food.
Now back to the macronutrients issue… Conventional wisdom and the mainstream push low fat dogma. Let’s not forget that the majority of bodybuilders use low fat and this is where Americans originally adopted the concept of eating every 2-3hrs. Why? Because when you eat low fat, you’re always hungry! Eating a low fat diet not only forces you to eat at regular intervals throughout the day it also causes people to crave simple sugars and poor quality carbohydrates. By switching to a Paleo/lower carb type of lifesyle your macronutrient ratio’s switch from a hyper carb (high sugar) to hyper fat (high satiety). This not only elliminates the need for multiple meals it more importantly elliminates sugar cravings, sweet tooths, balances blood sugar and allows people to choose foods of higher quality when they do decide to eat. Let’s also not forget the benifits of better insulin sensitivity, lower risk for ALL degenerative diseases, increased vitality and improved quality of life…
In conclusion it’s probly safe to say that eating less and moving more works after all but… It all DEPENDS on what type macronutrient ratio’s you’re consuming. What’s funny is that you’re really not eating LESS calories, you’re eating LESS frequently! I guess it all just depends. Food for thought.
Is there anyone on this forum that is or has practiced IF and is hypo-glycemic?
I found out about IF from Brad Pilon’s Eat Stop Eat. I started immediately, doing one 24 hour fast on tuesday and one on friday. At that time I was also switching to PB. The first couple of weeks were a real slog, I was so focused on food and where my next meal was comming from, not surprising considering I had been following a 6-8 meal a day body building diet for years. Around about week 3 it got a lot easier and I’ve become more active (in fact I usually now workout only on my fasting days) and each week that goes by it becomes easier and more enjoyable.
Why not make it MUCH simpler!
Ask, act
Ask, act
Am I hungry? No (don’t eat)
Am I hungry? No (but you ate anyway.. ask why?)
Am I hungry? Yes (eat the correct food for YOU)- not for the next Grok.
Forcing ANYTHING is never good.
That’s easy.
I like simpler.
I have been doing IF for over 2 weeks 6 days a week. Eating only in a 4-5 hour window. I feel a lightness to my mind, more focused and on task for my day. I started this after coming off of a 3 day fast of water and tea only. During that fast, I split wood at a cabin, had no issues of needing a nap. I have lost 10 pounds and feel great.
To Matt, Hypoglycemic Question:
I have been myself. Many days waking up at 49 to 70 on the glocometer years ago. After simple carbs it would drop a few hours later. The secret for me is protein, with fat. If I eat them before going to bed, I have normal sugar levels in the morning.
If you are really resistant, you may need more time to get adjusted. My wife is diabetic and is no there yet herself.
This is so cool. I fast typically for three days at a time for religious reasons and I’d always thought it curious that I was never really zapped of all my energy until about the third day. Then I could expend energy but couldn’t recover as quickly. Great Post!
It’s funny how when the word “fast” is mentioned most people immediately go into this brain fog that says “OMG, I’m going to be hungry. Or I’m going to starve until my next meal.” That’s what CW mind control has done to us.
Have you ever been so busy that you didn’t have time to eat or even think about eating? You’ve run around doing this, that or the other and never really feeling starved or hungry.
Guess what – you were fasting. Did you notice how much energy you had while doing all those things? Did you notice how much clearer your thinking was and when your body finally was ready, you noticed, now it’s time to eat.
Of course if you don’t practice PB you might have eaten a little too much or not but the point is you went hours without any harmful side effects.
Until I discovered IF and the science behind it (sorry Mark, Brad Pillon turned me on first), I was eating six meals a day and eating even though I wasn’t hungry because I believed what the “norm” was suppose to be.
Now with PB and IF I am totally liberated and happier. No calorie counting or clock watching and I truly eat food (minus grains) that I love.
I am even switching, I mean suggesting to clients how wrong I was and how the benefits of living a PB life and IF can be more beneficial.
I even started to switch up the regimented workouts for my boot camp. We played kick ball last Saturday (plus I’m still in recovery) and I never saw such a happier bunch of people. Watching them “sprint” around the bases, run down balls and dive for them was just amazing.
Can’t wait to play with them next week.
My first fast was 3 or 4 months ago and it was hard. Headache, feeling shaking, etc. The 2nd one a few days later was so much easier and I have been doing IF once or twice a week now regularly. It has gotten to be so easy. I am so much more in tune with my hunger levels.
I love lifting heavy on the days I IF. I have tons of energy. There may be one hour during the day when my body expects food and I feel kinda “hungry” but it passes soon and I feel amazing the rest of the day.
I seem to have one problem though: I love breaking my fasts with a good beer (like an IPA). I am not trying to lose weight, so I can afford the carbs. And I don’t drink more than one or two, but boy, I just crave a beer at the end of the fast. I don’t drink a beer everyday either, usually just when I fast! Weird?!?
Hi all,
- I have I have been zone paleo for about 1 year solid now,
- I am a moderate gainer,
- My Body fat % is never any more than 8ish and never lower than six.
- I am training pretty hard at the moment and i keep reading more about fasting.
Do you recommend it when training?
If so when should i fast?
I really would appreciate you impute and advice.
Thank you
IF takes a bit to get used to, I got used to it in college when I had work/class 2 days a week solid from 8:00a-5:00p. Since I was so busy I would fast without wanting to, but after a while I stopped getting hungry. Now if I have to skip a meal or eat late it is no biggie. Its a real bonus.
Mark — weren’t you on CW’s side when they recorded the DVDs for Tony Horton’s “P90X?” You were the supplement consultant on that workout/diet program and you recommended that we make sure to eat six small meals a day so our blood sugar doesn’t drop. When did you change your mind?
I knew I’d seen Mark somewhere before! Haha I wonder what Tony Horton would have to say about the PB’s defiance of conventional wisdom? He seems like the kind of guy who’d take a fit if he saw what I ate in a day (or lack of things on an IF lol)
I have been living primally for somewhat less than a year.
Two weeks ago, I rode my bike 40 miles on one cup of coffee and 3 pints of water and did not feel like eating for at least 12 hours afterward with no Ill effects whatsoever and felt wonderful.
I’m a 70 year old male.
I have been living primally for about six weeks now. I do find that I feel satiated for longer periods than ever before, though some days I still get hungry between meals. I’m trying IF (whole day) for the second time, and I find I feel good, plenty of energy, no issues, except I’m really hungry. I know the advice is, if you’re really hungry, eat so you don’t stress yourself. Does this mean I’m not cut out to fast?
Hi, I’m new to IF – going on my 2nd week. I do struggle with hunger occasionaly, but I find when I drink water with a splash of lemon and a dash of cayenne pepper (for kick), I’m good until my window at 5:00. I feel incredible! So in control, and knowing that I am no longer controle by food. This is the longest I’ve stayed on a “diet”. I still have to incorporate better food into my diet, right now I’m eating pretty much what I want, but I know this has to change in order to be at my optimum health, and not to mention my ideal weight. I have about 73 lbs. to loose to be at my desired weight. So far I have lost 6 lbs. and I truly believe this time, with IF, I will reach my goal. So glad to have found this site! If anyone would like to “buddy-up”…I’m all for the support and encouragement!
Now THIS explains why Jack Bauer can go 24 hours without eating! If he DID eat, he wouldn’t be able to go 24 hours at all!
Just started training at Crossfit about a month ago, and trying to get used to this whole Paleo/Primal thing. I fasted for the first time in my life yesterday, went 20(ish) hours, worked all day just drinking water and even golfed after work and felt fine.
ANYWAY.
Here’s my issue: Say for example my in-laws are having us over for dinner and they’re serving lasagna, I’m not going to be one of those a-holes and say, “Nope, sorry, not apart of my diet, won’t eat it…” I’m going to be polite and eat what is being served. Primal is good in theory, but when you’re eating as a family, it really hinders you (or your family).
So what do you do when the family is eating something “non-primal”? Anyone else running into these very real problems?
I can get away with the primal thing for breakfast, no one takes offense if you don’t eat pancakes or waffles.
But when it’s a family meal/dinner, how do you say no?
I came across fasting while working as a weekend security guard. The security handbook manual, specifically mentioned that guards on duty, must not eat or drink anything. Since I was working a full weekend shift…that meant 48 hrs. of a complete abstinence fast. What I found, was that my mind became very clear and alert, and was able to respond to any emergencies quite effectively. Going without food for a few days is a small price to pay, considering the enormous physical and mental benefits resulting from such a dietary practice.
I’d have no problem telling family, hey guys, I trying a new way of eating, please don’t be offended if I don’t have the lasagne. Eat their salad and use the opportunity to tell them how much weight you’ve lost/healthier you feel/etc etc.
If family don’t understand then my gosh you are in a bad way.
If you eat it then suggest an after dinner stroll to deal with SOME of the pasta?
Ive been known to pick out the pasta in a dish and simply say Im sorry I dont eat pasta anymore.
They might surprise you and ask why!
Makes for interesting dinner conversation!
I’ve been trying to read all the posts connected to IFing (love saying IFing–smile). And I have to tell ya, Ifing is amazing for energy for me. I’ve posted earlier, I fast Monday, Tuesday, eat Wednesday, and fast Thursday. Three days of water/week. Tuesday is by far my best day of energy, sleep is incredible on Tuesday night, Wednesday morning I don’t want to ruin by IFing buzz, but I do by noon. I eat pretty normal on Friday through the weekend, you know–beer the whole bit. I have to tell you, I’m really considering going total health nut diet during the weekend, I hate that I ruin my f-ing buzz by eating and drinking– yet, I still am tied to to the sociology of “going out– havin a good time”. It’s just that I’ve never felt this good. Maybe I’ll become a non-drinker…
I began fasting about 3 years ago. I eat once or twice a day although I do take in calories while fasting. These calories are in the form of fats that in my opinion supports the ketogenic aspect of fasting. My diet is strictly low carb which also supports the ketogenic aspects. I am pre-diabetic and I keep my fasting glucose levels under 100. That being said, I can keep my fasting glucose levels under 90 with little effort.Supplements I take are ionic magnesium, vitamin D3, krill oil. If what “they” say is true, regarding the need to eat constantly throughout the day,there would be no way I could eat this way. I plan on going a day or two without eating to increase my fasting window.