Thoughts on fasting
Last week, someone was preaching to me about the benefits of fasting. This particular person fasts for health and religious reasons, and told me they do it 2-3 (consecutive) days a week.
Of course, I was skeptical, especially after the person cited references to fasting testing done on worms. Sure, worms may live longer if they fast, but how long do they live anyway? And aren’t our digestive systems just a teeny bit different?!
The person preaching to me couldn’t give me any answers (of course), so I did a bit of research with my good buddy wikipedia, and am here to ask you your thoughts. Note, this is just about fasting for health reasons, not religious reasons.
What is fasting?
Fasting is the act of abstaining from all food and drink for a period of time. There are different types of fasts – certain ones allow water, raw food, or a very limited calorie intake. I am discussing a fast where you only drink water for a day or more.
What happens to your body when you fast?
Glucose is the body’s primary fuel source. When you fast for 4-8 hours, your body converts glycogen from your liver into glucose to use for fuel. Your body also uses protein to supplement the glycogen. This fuel will last for up to 12 hours, then your body will turn to muscle for glycogen. If glycogen is unavailable, the body will turn to fat as a fuel source. The body will continue to use fat until it is unavailable, at which point the body will switch to using protein for fuel, and will be in a state of starvation (fasts are normally broken before this point).
What are the benefits of fasting?
According to Dr. Mark P. Mattson*, fasting every other day (known as Intermittent Fasting) shows beneficial effects as strong as those in caloric-restriction diets (I would hope so…).
Other possible benefits:
- increased life span
- reduced risk of cancer, Alzheimer’s, cardiovascular diseases, diabetes, insulin resistance, and immune disorders
- stress resistance
- increased insulin sensitivity
- reduced morbidity
- detoxification – there is no evidence supporting this, and our bodies are naturally designed to remove toxins through our skin (sweating) and liver, colon and kidneys, but this is what the person was preaching to me
What are the dangers of fasting?
Intermittent fasting (eating every other day, typically) causes lowered blood sugar and blood pressure, which can lead to dizziness and blackouts. Oh yeah, and it makes you possibly feel weaker and CRANKY.
As you fast, your body lowers its metabolism to conserve energy; when you go back to your normal diet, your lowered metabolism may cause you to store more energy – a possibility of gaining weight.
If you fast for too long, your body will lack a variety of vitamins, minerals and nutrients, which can lead to symptoms such as fatigue, dizziness, constipation, dehydration, gallstones, and cold intolerance. Fasting for too long also causes your body to go into a starvation mode. From wikipedia: “Medical complications associated with fast-induced starvation include electrolyte imbalances, thinning hair, lanugo, cardiac arrhythmia and renal failure.” Also, what distinguishes fasting from essentially starving yourself? Is there a risk of it getting out of control?
Will I try fasting?
Probably not. As I told the person who was preaching this to me – I eat every 3-4 hours now, or I get a headache and feel unwell. They assured me that I could build up to fasting – similar to how I told them they could build up to running, slowly. But, I just don’t think this is something I need to get in to. As someone who prefers to participate in endurance activities and exercise regularly, I prefer to be “fueled.” (Although some say it is fine to exercise when fasting… not sure that is for me).
Sometimes, I do a lighter diet for a day, sort of a “detox” to get myself back on track. I guess that is the closest I will get to fasting.
What do you think about fasting? Have you ever tried it? Do you think it could be beneficial? Do you think it’s a load of crap?
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Side Note #2: If you voted yes to read my Training Week 17 poo story (18 out of 21 did!), it has been updated here.
*Chief of the laboratory of neurosciences at the National Institute on Aging
Themocracy
I’ve had a friend or two who have fasted for various reasons, but it has never appealed to me. Like you, I like to feel fueled throughout my day…plus I just really like food!! 🙂
My dh talks alot about fasting/calorie restriction. I can see where it could be a good thing in that you’re giving your body a ‘break’ from the metabolic process. But I’m talking about maybe skipping a meal, not a whole day of nutrition and water.
Overall I think it’s fairly apparent, most of us eat too much, but IMO fasting is not the answer.
Aside from fasting for religious reasons which I would understand and support based on that person’s principals, I really don’t condone it for the health benefits. Since our bodies have no storage form for protein other then muscle protein, even short-duration fasting (1/2 a day or more) leads to losing important body proteins (from the liver, digestive tract, etc.) Not good!
Such an interesting and great question! 😀
I would crash hard and pass out if food is with held from me. And when I woke back up that person better run because I would be cranky AND hungry which puts me in the “dangerous to others” category. 😀
LOL. We are too similar 😉
Oh, you’re not on the Worm Diet? I am! I eat only food that worms eat, and I exercise like a worm! Time for my morning wriggle!
Seriously, I agree with you. I know “cleanses” are big right now but if you are not smoking and eating crap, I’m not sure what your body has to get rid of. I could see eating light one day and trying to detox a little, but not going without food for the whole day.
You totally cracked me up with your “wriggle” comment.
I am not sure why this person thought I needed to detox so much. I think they are, buh buh bum… CRAZY!!!
I don’t think I could fast without pretty much being dormant for a day. I know a lot of people who do this pretty regularly (like 1 a month) but it just isn’t for me.
hmmmmmmmm!!!!!!!!!!!! interesting topic! you always have something new for me to think about 🙂 i would be interested in trying a fast as part of a group effort, maybe, just so i could have people to talk to about it. i think trying to impose meaning on yourself (aka religious) and fasting and expecting too much from it can be dangerous. it is a completely different animal if you grow up in a family who does fasts as part of a cultural/religious group… but just deciding to do it, esp for weight loss reasons… i’m so not a believer.
i think what i would want out of it is to satisfy my curiosity about it. i would forewarn anyone that i would be CRANKY and i don’t knwo what i would do with myself. i spend a lot of time eating… hehe. i guess at a meal time i would have to do something like yoga or meditate or go for a walk. i woudl def need support.
The group idea is interesting. I think there are groups who did it together. And I think they do meditate or do yoga during meal time. Ugh. You are brave to want to try it!
Personally, I’m not interested in the idea of fasting…but, I know that there are these place one can go and fast for days at a time (usually done once or twice a year). Those who go swear it makes them healthier. I say, great…but no thanks (at least for now). I’ve learnt to never say never 🙂
Hmm, kind of like a spa or retreat for fasting? I guess it would be better to do it in a controlled environment!
Food is WAY too much a part of my daily life- additionally, I am hypoglycemic so it could really hurt me- so no, I don’t ever see myself as a faster!
I fast 30 days during Ramadan. Let me tell you, it is the hardest thing in the world! Especially now that it is during the hot months of August. I don’t think it is very healthy, especially since I have low blood pressure, but I do it for religious reasons. And afterwards I feel so accomplished. But during the 30 days? I am in a terrible mood, unfortunately!
Do you eat during the night? Is that how Ramadan works? I apologize for my ignorance. I am sorry it is so horrible for you!
I have never fasted before I usually do a week long cleanse once a year where if I exercise its just a walk (usually a walk to my classes) and I’ll eat strictly veggies and fruit but I have never fasted.
I think your version of the cleanse sounds much better 🙂
I think I’m such a bad Jew because I just can’t fathom fasting (and there’s a holiday or two in there where you’re supposed to fast for 24 hours). ha.
In all seriousness, my guess is the negatives far outweigh the possible positives, so I doubt I’ll be fasting anytime soon, either. Hey, let’s NOT fast together! =)
As always, very nice research on an interesting topic. I think you’re spot on about fasting for health. The ramifications of the sways in metabolism seem too large.
Fasting for religious reasons I think are a little different, as ‘religion’ can seemingly be used to justify anything.
How I would love to write a post (or series) entirely devoted to your last paragraph…
Other than for religious regions, I couldn’t fast on a regular basis. I can’t see how fasting would do my body any good.
Yikes, no thanks. I just can’t do it. I am an angry angry beast when I don’t eat. 😉
I’ve never done a fast simply because I could never be strict enough. Plus I like chewing! 😉 I though about doing one though but I think that’s just not that great for me. It might work for other people though.
I don’t fast. I figure if I eat “clean” most of the time, drink lots of water and exercise I’m in pretty good shape. I’m already on the thin side and I think fasting would probably not be the healthiest choice for my body.
I could never fast during the day – I also have to eat at regular intervals or I feel sick. However, I usually treat my body to a “mini fast” nearly every day by not eating after dinner (and we eat fairly early – about 6) – I used to be a big evening snacker and this was a habit that was hard to kick but made me feel so much better once I got it down. I feel so much better in the mornings now!!!
You know, when I don’t eat after dinner, I sleep better and feel better too. There must actually be something to that 😉
I agree that the dangers far outweigh the benefits. I don’t ever plan to try this on purpose. I’ve seen already what happens if I go too long without eating (headache, light headedness, tunnel vision, crankiness) and don’t want to see it magnified.
I know you said this post is referring to fasting for health reasons, as opposed to religious reasons; but knowing what I know from fasting for religious reasons, fasting for HEALTH reasons is ludicrous. For me, anyway. It surprises most people to hear this, but I actually dislike fasting very much — because then I have to break it. Fasting every other day is just an unnecessary headache.
But, like they say… “different strokes for different folks.” Definitely not for me.
<3 <3
I think fasting- as in not eating or drinking any calories- is a load of crap (to put it bluntly) lol. Even if it may increase your lifespan for a couple years…it must be aweful to feel hungry all the time. My friend is doing the stupid lemon/cayenne diet and…well I’ll just save my rant for a post 😉
I want to read that rant now!
I like your point – would you rather live longer if it means feeling crappy about 40% of the time?! NO!
Its crazy how some people in wealthy countries like ours VOLUNTARILY starve themselves! I mean, c’mon! We have access to all this wonderful food, while there are other people in the world who don’t even have access to drinkable water!
Such a good point. I should point that out that each year for the holidays, this person sends money in our names to starving families.
i know a lot of people who really enjoy fasting as a way to “cleanse,” but… oof, not for me!! i pass out when my blood sugar drops, and let’s not even TALK about how cranky i get before that! 🙂
Like you, I don’t feel well if I don’t eat regularly.I actually turn into a bear if I let myself get more than a little hungry so for my family’s sake, I don’t think I’ll ever try it.
Hm, fasting does not appeal to me at all. I know that sounds funny coming from someone who struggled with anorexia, but even in the worst of my illness, I never fasted. I just restricted heavily. I didn’t skip meals; I just cut them down to a few hundred calories. I really can’t imagine going a whole day without food. I can’t believe this person does it 2-3 times per week! I really enjoy eating and I like to eat every few hours. If there are benefits to fasting, I don’t really care to explore them 😉
Thanks for sharing your story. I was wondering what input you would have and hoped that this post wouldn’t upset you! 🙂
No fasting for me since it encourages my binges. From not on I am really trying to focus on restricting as little as possible. I’ve tried fasting many times in the past and they were always a big fat fail!
Yeah… it encourages me to binge too. As does restriction.
Yeah.. no fasting for me, I enjoy eating way too much. I’m skeptical. And I don’t really see the point. I completely agree with your concern about it getting out of control and I don’t see how this is much worse than an eating disorder..
i am extremely opposed to fasting. i understand that some people truly do it for religious reasons, so i put that in a different category, but for any other purpose i think it’s a load of crap. i know i’m biased, “fasting” is just a synonym for anorexia in my personal experience, but it’s simply not healthy for the body. short term results may seem promising but over time your body starts to fear that it will be deprived of food and will begin storing as much as it can to get through those times of starvation. who the hell wants to be dizzy and hungry anyway? it also leads to binging afterward, sort of defeating the purpose right? thanks for letting me know about the spam problem, i got you outta there!
Thanks for rescuing me from spam! 😛
I feel the same way as you about the fasting. I just can’t imagine why so many people choose to do it.
I don’t think I’d ever be into the whole fasting thing. I just don’t see how someone can stay healthy while doing it. The whole “lowing your metabolism” thing is a major turn off for me when it comes to fasting. Also, I don’t see where exercising would be able to fit into the situation. Just skip exercising everyday that you’re fasting or something? Also, a completely no water, no food, no anything, diet sounds extremely dangerous. I would imagine you have to stay completely immobile all day in order to not completely mess yourself up.
I figured you would skip exercise too, but some people actually say you can still exercise. No thanks!
Great topic Kim! (not a surprise though, I haven’t read anything here that I don’t like)
I am completely against fasting. I don’t think it is very smart and healthy for the body. I would never consider fasting…. in my opinion a cleanse/detox which eliminates certain foods is much more effective and beneficial than not eating at all.
Like Ameena mentioned above, I used to fast during the 30 days of Ramadan, I don’t anymore because of my digestive problems, but even when I think about my mom fasting and then eating 3 meals worth at dinner time right before she goes to bed I think it is definately not healthy.
PS. A while back we had talked about meal planning… my post tonight is about meal planning.. I thought you might find it intresting.
Thank you 🙂
So you eat THREE meals at night? Or the equivalent of three meals? Wow! I would not be able to sleep.
I loved your meal planning post!
not too keen on the fasting thing. HMMM. i get REAL angry when i’m hungry. and i dislike the weird lightheaded feeling.
GLAD YOU LIKE THE DOMOS! (domo is the monster’s name!)
Interesting. I didn’t know fasting could have any health benefits. Learn something new everyday.
I know a lot of people that do it for religious reasons, but I’ve never tried it.
haha I had to laugh that the testing was done on worms. Why would anyone think to test anything on worms anyhow?
I have tried fasting a few times, but that was for entirely unhealthy reasons. It was a way to feed my eating disorder and try to call it something “healthy” and “detoxing”. Im completely against it now.
back in my eating disorder days i fasted a lot. it’s called anorexia. don’t do that anymore, no siree!!!
That is kind of what I was thinking when I was researching this… how far away is this from anorexia?
When I was in high school, fasting was the way to diet. Or there was the eat only grapefruit for a week diet. Like that was going to keep the weight off!
Older and wiser now, I really don’t believe fasting does anything for the body since it is such a short term regime. I believe the body, like a machine, needs a constant supply of fuel to stay in good working order. I do believe a “leaner” life is healther for our bodies than a “heavier” one.
Occasionally I have to fast because of a doctors apt or a medication or something. One of those, no eating (sometimes no water) after a certain time at night until a certain time in the morning. Its the hardest 12 hours ever. Thats about the extent of fasting I will ever do 🙂
I’ve thought about fasting but to be honest, I don’t really think it’s that beneficial. Your body is constantly cleansing and detoxifying itself whether you abstain from eating or not. About a month ago I did a 24 hour fast but that’s about it. It actually wasn’t that bad but I still didn’t feel as if I benefited from it. If you stick to a diet that mainly consists of wholesome foods – raw fruits and veggies, whole grains, etc. – then you really shouldn’t need to fast.
Agreed – stay as healthy as you can… and when you eating something crappy, let your body take care of it! (The key is to not do it that often! 😉 )
Glad to “meet” another 10/10/10 runner! I, too, am super excited and terrified…maybe that fear will ease up after I’ve done my half marathon in May. 🙂
And as for fasting–never! I’m hypoglycemic and would probably go into a low blood sugar-induced coma. 🙂
I used to fast once a week in high school (for religious reasons). I actually grew to enjoy it just in a sense of realizing that food wasn’t quite as essential as I had thought it was (I love food now, but I looooved food then and you could tell ;)). I don’t think I would be comfortable fasting regularly now though; I get really hungry after running or working out and think my normally pleasant disposition would go waaaay down if I didn’t eat!
I am fasting today, actually! (Ash Wednesday). Buuuuut – I guess Catholics fast a little differently. I’ve always understood it to be a small breakfast/lunch (combined to make one normal meal size), and a normal dinner – no snacking at all. It’s not too hard. I could NEVER do just water all day! I mean, I could, but seriously no one would want to be around me.
I do not fast, unless I have some medical procedure I’m getting. But years ago, I used to (for religious reasons) and it seemed to help my body readjust itself.
Today, I’ve scaled back my portions to a more reasonable size and that has helped my body adjust to less food. For me, going without food for more than 4 hours (unless I’m sleeping) is not good for my stomach or my attitude (i get cranky and irritable).
I like your approach – smaller meals, more often. That is what I try to do too. Steven and I have a theory that if we eat smaller meals, we will have smaller stomachs that hold less, so although we may feel hungry more often, we are likely to eat less. Yeah. We’re crazy.
I have kept this post on my feed reader for a couple of weeks because I really wanted to explore it a second time. Very good stuff. I love all of the comments too.
Fasting 2-3 days a week sounds crazy to me but I would imagine it’s probably not too bad if this person staggers the fasting days with eating days. If they do it every weekend or something, that’s nuts.
Still, most Americans eat way too much. Centenarians have several things in common — restricted diet, low stress, active body, active mind. It all sounds so simple.
I fasted for three days when I was a teenager. I did an all-liquid diet (including Slim-Fast) for about a week. Both times, I felt so good after about 24-48 hours. It’s weird. After you stop feeling hunger you still have to battle feeling tired.
I doubt I’ll ever do more than a 24-hour cleanse but I could see where that would be beneficial for someone who eats a lot of crap. [Avoids eye contact with mirror.]
I’m fat enough now I might be able to qualify for lap-band or gastric bypass surgery. I’m still thinking about it but I don’t know. I’ve been really impressed by Adam Avitable’s weight-loss.
Either way, it’s going to be hard work to get this weight off but I have to do something. I’m getting too old to keep gaining weight.
I’m sorry it took me so long to respond to this! I do agree that many of us eat too much, and fasting would help flush a lot of crap out of our systems… but what would keep us from eating it again when we were done with the fast (I have to avoid eye contact with the mirror on this one too).
I haven’t been following Adam’s weight-loss. What has he been doing? Just eating healthier and exercising? Or did he get lap-band? What is causing you to gain weight? Is it stress eating? I know that is what does it for me 🙁