Fasting For Health

May 18, 2013    By: Geoff J @ 6:33 pm   Category: Health,Life,Mormon Culture/Practices

A little more than a month ago I came across a BBC program on the subject of fasting. You can watch the whole thing here.

If you don’t have a whole hour to watch I recommend picking up around the 36 minute mark where they start discussing intermittent fasting, or alternate day fasting. The basic concept is to alternate between fasting days and “feasting” days. A fast day consists of 400-500 calories for women or 500-600 calories for men. (You are encouraged to drink all the water you want on fast days). On the feed/feast days you eat whatever you want.

What are purported benefits of alternate day fasting? All sorts of things according to the researchers interviewed. Here are some mentioned in the documentary:

  1. Weight loss. It turns out that people doing this intermittent fasting don’t normally eat double their daily recommended calories on feed days. They are more likely to eat about 110% of recommended caloric intake so there is a net calorie deficit every week and that means steady weight loss.
  2. Reduced blood sugar levels. Warding off diabetes is always a good thing, right?
  3. Reduced levels of triglycerides, bad cholesterol, and blood pressure. They say this is a good thing. Reportedly reduces risk of heart disease and whatnot.
  4. Improved brain function. Mice on intermittent fasting remain mentally sharp far longer than the mice that were fed well daily. The theory is that humans see similar benefits. Fasting reportedly causes brains to grow new brain cells. Researchers interviewed for the piece think that this is an evolutionary survival mechanism; as we fast our brains quickly get stronger to give us better odds of wrangling up some food to stay alive. (I’ve been told that other studies indicate fasting has been shown to improve student test scores as well.)

The host of the BBC show decided to go with a dialed back version of intermittent fasting called the 5:2 diet. On the 5:2 diet he fasts two days per week and feeds on all the other days. After 5-6 weeks he reported losing 14 pounds and reducing his blood sugar and cholesterol levels significantly. (He reduced levels of some other cancer related stuff too — watch the episode for more technical details on that.)

After watching the show I decided to give this 5:2 diet a whack and have been doing it for about 5 weeks now too. So far I like it. First, it isn’t all that hard. As a Mormon, I’m pretty used to fasting already so that wasn’t a big deal. (Although let’s be honest, Mormon fasting often consists of skipping breakfast and then pigging out at “dinner” at 2:00 pm after church.) On this plan drinking all the water I want and downing 600 calories or less on the fast days requires paying attention but it is not that painful. I have been cutting between 1-2 pounds per week on the plan which is cool. What I really like is that I don’t feel guilty when I pig out on occasion during the feed days because I’m still cutting pounds overall on this plan. And if my brain is getting sharper and my risk of cancer, heart disease, and diabetes are dropping as well I could see this as a long term deal for me.

Remember those studies that came out that showed Mormons live longer on average than non-Mormons? The Mormon health code, the Word of Wisdom, is normally credited for those results. I am now wondering if the Mormon habit of fasting at least once per month might be part of the reason for those results as well.

What do you think? We Mormons have a long history of fasting to get closer to God. Do you think there could be merit to this intermittent fasting for health idea too?


  1. I’m doing it as well after seeing the same documentary. However, it is taking some time to adjust my habits to only 500 calories (for a woman) on my fast days. Hope to reap similar benefits. Good luck to you. Do you save your calories for the evening and do a traditional “Mormon” style fast or just eat them as you feel inclined?

    Comment by Another 5:2 Mormon — May 18, 2013 @ 8:38 pm

  2. Nice. You should report back after a while on the program.

    I have a couple of kinds of protein bars around here ranging from 130 to 270 calories. I usually have one of those around noon and another at dinner time on the fast days. In the evening I might add whatever to top off at 600. (On fast Sundays I try to not eat anything to until later in the day but still cap it at 600.) So far it hasn’t seemed all that difficult, which makes me happy.

    Comment by Geoff J — May 18, 2013 @ 9:34 pm

  3. I always think about Jesus going into the “wilderness” and fasting for “40 days and 40 nights.” No one can match what he accomplished in that wilderness, “pain of body, hunger, thirst, and fatigue, even more than man can suffer, except it be unto death;” (Mosiah 3:7)

    Comment by Michael A. Hickman — May 19, 2013 @ 10:20 am

  4. Add me to the list. After 3 weeks I realized I was, on some level, attempting to compensate for the fast days by overeating on feed days. I’ve since stopped that by instituting some calorie control measures on feed days too. Now, things seem to be rolling along and it does not seem troublesome. I feel somewhat better and I’ll be interested to see long term effects. I plan to continue for 6 months with careful monitoring. Let’s face it. What I’m really looking for are Wolverine abs.

    Comment by wvs — May 19, 2013 @ 4:11 pm

  5. wvs,

    I know that intermittent fasting has taken on a small following in the world of bodybuilding. So, there are definitely some likeminded folk out there.

    Comment by DavidF — May 19, 2013 @ 7:36 pm

  6. Wolverine abs for all!

    Comment by Geoff J — May 19, 2013 @ 8:18 pm

  7. Absolutely fascinating. Thanks for passing that along. For a long time the conventional wisdom was to eat 5-6 small meals throughout the day in order to keep your metabolism humming along. But when I tried this I would inevitably fall off the wagon because the small meals never satisfied me. And recent research has proved that metabolism goes up the same amount whether you eat 5-6 small meals or 2-3 big ones anyways.

    I hadn’t heard of the 5:2 diet or alternate day fasting, but this year I have been doing a different kind of intermittent fasting which has become very popular in the fitness world during the past few years, where you restrict your daily calorie intake to an 8-hour or so period. On my own I decided to find a reason to fast every Sunday in addition to this. So far I have lost 35 lbs since Jan 1. I have also been feeling sharper mentally which I assumed was from eating better food but now I’m thinking it is due to the weekly fasting! I am definitely going to try this 5/2 thing from now on!

    Comment by Bryan H. — May 19, 2013 @ 10:23 pm

  8. Those are impressive results, Bryan H. I hope you report back here how shifting to a 5:2 helped or not.

    Comment by Geoff J — May 20, 2013 @ 8:44 am

  9. Curious. I might give this a try.

    Comment by Adam G. — May 22, 2013 @ 1:03 pm

  10. My father who passed away in 2000AD spent the last years of his life as a “medical weight management” specialist. He was an M.D. who was an anesthesiologist for most of his career. His primary approach to weight control was fasting. He fasted a lot and as a result I was encouraged to fast. He cited the work of Roy Walford


    who did much of the original research on the role that fasting plays in longevity. Walford was an gerontologist with an international reputation and the head of the UCLA Longevity Research Labs or something like that.

    I experimented with fasting during the 1980’s and 1990’s. I fasted with only water for 6.5 days, 10 days, and 14 days. I tried to fast for 30 days but had to stop because I started to feel like it was making me sick.

    Since then I have learned that a strict avoidance of carbohydrates does me as much good as fasting in losing weight. I have lost over a hundred pounds and kept the weight off for a substantial period of time.

    But I highly recommend water fasts for those who can do it. Every time I have done it, I have felt much healthier afterwards. I think there are balances in our bodies unique to ourselves that get out of balance over time from the things we eat. Fasting restores those balances. Or so I surmise. It isn’t very scientific, although there is a lot in the medical literature on fasting. Most folks have no idea how long we can go without eating with no ill effects.

    Comment by John W. Redelfs — May 30, 2013 @ 11:41 am

  11. Water only fasts for 24 hours or more are a little hardcore for me. That’s what I like about these modified fasts with 500-600 calories. Supposed to have most of the benefits but not as hardcore as some of the other options.

    Comment by Geoff J — May 30, 2013 @ 2:52 pm

  12. I wonder how much of the research has been done with women? I think there are many ways to lose weight, but I would never try anything that you couldn’t do while doing strength training (weights) three times a week. Women as young as their 30s tend to lose muscle when dieting, which is long-term counterproductive and unhealthy.

    I’m also one of those who does better with low carb than fasting. I might have white potatoes or white rice once a month, but they have a bad effect on me.

    Comment by Naismith — May 31, 2013 @ 10:41 am

  13. Naismith,

    The documentary implied that the intermittent fasting studies applied to men and women equally. And there is nothing about reducing caloric intake a few times per week that would interfere with weight training. I’ve been hitting the weights throughout my time trying this 5:2 thing and it is no biggie at all. But I very much agree with your point about doing what works for you.

    Comment by Geoff J — May 31, 2013 @ 11:08 am

  14. I am glad that you found something that works for you. The more options out there, the better for everyone. But I read some of the published studies, and they seemed to have more dropouts from the intermittent diet then the other options in the trials. So while the findings are positive for those who can stick with it, not everyone can adhere. There’s a certain amount of self-selection going on.

    For me, I could not live my life (10 mile a day bike commute) or have the energy to go to the gym if I was fasting. I even travel to church in a car if I can on fast Sundays. And the fruit that guy in the video eats every morning would make me even more hypoglycemic by 10 a.m. than fasting. So yeah, we are all different.

    Comment by Naismith — June 1, 2013 @ 10:28 am

  15. Update — So I was on the 5:2 fasting diet for a couple of months. I lost about about 8 lbs and felt good. After a while the weight loss pretty much tapered off so I assume I got to some plateau but I’m not overweight so that was fine.

    Then vacation season started and I got off it all a few weeks ago. I put a few pounds back on so I’m getting back on the train again now.

    Comment by Geoff J — July 19, 2013 @ 2:22 pm