I don’t think I’ll ever forget the incredible experience I put myself through beginning on the evening of April 10th through Sunday, April 17, 2011 when I consciously chose to do one of the most unlikely things for the first time ever in nearly four decades of living–I embarked on a one-week fast–ON PURPOSE–just to see how I would do. This isn’t something I just flippantly decided to try on a whim, though. I had asked my readers in this February 2011 blog post if they had ever tried an extended fasting period like this before and so many of them responded with their feedback about how it went for them–good, bad and ugly. In fact, one sweet Christian lady named Wendy blogged daily about her own 40-day fast after her pastor challenged their congregation at the beginning of the year to do it for spiritual renewal. So many other people I talked to about fasting shared with me how amazing they felt both during and after fasting that I concluded this was something I wanted to try for myself.

This personal interest in doing a one-week fast actually started ruminating in my mind way back in November 2009 when I interviewed a Boston College brain cancer researcher named Dr. Thomas Seyfried (listen to him share about how doing an annual 7-10 day water fast can be used as a therapeutic means for preventing cancer starting at around 27:48 in the interview). At the time I thought the idea of going without food for a couple of days, much less a week, was virtually impossible (and crazy!) for me. I was already dealing with some reactive hypoglycemia that saw my blood sugars dropping out of the blue even eating low-carb foods. However, this seemed to normalize itself last year when I went on my “eggfest.” So with my concerns about my blood sugar causing me issues beginning a genuine attempt at a weeklong fast, the only question was when to do it. After attending the low-carb science conference in Baltimore the weekend prior to this and knowing the 4th Annual Low-Carb Cruise wasn’t coming up for a few more weeks, I decided this was the perfect time to give it a go. And so I decided to do it in earnest.

I’ll admit that I went into this extremely skeptical whether I’d be able to last very long. It’s not that I didn’t have confidence in myself that I could do it, but it just seemed too implausible for a food lover like me to lay down the fork for an entire week. My expectations for attempting this were wide open and I simply wanted to go through the experience just to see what it would be like. So many people asked if I was doing this to lose weight and the emphatic answer is not at all. Any weight loss on a complete fast would not likely stay off once food is reintroduced to the body. That’s not to say a few stubborn pounds of fat wouldn’t find a way to leave my body and that’s never a bad thing. But my primary purpose was to monitor how I felt going without any food for a week. Here’s my 7 daily update videos about how each day of my fast went:

http://www.youtube.com/view_play_list?p=A00A6F99D882F892

I learned so much more than I could have ever bargained for in a variety of ways:

PHYSICALLY DOING THE FAST
The first three days for me were some of the most difficult because my body was screaming at me to eat something. I felt “spacey” for much of the time as if everything around me was running in slow motion. At the same time, my thoughts were clear and I was fully functioning despite having no food. And honestly, I felt good for most of the time through this fast. Days 4 and 5 were the BEST of the seven as I experienced the big “whoosh” of renewed energy that I had heard so many people share would happen. Day 6, though, I struggled early on with a strong desire to eat again and by Day 7 when I was at church I felt absolutely horrible feeling like my blood sugar had dropped to a level that zapped me of all my energy. When I saw a reading in the 50s and could barely stand up around 2PM on the final day of the fast, I knew it was time to break it.

BLOOD SUGAR AND WEIGHT
I didn’t measure my blood sugar every single day, but the few times I did show readings like the one you see above in the 60s. Sure, this is below the around 80 fasting blood sugars I generally see on my healthy low-carb lifestyle, but that’s what happens when you don’t eat any food at all. Controlling blood sugar and giving your pancreas a week to rest from producing insulin (if you aren’t a diabetic) is an excellent reason for attempting a fast like this. My weight on the other hand was monitored each day starting at around 261 when this began. The first few days saw about a pound a day come off and then Days 4-7 saw a couple to several pounds drop. While I wasn’t doing this to lose weight, it certainly produced a sizable drop on the scale of 13 pounds in one week. I fully expect to put some of that weight back on this week as I return to eating again.

EXERCISE DURING THE FAST
Believe it or not, I decided to keep up with my exercise routine during my fasting week and I did a whole lot better than I thought. I knew not to push it too hard and if I told my wife Christine if I started to feel dizzy or anything that I would stop. Even still, I played competitive volleyball TWICE and did a couple of Pilates/yoga classes with no problems to be concerned with. Although I was “spacey” on the volleyball court, I was able to perform quite well running, jumping, and blocking spikes on the front row! BRING IT!

BATHROOM RESPONSE TO THE FAST
Yes, I know it’s gross to talk about, but it was a part of the fasting experience. I expected to visit the porcelain goddess frequently in the first couple of days or so, but when I was still seeing massive amounts of “stuff” coming out late in the week during the fast, that was pretty freaky. It reminded me that there’s a lot more waste in the body than we even realize and doing this fast may have helped clean a good bit of that out.

SUPPLEMENTATION DURING THE FAST
I did not stop taking my regular supplements for the duration of the fast. I continued on with my multivitamin, Vitamin D3, magnesium, probiotics and other array of vitamins that have been a part of my healthy low-carb lifestyle for years. Perhaps I could have given this routine a rest for a week, too, but I didn’t.

MY METHODS FOR ENDURING THE FAST
This was my first attempt at fasting for longer than a day ever, so I didn’t have any idea what to expect beyond what I had heard from others. One of the challenges I found was how to ward off the symptoms of not eating anything. I was guzzling a lot of water throughout (very important for anyone fasting), but I decided I wanted more. So I added in some diet sodas again to help get me through. While I realize consuming diet soft drinks is controversial to some people who think you shouldn’t ever consume this stuff, it’s what I chose to do during my fast. Right or wrong, it’s what I did and I believe it helped me get through it. To me, it was most important to make it to the end of the seven days with non-caloric liquids throughout. I also used chicken bouillon cube broth after a few days on the fast as recommended by a dozen low-carb researchers and practitioners for electrolyte balance. It most definitely helped me feel revived and renewed when my energy started to wane. While I didn’t do this fast primarily for spiritual purposes, it certainly helped remind me to focus on the vital role God plays in my life on a daily basis.

THE REACTION FROM PEOPLE ABOUT MY FAST
When I started sharing my fasting experience and what I was doing on my menus blog, at Facebook and Twitter, on YouTube and elsewhere, the reaction I received was probably the most surprising part of this entire process. It ran all across the spectrum from encouraging words from people who thought this was a great idea and cheered me on all the way to people telling me I was killing myself and undermining the very low-carb lifestyle principles I promote. Wanna see just a small taste of what I’m talking about? Check out my favorite quotes both positive and negative from the fasting week:

And it seems I’ve inspired another low-carb blogger named Steve Cooksey to try a one-week fast, too:

GO GET ‘EM STEVE! It’s interesting to see how quickly his fasting blood sugar numbers have fallen.

WHAT WOULD I HAVE DONE DIFFERENTLY?
I hate to say I’d change anything about this first experience trying a one-week fast. The experience was what it was with all that I did. If I had it to do all over again (and perhaps I’ll try this again sometime), I’d go in one direction or another. Either a full-out water only fast or a coconut oil-based fast for some nourishment. I had on my protocol of things to do for this fast to add in coconut oil if the hunger became too much to bear. It never did, but I can’t help but think if the addition of coconut oil to the mix might have made a difference in the way I felt. It might have stoked some hunger, but maybe not. I guess that means I’ll need to try it again sometime and do it that way just to find out.

After the fast ended, I decided to write to the man who inspired this one-week fast–Dr. Seyfried himself–who I met in person at the Baltimore Nutrition & Metabolism Society Symposium the weekend before I started. When I told him what I had done, he said he was happy to hear I “survived” my fasting experience. Noting my concern about feeling bad on the final day of the fast, Dr. Seyfried said this “surprised” him because “most people who do the water-only fast feel good on Day 7″ and that blood glucose levels in the 50s are “good and should not make you feel bad.” He said the vitamins I took and bouillon may have sent “mixed signals to the body” which made it more difficult.

Dr. Seyfried noted that a cancer-preventing fast should probably be done using distilled water only and nothing else:

A therapeutic fast should not contain any nutrients. The body will release vitamins from fat and minerals from bones during the fast.

He explained that the weight loss on a one-week fast like this is mostly water weight because the fasting process depletes glycogen stores which retain most of the water in the body. Dr. Seyfried noted that there is some “minor” protein loss “especially if fat is mobilized” and he lamented that I didn’t measure blood ketone levels with a ketone meter like Medisense Xtra. He explains this is better than measuring ketones in the urine using Ketostix as is popular among low-carb dieters.

If your blood ketone levels are elevated then you are definitely burning fat.

I’ll be sure to do that the next time I do an extended fast. When I asked what this weeklong fasting does to cancer cells, he said the “damage to mitochondrial respiration is the origin of all cancers.”

Fasting will induce cellular autophagy thus allowing the cells of the body to consume damaged or defective mitochondria. Metabolism of ketone bodies will reduce damaging oxygen radicals while enhancing the metabolic efficiency of the mitochondria. Fasting prevents cancer by enhancing the metabolic efficiency of mitochondria and by eliminating damaged mitochondria.

With the diarrhea I experienced midway through my fast, Dr. Seyfried said this is “not expected” because it’s a way the body is cleansing itself of toxins. He recommended a book Herbert M. Shelton called Fasting for Renewal of Life that gets into the nitty gritty of what is happening when you fast. I’ll be sure to read this book before beginning my next fast. He reiterated the importance of consuming only distilled water or a small amount of non-caffeinated green tea. As for the vitamins I took during my fast, he said they are “not needed for short fasts (less than 20 days).” If a 20-day fast is short, then remind me not to try a long one!

He didn’t have an issue with me exercising during my fast “as long as it is not too extreme.”

I think walking is fine, but I am not sure about Pilates, volleyball or other types of vigorous exercise. Fasting is a time for rejuvenation and relaxation. Excessive exercise will prevent this and potentially harm the body. This might have accounted for some of your tiredness.

That’s a good point. Perhaps laying off the exercise just for the week of the fast would have been a better idea that trying to keep my regular routine up. I’ll remember that for the next time I attempt to do this. All in all, it was quite the education going through my first-ever one-week fasting experiment and I feel fantastic just a few days afterwards since I reintroduced food into my diet. I’m back to engaging in daily intermittent fasting of about 19 hours a day which doesn’t sound so daunting anymore after going a week without eating! I’d love to know what you think about this idea of fasting for a week, whether you think it helps or harms in the long run, and if you have or would ever try this for yourself. Leave your comments below! I expect a wide array of ideas and opinions and all are welcome here.

Jimmy Moore is the popular blogger, podcaster and author of Livin’ La Vida Low-Carb who lost 180 pounds on the Atkins diet in 2004 and quickly established himself as a highly influential layperson in the field of health and nutrition. His wildly successful Livin’ La Vida Low-Carb Blog has been educating, encouraging and inspiring readers since 2005 and his accompanying iTunes podcast The Livin’ La Vida Low-Carb Show with Jimmy Moore is one of the most listened to health broadcasts online today featuring hundreds of enchanting interviews with the leading voices in the world of diet and healthy living! Jimmy’s latest book compiling all the knowledge he has learned along his journey is called 21 Life Lessons From Livin’ La Vida Low-Carb: How The Health Low-Carb Lifestyle Changed Everything I Thought I Knew. He lives in Spartanburg, SC with his beautiful wife Christine and their four crazy cats!