Sunday, February 17, 2013

I Fasted For 7 Days

From Feb 2nd to Feb 8th, I ate no food at all, consuming only water. I am not a doctor; none of this is medical advice. But people have asked me about it, so I'm going to explain a little.

Geeks will have an easier time understanding fasting than regular people.

Garbage Collection

I got most of my information from a book by Dr. Joel Fuhrman, a doctor who's guided very large numbers of different patients through fasts. The book explains that fasting longer than 3 or 4 days triggers a protein-sparing process, which geeks can understand as a garbage collector.

During the first few days of a fast, the body will burn muscle for glucose, causing muscle loss, but after those few days, the metabolism switches to a different method of generating energy, and although this process also uses cells from the body as fuel, the garbage collector prioritizes which cells.

The garbage collector first burns fat. I lost at least 20 pounds during the week I fasted. After it finishes burning the available reserves of fat, it then progresses to various types of useless cells. As an example of useless cells, some fasters have literally seen warts and moles disappear, or even simply fall off their bodies. But there's a much more dangerous type of useless cell which the body will recycle first.

I have coronary artery disease, which means I have a large number of cholesterol lesions in my arteries. Cholesterol lesions consist both of actual cholesterol, and of cells which bind that cholesterol to the walls of the arteries. In a long enough fast, the garbage collector recycles these cells, releasing the cholesterol and using it as fuel.

Although not strictly necessary, this would have obvious benefits for me. Unfortunately, I had a lot of fat to burn first, and I only fasted for a week, so I probably did not get to this stage in the process.

Why Only A Week?

I had hoped to go a full month, but I was aware it might not get that far; I kind of looked at this fast as a trial run. I've done similar trial runs: for instance, I did several small fasts in 2010, either 24 or 48 hours each.

But I drew this fast to a close after only a week because of unexpected physical reactions — specifically, acid indigestion and vomiting. I only vomited twice, on day 5 and day 7, and the book (along with countless discussion forums on the web) had already told me that throwing up a little on the 3rd or 4th day happens in a few cases. But this happened a few days later than predicted, and neither the book nor any forum said anything about acid indigestion.

Eventually I tracked down a forum post from somebody in a very similar situation, on Dr. Fuhrman's private forums, with a reply from Dr. Fuhrman himself. The TL;DR version: acid indigestion that far into a fast usually indicates toxins in the liver, and if it happens, and accompanies vomiting, you should end the fast. Which was kind of what I had been thinking at the time anyway.


"Toxins," in this context, can include many things most people have in their systems, including biochemical byproducts of digesting meat. You have to achieve a good level of nutritional excellence before you fast, and "nutritional excellence" has a very specific meaning here. Dr. Fuhrman advocates nutritarianism, which is (basically) a rule of only eating foods with very high nutrient content. No meat, no oil, no white bread, no sugar, no alcohol; nothing that does not have a high ratio of nutrients per calorie. It's a simple system, and has worked flawlessly in the past for me, as well as thousands of other people, but many people seem to consider it extreme.

When I first discovered nutritarianism, it improved my health in a staggering number of ways. Most obviously, I lost 82 pounds — with maybe the first 60 or more coming off inside of 6 months — and I kept it off for a year or two, but after a while I got bored and started eating in restaurants like anyone else, and then I gained the weight back. More recently I've gotten back on the wagon — mostly. I've also been sneaking in samosas, fried plaintains, mushroom tacos, olive oil, and bits of chocolate here and there, which is probably what undermined the fast.

I got the impression from brief online conversations with Dr. Fuhrman, back in 2009 or something, that fasting for 7 days at home, on your own, without medical supervision, is a smidgen risky but basically OK. So that's what I did. However, if/when I actually do a bona fide month-long fast, I'll definitely go with medical supervision instead. It's just such a weird experience that it's good to have a guide.

(And again, please remember, this is not medical advice.)

What Fasting Was Like For Me

Fasting weakens you. After a week, I could only stand up for a minute or so at a time. You also become a bit more susceptible to cold. Your body and your energy levels work differently than they usually do, so it's little disorienting, but other than that, it's pretty easy. I wrapped myself in a blanket, watched a lot of TV, and did a little reading. (I wanted to do it the other way around, but reading takes more mental energy.)

Since I did research before doing my fast, I knew I wouldn't have much energy for anything. When my acid indigestion began, it was uncomfortable, but up until that point, the worst part of the experience was being bored, and spending too much time on Twitter as a result.

The actual start of the fast was easy. It took discipline, but it wasn't uncomfortable. Eating the nutritarian way results in very stable blood sugar. It's very easy to go without food for a few extra hours if you're a nutritarian; there are no hunger headaches, there's no feeling of physical weakness, nothing like that. Hunger itself is very manageable if you have stable blood sugar and you aren't eating anything toxic.

In fact, the last time I got on an airplane, I fasted all day. I started the fast in the morning, because I knew it would be less effort than trying to find food with a very high nutrient-to-calorie ratio in an airport or on an airplane. When my flight was delayed by about eight hours (not even kidding), I just continued the fast all the way through to when I finally arrived at my destination, where I already knew a member of my family would be waiting with a big bag of apples, oranges, and bananas. A planned four-hour fast turned into a twelve-hour fast that day, roughly, and I hardly even noticed.

Of course, the week-long fast was different, but not a lot. After several days of no food, you might expect hunger to have turned into this overpowering sensation for me; in fact, I hit a maximum in terms of perceived hunger at the end of the second day, and then it just stayed at that level the entire time. Pretty soon, it faded away like background noise. I did spend an afternoon dreaming up weird recipes to try as soon as I could eat again, and I caught myself absent-mindedly opening up the fridge a few times, but other than that, I didn't think about it as much as you might expect.

At the risk of stating the obvious, I would never in a million years have tried fasting for an entire week if I hadn't already achieved this nutritarian "superpower." If you eat burgers and bread on a daily basis, don't expect to leap into a week-long fast. It would probably be a nightmare.

(And if you're considering a fast, please do assiduous research first, and talk to an actual doctor with relevant training. This is a long post, but I'm only looking at the tip of the iceberg here.)

Ending The Fast

Just like the fast itself, recovery also took a week. I think ending my fast should have only taken three or four days, but it stalled due to a problem. The first few days, you eat only slices of orange or some kind of juicy fruit. Then you add lettuce, then you scale up to meals.

Unfortunately, I bought my orange slices from a store I can't recommend. The slices come in little plastic containers with expiration dates. For a guy who was too tired to stand up, pre-sliced oranges should have been awesome, but they weren't. I got three containers, and on the third, the expiration date was wrong; the oranges inside were fermented and inedible. It was gross, and dangerous.

Again, I'm not a doctor, but Dr. Fuhrman's book mentions the dangers of eating fermented fruit while recovering from a fast. Long story short: it would have sucked. There would even have been a risk of hospitalization, if I understand correctly.

I had to switch to carrot juice and fruit juice, and that actually cost me at least a day. I also went slowly with my recovery on purpose, partly to be sure nothing went wrong, and partly just because I got full very easily. At one point I had to take a nap because I had eaten an entire bowl of soup. It was a small bowl.

My strength returned pretty rapidly, but even after I started back on full meals, it was several days before I could eat normal portions without feeling monstrously overfed. I'm gaining back a little weight, which is very normal post-fasting, especially as your first few days burn muscle and you want to build that back up again. Anyway, the fast is over now, and I'm following nutritarian dietary rules 100% now too. I hope to blog more about this in the future.

Health Is Cybernetic

Cybernetics, a field whose rise accompanied the invention of object-oriented programming, is the study of messages. If you get nothing else from this blog post, I hope you get that health is cybernetic.

For instance, eating a candy bar is not just unwise because that candy contains sugars, which will be inside you once you've eaten the candy. Your body's not a passive bag; it's a complicated organic system full of counterbalancing ecologies. The blood sugar spike which results from eating a candy bar not only adds physical sugar to your internal chemical inventory, it also acts as a message to many internal systems.

Since the human body evolved in a context where sugar was scarce, you probably don't want to actually send out any of the messages which you can trigger by rapidly elevating your internal blood sugar, unless you're actively attempting to worsen your own health. Depending on other health factors, a rapid blood sugar elevation could be the biochemical equivalent of this:

sudo rm -rf /*

If you're like me, you've wondered all your life why the human body does not implement periodic garbage collection. The body creates tons of unnecessary cells. Why doesn't it clean them up? It does. However, you have to trigger that process by sending a particular message to your internal systems, and you send that particular message by going without food for several days.

This is probably because food scarcity happened much more often in every other stage of our evolutionary history than this one. But don't ask me why; it's a legacy system. Be glad it accepts commands at all.

Sorry, No Arguments

Please no critical tweets or flames on Hacker News. I don't read comment threads, and if your tweets annoy me, I'll just block you. Please just show some self-respect and save me the trouble. This also applies to anyone concerned for my health. If you want me to disagree with Dr. Fuhrman on any health-related topic, it probably won't happen. His books have already saved my life at least once.

PS: I Am Not A Doctor

You got that, right? Just in case: I am not a doctor. Happy to answer polite questions, but my advice to you, in every case, will ultimately be "ask Dr. Fuhrman."

Although probably unnecessary, I've prepared a Venn diagram to illustrate.