Image of green tea via Wikipedia

Today is my fasting day.

I have always been a tall, thin guy (well.. I was shorter as a baby) and I do some kind of mild CR (calorie restriction), but I have the same problem as everyone else - it is not very challenging mentally or physically, but socially it is a problem not being able to get lunch at the occasional fast-food joint or pasta place, etc.

A couple of months ago, I read about some promising results regarding intermittent fasting as an alternative to CR. After some brief research, I decided that it was safe (religious people have done it for a long time, after all) and most likely beneficial. I have been a practicing IF:er ever since.

One day a week, often Thursdays, I stay of food and beverages with any calories in them for 24 hours. This means that the only thing I consume is water (sometimes with a squirt of lemon or lime) and plain green tea. I eat dinner Wednesday at about 19.00 (7 PM for the chronologically challenged) and then I don't eat anything until Thursday night's dinner. This is a good schedule, since you don't have to go to bed hungry.

I don't take any vitamins or other supplements during this time. It seems possible that one way that IF works is through hormesis, i.e. that it stresses the body's defense mechanisms. There is even evidence that this is how exercise works and that antioxidants could interfere. I'll write about that some other time.

If I do any exercise on these days, it is either before dinner on Wednesday or after dinner on Thursday. Supposedly, you can do aerobic exercise on an empty stomach, especially if you want to burn fat, but I'd rather not feel weak when I exercise. There are body builders who are on diets similar to IF (like the Warrior Diet and 16/8), to burn fat and define muscle, so I don't think there is any reason to fear loss of muscle mass.

Tentatively, from the worm study linked to below, it seems that one might gain even greater benefits from fasting twice a week or maybe even every other day, but I want to see more evidence before I inconvenience myself. I calculate that the 24 hours that I don't eat are "free". That is how much less I age in a week, if the studies on lower animals apply to humans.

I am definitely more sensitive to stress on my fasting days, but knowing that makes it psychologically easier to remind myself to lose the aggression and relax. It was harder the first one or two times, and I had to drink a lot of water to hide the hunger, but after that it became easier. My body adapted. Now, I think, I might even have a mild addiction to it. I am often unusually mirthful on my fasting days. I doubt those around me notice any difference either way, though.

These are some links from my RSS feeds, discussing the latest findings:

Ouroboros on Intermittent Fasting
Another Media Article on Intermittent Fasting
Practicing Intermittent Fasting Versus Calorie Restriction
Running on empty: the pros and cons of fasting (for some reason, this article has become uglier and without pictures - it used to look nice)

Older studies:
http://www.ncbi.nlm.nih.gov/pubmed/17306982?dopt=AbstractPlus
http://www.longevitymeme.org/news/view_news_item.cfm?news_id=3056
In conclusion, the negative is that we don't know enough on how IF affects the more advanced mammals (even though there are some evidence from religious fasting). The positive is that it looks very effective on the types of animals that die quickly enough, that we have had time to get results. In the worm study, linked to above, it is even more efficient than CR.

Since CR is effective even if your food intake is irregular (it is the total amount of calories over time that matters), IF at least helps my mild CR. Interestingly, IF and CR seem to rely on different genetic pathways.