People often fast for cosmetic, religious, or medical reasons. About 14 percent of American adults have reported that they have fasted to help control their weight. But I have begun to fast intermittently because it's the natural way to eat -- or not eat. That fasting may appear at first glance to be unnatural just shows how far we have departed from our heritage. Eating three squares a day is certainly not what our paleolithic ancestors did. And if our paleolithic ancestors seem light years away from modern humans, just remember that the paleolithic period extended until the agricultural revolution, which was only about 300 generations ago. Genetically, we have hardly changed at all since them. Articles by Dr. Michael Eades on his "Protein Power" blog first attracted my attention to intermittent fasting. The more I explored intermittent fasting, particularly in the work of Dr. Loren Cordain, like his book, The Paleo Diet, the more I knew that I had to check out that experience for myself. In the past couple of weeks I made two intermittent fasts. The first was for 12 hours from sunrise to sunset and the second was 24 hours from dinner one night to dinner the next. I drank only water, lemonade, and tea (both black and herbal). None with any calories. And plenty of it. My 12-hour fast was similar to that of Muslims during the month of Ramadan. But hardly the same and not as challenging. Since Muslims are the experts on fasting, I consulted with an imam, Ibrahim Kazerooni, before setting forth on my latest dietary experiment. He is both a friend and a member of my diabetes support group. Ibrahim explained that Muslims can't even drink water while fasting during the month of Ramadan. Their fasts last from 1 and 1/2 hours before sunrise until dusk. (As a Shiite Islamic priest, or imam, he was an Iraqi dissident who Saddam Hussein repeatedly imprisoned until Ibrahim was able to escape from Iraq in 1974; I understand that followers of Sunni Islam fast from dawn to sunset.) "Take it easy at first," Ibrahim explained. "Just do one day to start." He told me that the fast was beneficial for his blood glucose level, even it it was sometimes a bit too low. "It was no problem when I took my diabetes medication at night." People who have type 2 diabetes, as Ibrahim does, need to be careful of what they eat late at night when they break their fasts. They can lose weight, "if they don't overload on sugar and starch." He said that he lost seven pounds this time. Now, after two fasts I am even more positive than I was from reading Drs. Eades and Cordain and from talking with Imam Kazerooni. I did have brief headaches near the beginning of each fast. And a bit of a sore throat for a short while as I hiked during my first fast. At one point on the trail I felt hunger pains in my stomach for a few minutes. But I was amazed that otherwise I never got hungry. My mood remained at a high level throughout. Physically, I may have even gained energy. For example, on my walk to the post office during the second fast I even did some intermittent jogging, something that I hadn't done for several months. I don't take any diabetes drugs or other prescription medication. My blood glucose level once went down to 68 mg/dl, about as far as anyone with diabetes would want. The first thing on the morning after my second fast it was at 80 mg/dl, just below the 83 mark that Dr. Richard K. Bernstein, the leading exponent of a very low-carb diet, says that is the appropriate average for anyone. I lost 0.8 pounds, and now my weight is the lowest in eight months. Later I thought to investigate the peer-reviewed articles on Medline and found this: "Persons with Type 1 diabetes can participate safely in prolonged fasts [more than 25 hours] provided they reduce their usual insulin dose significantly and adhere to guidelines regarding glucose monitoring and indications for terminating fasting." People with type 1, unlike me, absolutely have to take insulin. And of course my intermittent fasts have not been "prolonged." I also found other studies indicating other benefits of intermittent fasting, including one that concludes: "Reducing energy intake by controlled caloric restriction or intermittent fasting increases lifespan and protects various tissues against disease..." Another study reported: "It has previously been shown that fasting for the biblical period of 40 days and 40 nights is well within the overall physiological capabilities of a healthy adult." The experience freed me from the self-imposed tyranny of assuming that I just had to eat breakfast, lunch, and dinner. Skipping those meals even saved me lots of time in food preparation and eating. In conclusion, the experience was so rewarding that I will continue intermittent fasts of various lengths. But not more than the biblical 40 days and 40 nights.