Intermittent Fasting Good, But Don't Do It Yet? The Expert Double-Bind Strikes Again

Science Daily saw fit to reprint a EurekAlert announcing that a "Study finds routine periodic fasting is good for your health, and your heart."  The article describes research done by a team apparently led by Dr. Benjamin Horne, PhD, MPH.  The team had some people fast for 24 hours and recorded the changes in the participants blood levels of cholesterol and hormones.  


They found that during the fasting period, blood levels of both LDL and HDL increased.   According to the article, Dr. Horne explains the findings this way:

"Fasting causes hunger or stress. In response, the body releases more cholesterol, allowing it to utilize fat as a source of fuel, instead of glucose. This decreases the number of fat cells in the body," says Dr. Horne. "This is important because the fewer fat cells a body has, the less likely it will experience insulin resistance, or diabetes."

I agree with the first sentence, but I doubt the second.  I know of no way that elevations of blood cholesterol influence cells' fuel use.  If what he says was true,  high serum cholesterol would indicate a metabolism that burns fat in preference to glucose, and raising cholesterol would treat obesity.

Assuming Dr. Horne actually said this, I think he has cause and effect confused.  When fasting, the body releases fat from adipose for use as fuel, and cholesterol gets released from those tissues at the same time.

Dr. Horne, I suggest that you get a copy of Eat Stop Eat by Brad Pilon if you want to learn how fasting works, or at least consult a standard physiology textbook.  ESE has an extensive bibliography referring to dozens of studies of the effects of fasting.  You will find that the textbooks and numerous research papers tell us that fasting lowers insulin, and the reduction of insulin allows the body to use greater amounts of fat as a fuel.

Next he says that this process "decreases the number of fat cells in the body."  Wow!  I have never seen any evidence that any method short of surgical excision (lipectomy) can reduce the number of fat cells in the body.  So far as I know, fasting or dieting can reduce the amount of fat stored in the fat cells we have, but not the number of fat cells.   Dr. Horne,  if you have evidence that fasting can reduce the number of fat cells, I sure would like to see it.

Horne's team also confirmed previous research showing that fasting has profound effects on human growth hormone (HGH) secretion.  Increased HGH protects muscle mass and increases fat metabolism.  Horne's research found that "During the 24-hour fasting periods, HGH increased an average of 1,300 percent in women, and nearly 2,000 percent in men."

So this fasting thing sounds pretty good, eh?  Don't get carried away:

While the results were surprising to researchers, it's not time to start a fasting diet just yet. It will take more studies like these to fully determine the body's reaction to fasting and its effect on human health. Dr. Horne believes that fasting could one day be prescribed as a treatment for preventing diabetes and coronary heart disease.

I suppose they want to cover their bases, but this kind of "disclaimer" gets my goat.  These people seem like hypercautious nannies wanting everyone to stay "safe," as if going without eating for 24 hours was some unprecedented adventure into dangerous, uncharted territory.  My cynical part read it this way:  "Look, this fasting thing could do awesome things for your health, even prevent diabetes or heart disease, but now that you know that, we want you to go back to sleep.  After all, we wouldn't want to discourage the use of drugs...." 

In nature, most carnivores or omnivores spend a lot of time without food.  Without refrigerators and convenience stores, if you want to eat, you have to hunt, and hunting takes time.  As a result, most non-human carnivores spend a far greater portion of their lives in the fasted than the fed state. 

Ethnographic records also indicate that most hunter-gatherer tribes have traditionally eat only one or at most two main meals daily, in late afternoon or early evening, which means that the people fast at least 16 hours and often 20-24 hours almost daily.  We can surmise that our paleolithic ancestors also spent far more time in the fasting than in the fed state.  Thus, rather than having to justify intermittent fasting,  which occurs as a matter of course in natural circumstances, advocates of eating more frequently need to prove the safety of frequent feeding, because it departs from the paleolithic default.

I fast 16-17 hours almost every day of the week and usually have at least one fast lasting at least 20 hours once weekly.  I almost always do my heavy and light training after at least 16 hours of fasting.  I've been doing this for more than two years with only  positive results.  I highly recommend it for weight management and health enhancement.  Don't let the nannies discourage you from doing something absolutely natural.