A little more than a month ago I came across a BBC program on the subject of fasting. You can watch the whole thing here.
If you don’t have a whole hour to watch I recommend picking up around the 36 minute mark where they start discussing intermittent fasting, or alternate day fasting. The basic concept is to alternate between fasting days and “feasting” days. A fast day consists of 400-500 calories for women or 500-600 calories for men. (You are encouraged to drink all the water you want on fast days). On the feed/feast days you eat whatever you want.
What are purported benefits of alternate day fasting? All sorts of things according to the researchers interviewed. Here are some mentioned in the documentary:
- Weight loss. It turns out that people doing this intermittent fasting don’t normally eat double their daily recommended calories on feed days. They are more likely to eat about 110% of recommended caloric intake so there is a net calorie deficit every week and that means steady weight loss.
- Reduced blood sugar levels. Warding off diabetes is always a good thing, right?
- Reduced levels of triglycerides, bad cholesterol, and blood pressure. They say this is a good thing. Reportedly reduces risk of heart disease and whatnot.
- Improved brain function. Mice on intermittent fasting remain mentally sharp far longer than the mice that were fed well daily. The theory is that humans see similar benefits. Fasting reportedly causes brains to grow new brain cells. Researchers interviewed for the piece think that this is an evolutionary survival mechanism; as we fast our brains quickly get stronger to give us better odds of wrangling up some food to stay alive. (I’ve been told that other studies indicate fasting has been shown to improve student test scores as well.)