There’s a lot of talk about fasting these days in the media, with some people touting its superhuman benefits, and others calling it crazy and dangerous. What do we make of it?
, a critical care doc in Ottawa and the man behind Solving Healthcare Media had a great interview this week with Dr. Jason Fung, the “OG” of lifestyle medicine for the treatment of diabetes. Fung was probably the first person to recommend fasting for diabetes management and weight loss, and is largely responsible for kicking off the trend we see today.I’ve written here before about Dr. Fung’s books. What I love about his writing is that he’s able to break down complex ideas and make them into relatable reading that’s easy to understand. And this interview is no different. His take on fasting?
“Fasting is just any period of time that you don’t eat,” he says. He also notes that any criticism of fasting is, quite frankly, “stupid.”
“In fact, it’s such a normal part of the day that the English language has a word: breakfast. It’s when you break your fast.
“It’s not some weird and cruel and unusual punishment. It doesn’t mean 40 days and 40 nights. It just means a period of time that you don’t eat. How long is that? Well, in the 70’s it was about 12-14 hours. You finish dinner at around 7, have breakfast around 7 or 8, that’s 12 or more hours, depending.
“If you were a bad boy, and you got sent to bed without dinner, you’re fasting more like 20 hours, because you missed your dinner. No problem! Many kids got that, and nobody died, there were no health consequences.”
Nowadays, between early morning floppacinos and late-night snacks, the average American eats 15 or more hours a day, according to a 2015 study. This means that the 14-hour fast of the 70’s has been cut in half. I wonder, could this be a driver of the obesity epidemic?
Dr. Fung doesn’t speculate. But he has seen plenty of patients lower their blood glucose, reverse their diabetes, and lose lots of weight by simply spending more time every day in the fasted state.
That may sound like some bold claims, but it’s actually quite simple.
“Every time you eat, insulin goes up. Insulin tells the body to store away some of those calories. When you don’t eat, when you fast — like when you’re sleeping — then your body needs to use those calories. So insulin falls, and your body uses those calories. That’s a perfectly natural period of time.”
The idea of intermittent fasting, then, is just to decrease the amount of time you spend taking in and storing calories, and increase the amount of time that your body is using the calories you have stored (whether that be the glucose in your blood, liver and muscles, or the fat in your hips and love handles).
If you’re fasting-curious, this one is definitely worth a listen, as is all of Dr. Kyeremanteng’s content. Check it out here. Hope you enjoy!