What's the deal with intermittent fasting?

Perry Wilson (0:01)

Emily, this is our first episode that I think you might be, like, viscerally opposed to. Like, I think this intermittent fasting is something that would anger you at, like, a deep level, because I don't think I know anyone who eats more frequently than you do. When is the last time you ate? Tell me that.

Emily Oster (0:21)

Well, I ate on the way over here, my third breakfast.

Yeah, 10 minutes ago. I object to that. First of all, I want to say that I was opposed to the sun. I'm not into it. No, we've done a lot of episodes full of things I don't like, weird peptides. But it is true that I like to eat very frequently. But, okay, how long is the longest you've ever gone without eating? Like, not like, okay, not like one time when you had the stomach flu, but like on purpose.

Perry Wilson (0:51)

No, never on purpose. But because of circumstance, when I was a resident, and this was back in the day when we would do these 30-hour shifts, which is a terrible thing, and no one should ever do that. But so I would start at 6 a.m. and I would leave the next day at 1 p.m. And there was definitely a day or two in there where I like didn't eat for that.

Maybe I had lunch or something, but I remember being so exhausted and hungry on the way home. And I would stop at this place called Bocellas in Havertown and get a chicken cheese steak, like a 14-inch chicken cheese steak, and sit on my couch and eat the whole thing, and then just lie down on the couch and then sleep until 10 at night. That was, it's not healthy. But that was a long time.

Emily Oster (1:37)

It's not good for you. It's not good for the people whose kidneys you were working on. It's not good for anyone.

Perry Wilson (1:42)

It's not. Emily, you really believe in fueling your body. You're an exercise person.

I thought that fasting would be something that is anathema to your world view.

Emily Oster (1:56)

I think that's very interesting.

I like to eat frequently before exercise, but I will say that I don't eat after 6:30 PM until the next morning. So I'm not a late night snacker. I do a thing that some people would view as a form of fasting, where you don't eat while you're asleep. That's my kind of fasting, where you don't eat literally during sleep. I have occasionally eaten during sleep, to be clear, but I try not to sleep eat.

Perry Wilson (2:26)

I keep a side of bacon right on my bedside table.

Emily Oster (2:30)

I'm surprised it's not like the cheese from the mac and cheese, that you have a little spoon and a container of that next to your bed.

Perry Wilson (2:38)

Yeah, you can stir it in water a little. Yeah, sounds great.

Emily Oster (2:41)

All right. Let's talk about intermittent fasting, something that I am not a fan of, but we'll find out. Maybe it'll change my mind.

Perry Wilson (2:48)

We'll see.

Emily Oster (2:49)

Probably not, though.

I'm Emily Oster. I'm an economist and a data expert.

Perry Wilson (2:55)

And I'm Perry Wilson. I'm a medical doctor.

Emily Oster (2:58)

It's Thursday, October 15th, 2026, and this is Wellness, Actually.

Perry Wilson (3:02)

Because you're getting a staggering amount of health and wellness information nowadays from every source imaginable. And some of it is awesome.

Emily Oster (3:10)

And some of it is, well, actually bullsh**. Fortunately, we're both people who know how to read studies, how to parse the data, and can tell you what's worth thinking about and what you can safely ignore.

Perry Wilson (3:24)

But before we dig in, a note that this podcast is for educational purposes and should not be construed as medical advice. We don't know your unique situation, so talk to your doctor for personal health decisions.

Emily Oster (3:36)

This week, we're asking, what's the deal with intermittent fasting? Perry and I will give the official smash or pass, and then we'll get to your question of the week. But first, let's do the health news roundup after the break.

And now for the health news of the week. Perry, Health Secretary RFK Jr.'s establishing a clinic and dedicated billing codes to track serious vaccine side effects. Smash or pass? What do you think about that?

Perry Wilson (4:17)

So, okay, obviously, better data on vaccine side effects is critical. We've talked about this before, but the Vaccine Adverse Event Reporting System is potentially the worst data set on vaccines that could possibly exist, because anyone can submit anything, and it's completely unverified. And as we said before, there are reports in there that people got injected and turned into the Hulk and stuff. It is very messy data. So clearly, we need better data on this.