Pros and cons of intermittent fasting

Author David Asprey talks about how and why it works and the different types of fasting you can do.
4:56 | 01/27/21

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Transcript for Pros and cons of intermittent fasting
Dr. Jen on her Instagram We will turn from Dr. Jen and Dr. Robach to talk about intermittent fasting. We have Dr. Jen answering some questions here, but also "New York Times" best-selling author of "Fast this way," it explores the different aspects of fasting, please welcome Mr. Dave asprey, sir. I'm so excited to see you. I was on your podcast earlier this month. We had an awesome hour talking about these things and more. Just so you know,n honor of you coming here, I did my first 24-hour fast yesterday and felt great and did two work-outs while fasting. It can be done. I have tons of energy. You're not a doctor like me or a nutritionist. You have an unconventional approach to fasting. You fasted in a cave for four days. I was afraid of being hungry and acting like a jerk. I figured a cave was the best place to do it. There's ancient wisdom that supports fasting. Dr. Jen, let's bring you in on this. Who can benefit? Are there some people it's not for? It's not for pregnant women, teenagers or people with a history of eating disorder. However, there is a significant amount of very good peer reviewed literature that supports cellular and metabolic benefits from fasting, time restricted eating, the kinds of things Amy and I talk about. It's an option for people. People get worked up when they talk about it. This is not a dictatorship. It's an option for people. There is science to support its benefits, but like anything, there can be risks if taken to an extreme. Right. People do think it sounds extreme. It's not if you're doing it correctly. Dave, what has your experience been like? You've been doing this for a long time. People have lost 1 million pounds on the bullet proof diet with intermittent fasting. I have lost 100 pounds. It can be safe. I don't do it for weight loss anymore. I do it for the energy. I feel better when I do. Explain for people who don't know -- I do a 16/8 regimen. Explain what that is and what you recommend. That means you don't eat for 16 hours. It sounds crazy. All you have to do is have dinner earlier. Sleep eight hours and you already skipped 12 hours. You have a late breakfast, you just went 16 hours without food. All you felt like you were doing is having a late breakfast or early lunch. Most people can do that and feel good, in fact, they feel better. Do we find a lot of people start off because they are trying to lose the weight and then it becomes a lifestyle? If you look at the data, it has been associated with an increase in longevity, a decrease in the incidents of disease states, including cancer, these effects are independent of weight loss. When you look at it, find what works for you. A diet needs to be safe, simple and sustainable. For those like you and me who find this works, there are some real benefits. I don't do it for weight loss. I started it for an anti-cancer approach to my lifestyle. I know you're shaking your head, Dave. How long have you been doing this? Do you ever see yourself saying I can't do this anymore? I have done it most mornings for more than ten years. You feel better the first morning you do it and you didn't spend time and money on breakfast. Then over time your metabolism gets stronger which reduces your risk of type 2 diabetes. You get a long-term return on feeling better now. Any recommendation for folks who say I get hungry during the day? You have to eat the right foods so you don't get hungry. A healthy fat will sustain you longer than carbs. Dave, really, robes was very excited to have you here. She was singing your praises and you delivered. Really good to see you. Hope we see you back on the show Yes. Dave's book "Fast this way" is available everywhere books are sold.

This transcript has been automatically generated and may not be 100% accurate.

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