OpenTube

Valter Longo on Fasting-Mimicking Diets and Longevity

Stanford Department of Medicine

79,004 views

What can fasting teach us about aging, and can the body receive some of its benefits without giving up food completely? Valter Longo, PhD, professor of gerontology and biological sciences, director of the Longevity Institute at the University of Southern California, and author of The Longevity Diet, joins The Future of Medicine for a wide-ranging conversation about nutrition, fasting-mimicking diets, protein, chronic disease, and the biology of longevity.

In this episode, Longo traces an unconventional path from aspiring rock guitarist to longevity scientist. He describes how the early death of his grandfather and the striking differences he observed between relatives living in Italy and Chicago helped shape his interest in why people age and develop disease.

Longo explains how experiments in yeast led his laboratory to study the effects of sugar, amino acids, and fasting on lifespan. He also discusses the development of the fasting-mimicking diet, a five-day, low-sugar, and low-protein eating plan designed to trigger some of the biological responses associated with fasting while still providing food.

The conversation also examines caloric restriction, time-restricted eating, breakfast skipping, and today’s enthusiasm for high-protein diets. Longo distinguishes between short-term changes in weight or metabolic markers and the much harder question of whether a dietary practice improves long-term health.

Together, Longo and host Euan Ashley explore what scientists are learning about nutrition and healthy aging, why extreme approaches can carry tradeoffs, and how carefully designed dietary interventions might one day become part of preventive medicine.

Thank you for watching!

Subscribe for more conversations about groundbreaking medical science and the future of healthcare.

Listen to the podcast: https://thefutureofmedicine.buzzsprou...
Subscribe to our channel: @stanforddepartmentofmedicine
Learn more about us: https://medicine.stanford.edu

Chapters
00:00 Diet Longevity Link
02:53 Music Career Path
06:33 PhD Rock Band Tour
08:49 PhD Pursuit Reason
11:57 Science and Music
15:02 Aging Field Skepticism
18:02 Yeast Aging Study
20:17 Evolutionary Biology
22:59 Fasting Mimicking Diet
26:15 Caloric Restriction Study
30:04 FMD Mouse Study
33:05 Protein Intake Debate
35:43 Fasting: Short vs Long
40:45 FMD Reverses Markers
43:20 FMD: Evolutionary Mode

20 Comments

@StanfordDepartmentofMedicine Creator 1 month ago (edited) Pinned

For the full recording of Dr Longo's March 24, 2026 Medicine Grand Rounds presentation, visit https://youtu.be/FXbanqer1fQ?si=OZtUEDSHK_wu1e-v.

@mikexpoker3275 1 month ago

This video is a classic example of 45 minutes of high-level scientific information that can actually end up confusing or misguiding the viewer. When you spend an hour explaining how popular health interventions (like 16:8 fasting, keto, or high-protein diets) might benefit you in the short term but potentially harm you long term—without leaving the audience with clear, concrete best practices—it leaves the listener more paralyzed than informed. Great knowledge needs actionable direction, otherwise, it just creates friction for people trying to improve their health.

@romateutube 1 month ago

Interview cut when it was getting interesting. The chat about his music background could have been short to actually talk more about his research.

@elenamartinez7358 1 month ago

Dr. Longo is the reason I stopped eating a Standard American Diet ❤

@sapa-kr 1 month ago

Our Austrian archbishop König fasted for more than twelve hours, his last meal was at 3 p.m. and he died in old age, he was 98 years old.

@belindas7299 2 months ago

My FMD fasting hero! So thankful 🙏🏻 He's humble and smart, met him in Genova in May. Been learning so much from and because of him. Wish I could nominate him for the Nobel Prize. Interesting interview, thank you

@jlvandat69 2 months ago

After ten years of 6:18 Intermittent Fasting, I am hesitant to change the routine, even given the "In the long term it will kill you" comment by Dr. Longo. The studies showing a potential link to cardiovascular issues is certainly worth considering, but for people like me that have experienced excellent overall results, e.g., sustained weight loss, much improved biomarkers, lower blood pressure, improved cholesterol numbers, better sleep quality, and maintaining a good exercise routine it seems a bit premature to revert back to a longer "feeding window." I'd like to see results from very long term human studies, e.g., a decade +. Having said all that, we're all different and my style of IF might be deadly to someone else. And how we feel is very important. Our bodies are very good at telling us if we're chronically deprived of adequate nutrition, e.g.

@alexi2460 1 month ago

Wonderful interview, love Dr Volter, he has influenced me alot 80 yrs now

@klyeokl 1 month ago

"Doubling of cardiovascular mortality in people who skip breakfast..." are you sure Dr. ?

@gaBetibu 1 month ago

. . . fun, fascinating interview - from great Interviewer questions to interesting responses . . . GBU . . . 🙂

@mellon7396 1 month ago (edited)

The half day/12 hour fast has always made sense to me as something we evolved to function under. Early hominids foraged and hunted in daylight, and wouldn't have located enough food immediately upon waking up, they would have spent time searching for it. I try to avoid eating for about 12 hours, with an early dinner and no snacks at night. And I never miss a good breakfast. Maybe it's just luck, but so far I'm still fairly healthy in my 70s.

@ramanipoonehela812 2 months ago

very good interviewer, asking relevant questions.

@claudiahost8673 1 month ago

You were a visionary when starting out. Thank you for not letting critics dissuade your interest. Afterall, people trying to save trees were made fun of and called tree-huggers. Medical doctors made fun of Pritiken. And the media made fun of the phrase, "you are what you eat."

@Chief_trader 3 weeks ago

ainda bem q nunca pulo o café da manhã.. pulo a janta

@vinyl_audio_for_life 2 months ago

Valter is a breath of fresh air in the field of longevity. My own research aligns with the work of many of the pioneers in this space, but Valter has done something truly remarkable—he has made the science practical.

The reality is that fewer than 5% of people will consistently follow the advice of longevity experts because, despite its scientific validity, it can be difficult to implement in today's world. Valter's research and the development of the Fasting Mimicking Diet (FMD) are nothing short of brilliant. He has transformed the proven benefits of fasting into an approach that is practical, accessible, and sustainable for everyday people.

I have immense respect for those who are not only scientifically rigorous but also able to translate their knowledge into real-world solutions. In my view, Valter couldn't have made fasting any easier for the average person.

@marcoalmeida6774 1 month ago

I checked Valter Longo's book. It's only marketing for his packaged diet. Shame. He sounded promising.

@revis7927 1 month ago (edited)

A major hospital in the Netherlands (LUMC), in close collaboration with Valter Longo, applied FMD to 131 breast cancer patients undergoing simultaneous chemotherapy. According to Valter Longo's animal / mice studies, FMD was supposed to have an effect on cancer. However, the hospital discontinued the FMD project in 2025 because, after five years of follow-up, it became apparent that the patients who had strictly followed the FMD showed no statistical improvement in Overall Survival or Disease-Free Survival.

@cheng006 1 month ago

Everyday some expert turns up with a new take on how to eat, what to eat and when to eat.

@GodGodDammitDammit 2 months ago

How can we listen to the talk Longo gave that day?

@SVSeaChange 1 month ago

I found this both interesting, for the fact that Longo is a prominent researcher in longevity and fasting, but very annoying in that he claims negative long-term effects from 18/6, 16/8, and even 14/10 fasting regimes. I cannot find the meta-analyses he claims show this, and I am a biological scientist who knows how to find them. The only information for humans is a dubious study that was only presented at a conference and never published, to my knowledge, and which has been criticized for deficient methodology and other limitations. As an originator and prominent proponent of fasting mimicking diets, including multiple patents and other financial interests, he is hardly unbiased and these conflicts should have been acknowledged. This is not to say that FMD might not be useful, and I am game to try it myself at age 70 with the classic set of metabolic disease including chronic kidney disease, but for now I am content on a 14/10 regime. I anyone can point to these supposed published meta-analyses, please share them.