Note, Longo is not a keto guy. His specialty is fasting and longevity, but his version of a fast-mimicking diet (so low in calories that it mimics a fast) isn’t keto. He’s admitted that water only fasting is actually more effective than FMD, just really hard for people; my basic takeaway from his stuff is more about the benefits and results of fasting than what you can or can’t eat on a fast.
New Interview: Valter Longo on Fasting & Aging
anon13588705
#2
Thank you very much for posting this Karen.
“We started testing in cancer patients but realized that they didn’t want to fast. They gave us an opportunity and the motivation to look for a fasting-mimicking diet; a diet that works as well as fasting, but allows patients to eat.” - Dr. Valter Longo from the text under the linked clip above.
In his book, he mentions wanting to find a way to turn on autophagy for aged oncology patients fro whom it wasn’t suitable to fast due to low body weight etc and also children with cancer, whom it is apparently not suitable to water fast.
I don’t have the impression his target audience is keto dieters, rather scientists. His longevity FMD turns down inflammation which is a major personal concern of mine, since nothing has worked yet for that, for me which puts me in a high risk category for cancer eg. So I have been following his results for a few years, with this particular personal interest.
Ketoers get excited about his recommending a plant based diet. I am not attached to any diet, i am just looking for solutions to health issues for my type 2 diabetes (currently controlled/in remission? and my 93yo mother, whom I am desperately seeking solutions for.
I believe Longo says in his book it is the removal of the essential amino acids in his FMD that turns on autophagy, not the low calorie component as seems to be most frequently referred to.
I don’t think I can follow his diet, unfortunately because I have to stay away from lectins which put me in emergency wards fast. It took 3 years of constant yo yo emergency admissions to pin that one down, picked up in passing by a dietitian. 
I am not medically permitted to fast my mother because of her age. However I can possibly get doctor’s permission for her to use his packaged FMD for 5 days. I am working on it!