Longo just put out a review paper.
For more background, here are two podcasts Longo did with Rhonda Patrick
(in both of these, he talks about the markers he looks at.
and his and his book
that includes a lot of info on FMD .
On what is in his FMD, this is from Longo's patent
for treating T2 diabetes with FMD. Note the calories are scaled to body weight.
FMD 1 (5 days): a low protein and low carbohydrate diet containing no or minimal animal derived components. The diet provides 7 kcal/pound of body weight for day 1 followed by 4 kcal/pound of body weight/day for days 2-5. At least 60% of calories are from a composition of fatty acids, preferably 100% from plant sources (with 50% or more coming from coconut oil and nuts including macadamia, walnuts, almonds), glycerol (2-5% of kcal) and 5% of calories from plant-based proteins (soy, rice, other grains)+a maximum of 35% of calories from carbohydrates mostly complex from plant sources. The diet is also high nourishment and provides, on each day, 30-50% of the daily recommended intake for all vitamins and minerals+essential fatty acids, with at least 50% of them coming from natural sources.
In Steven Gundry's Paradox books
(Plant, Energy, Longevity, Keto Code) books , he describes how to DIY an FMD.
Of course, one can just water fast. One note from Longo's presentations is that the refeeding is very important. The fasting or FMD shrinks body organs, while refeeding rebuilds them as new. Also, he's done work with fasting/FMD for cancer patients undergoing chemo with good efficacy. However, he notes you should wait until the chemo is completely out of your system (24-48 hours) before eating high protein (especially animal) meals.
A note to @ Julie G
Julie G wrote:
In the first podcast, Longo talks about a study on MS where they tested rounds of FMD in one arm, 7 days FMD followed by Mediterranean diet for 6 months and the last arm was keto for 6 months. The 7 day FMD followed by Mediterranean diet beat the keto diet. This may explain his antipathy towards keto. Also that none of the Blue Zone diets were keto. He did mention using keto interspersed by FMD for cancer being explored by a group in AZ.