The text says 24-60 hours, but then in the table where they talk about the other studies being considered, a lot of them did 48 hour minimum and as much as 96 hours for some. When I saw the headline I was excited because a 16-18 hour fast really isn't very hard for most people, but 48 hours sounds a little rough. I guess if it's just a one-off event while you're doing chemo it's not that bad, but I'm not about to fast 48 hours once a week for the rest of my life.
Most people have trouble even taking a pill regularly. And that's painless. Regularly self-inflicting pain like hunger for 40+ hours at a time has absolutely no hope of becoming a standard therapy in medicine. The percentage of patient compliance would be in the single digits.
I don't even know how people fast for that long. I start getting head-aches and feel awful long before that. So just deciding to fast for 48 hours/week seems untenable to me.