About 2 years ago I put myself on a vague version of the 5 + 2 regime, but cut right down on carbs and wine. I immediately lost half a stone, and in a month or so had gone from 14st 7lb to around 13st 5lb. In the ensuing weeks I touched 13st. I wasn't particulary disciplined or obsessed, but I was in control, it felt good, and I felt less tired and much sharper. I came off the 'regime' after a few weeks, and it held at around 13/7 until last Christmas, when I quite suddenly put some weight back on my tum again. I'm not really sure why, as I eat well, but not much, and am steady on the vino.
My old mate had to eat around 4000 calories a day to keep himself at a steady 35 odd stone. He didn't move much.
He doesn't move at all now, the silly sod simply couldn't get a grip on it. He picked up C19 early, and his old heart said 'enough'.