the only way you'll get an exact scientific method is if you contact a researcher who is creating a calorie pill to increase life longevity. no shit, it's legit. it's based on African people's diets because they have very low calorie diets, but live longer and look younger.
I think everyone's body will react different to intermittent fasting. the concept is just to go half a day without food, or even a whole day with just a dinner and that can be large but guarantee your eyes will be larger than your stomach.
I tend to burn 1500-3500calories a day when doing industrial electrical work & racquetball/may thai/BJJ & weight training 4-6 days out of the week I will either sporadically just miss about 4-8hrs of food during the time but mind you I will be the hulk and a little slow minded for the first few weeks.
other times I will have a breakfast so I'm not slow and weak, then miss breaks/lunches and just wait for a dinner. no protein shakes or soda.
when I go hard, it's primarily on a stacked cutting cycle that includes an appetite suppressant such as ephedrine & caffeine.
I can't tell you exactly what to do except to just try randomly missing meals and try to prolong longer with time in the diet. yeah your missing out on nutrients but I don't think a few hours will eat your muscles away when you'll be loading up before sleep fasting.
just my 2 cents and we all know I'm not a pro, expert or md.