I wrote a couple years ago about the "Bahadori Leanness" program. A study done on it is here. The program calls for replacing a meal with exercise. This essentially creates a "mini-fast".
The program got really good results in the study, and I was surprised by that. After thinking about it, I realized that probably a good chunk of the participants simply ended up with a condensed eating window.
The program says you can replace either breakfast, lunch, or dinner with a light aerobic exercise session. The author mentions he skips breakfast, while the paper also mentions that many participants chose to skip dinner. Either of these effectively creates a long (probably 16 hours or so) time of fasting followed by a shorter feeding window.
So this may be the "secret" of the program, so to speak. It could be thought of as a precursor to LeanGains or something along those lines, as it shares the same common structure.