From reading and watching and trying a lot of these over the years, the primary reason why they work is because overall you are consuming fewer calories. If you track your calories via something like MyFitnessPal, it'll be obvious. There are some other benefits but it's mostly to do with your lifestyle and ability to adhere to the diet. If you can only do big workouts in the morning, probably not gonna be able to skip breakfast and lunch. Some of the hardcore proponents of these diets are also on drugs / TRT which skew the results massively. If you're a regular guy with a regular job, your results "may vary".
By the way, never get your woman on any form of IF, including this one. They are built more for snacking on small meals over the whole day, unlike us.
By the way, never get your woman on any form of IF, including this one. They are built more for snacking on small meals over the whole day, unlike us.