In order to lose weight or maintain a healthy weight, you need to understand the reasons people are overweight:
the incentives they feel for maintaining a healthy weight (younger & dating-->more careful about what you're eating)
the food they're eating
the food choices of the people around them
the amount of sleep they're getting (less sleep-->more stress / cortisol-->more eating)
the amount of physical activity they do in a day (office job-->less physical activity)
also, talking about "going on a diet" is absurd if your goal is to keep the weight off. In order to maintain a healthy weight you need to permanently change the foods you are eating.
Here's an interesting experience I had:
One time I was in a super-market and on a whim bought a package of Oreos and three pints of Haagen-Dazs. I ate all that stuff over the course of two days. Before I bought the Oreos/ice-cream I was very, very good at telling what my body wanted when I felt a particular craving. But in the days after I ate the cookies/ice-cream, my ability to detect what my body needed was a little messed up: for example, I would go a few hours without drinking water, and my body would need water and start to go "HEY WE NEED SOMETHING", but I would find myself craving ice cream instead. I think the problem is that our brains have a limited number of ways to go "Ahhhh that's good" or "Hey! Do something!", so when we get a feeling that says "Hey! Do something!" we have this tendency to think of whatever made us feel good in the past. Or something like that.
Thought: One thing that may keep people from eating fruits and vegetables is that, to have a good experience, you need to know how to choose the specimens that are going to taste good. There's a lot of variability, and if you don't know what you're doing, you're very likely to choose something that you won't like the taste of. This idea also applies to knowing how to prepare and eat the fruit. If you cook broccoli correctly it can taste great, but if you don't do it correctly (which is easier than doing it correctly), it won't taste good and you're not likely to want to prepare it again.
Summary: He found he could put on muscle faster if he didn't do IF, but that it was harder for him to stay lean.
He said he'll also switch up his diet depending on his situation. For example, when he went to another city and didn't have as much control over his diet, he switched from his normal diet to IF to accommodate that lack of control.
Very interesting. This reminds me of that guy who has that system that he sells. Someone I read about online said that it really works, but he ended up feeling depressed when his body fat percentage got too low.