I tried one if those weight loss food systems once. I'll say it's not really a scam, but if you knew what you were doing, you could do better.

They basically controlled what you could eat so that you ultimately consumed less calories so you could lose weight without having to count calories, or manage macronutrients. But it was also expensive and the food was terrible, and as you said, as soon as you get off of it, you go back to the way you were. ****

However, I do have to thank it for opening my eyes and helping me understand calories and macros a whole lot better. Not to mention proving to me that I could in fact lose weight, back when I thought it was just the way I'd be forever. Because then I started looking into why it worked and what I needed to do to stop buying that crap and eat real food again.