A good read is of course not why you're here, but that's what you get anyway. I cannot say much about the science or legitimacy of the author's claims, but they seem very plausible to me.

The basic premise is that there are a bunch of "Ultra-processed foods" which are behind the rise in obesity levels (along with other health complications). These foods are not only addictive but mess with the body's appetite mechanism, there by shutting down the message that we have eaten enough.

There isn't really a discussion of how exactly these foods do this. Though the argument is partly based on trials, and partly a discussion of Darwinian evolution of foods. In order to survive in the gladitorial supermarket shelves a foodstuff must sell, and sell often. This evolutionary struggle has driven companies to optimise foods, not only for cost, shelf-life, but also for addictiveness. Part of being addictive is cancelling the body's natural system to signal satiety.

On the one hand, this all sounds quite plausible, on the other hand society has been through cycles of 'bad food', before, health alerts over fats, sugars, carbohydrates etc. have all pointed the blame for increasing obesity at different targets. This book argues that ironically those health drives may have made the problem worse by incentivising food companies to work around those natural food stuffs with more synthetic or processed alternatives, such as synthetic sweeteners.

Again, I'm not in a position to judge the claims of the book well, but I can tell you that the information is presented in a very accessible and enjoyable to read manner.