When my neighbor recommended this book, I thought it was going to be about shrinking the inner critic inside your head so that you can accept yourself and love yourself enough to take better care of yourself or something. It's not about that--the author was actually a movie critic, and she's the one shrinking.
I found this book way more helpful than I ever expected. I had been stuck for a few years at the stage of thinking I wanted to lose weight but actually being more committed to staying fat/safe. This book found me right when I actually became ready to lose weight, and it changed my perspective enough to help me really do so.
Two main things struck me:
1. There's a scale of not-great, better, and ideal behavior (I don't remember her specific words, but this is the idea). Instead of seeing things as all or nothing, just try to move a little in the direction of "ideal." Over time, that adds up and starts creating results, which you can use to fuel your motivation to be even better. The idea of giving up all desserts forever is not one I can imagine myself agreeing to (or sticking to), but eating smaller portions of dessert on fewer occasions is doable. Going to the gym every day? Not gonna happen. But walking in the woods more often? Sure. And above all, not seeing everything as black and white, "well, I just ate a chocolate chip, so I might as well eat all the cookies I'm baking and then go out for ice cream as well, so I can get it out of my system and eat only twigs tomorrow," but rather, "hey, a cookie or two is maybe not-great eating, but these cookies were worth it. Other than that, I'm eating 'better' or 'ideal' like I usually do."
2. It doesn't help to make everything such a big deal or be extreme about anything. If I try to eat 1200 calories or less every day, I get really fucking hungry and obsessed with food. If I think about wanting to lose 45 pounds, I just get discouraged and give up. But if I just eat a little better and focus on losing the next 4 pounds, that's super motivational and effective.
Also, I'm not sure if this was actually in the book or a coincidence, but I know a lot of people recommend visualizing yourself how you want to look and/or doing what you want to be able to do, to help yourself stay motivated. I was having a hard time doing that, but I had reason to believe that I might fit into a smaller size of pants. I didn't own any pants that size, so I decided to do a 3-D visualization of myself wearing smaller pants. I took myself to the store and tried on smaller pants, and not only did they fit, but my shirt size had also changed from large to medium!
This was way more powerful than I expected, because once I had lost a few pounds and wanted to celebrate, I didn't do what I usually do and go get some ice cream. My commitment to my new pants helped me move past the point where I'd usually stop and then gain weight back, and instead stay on the wagon and keep going.