Totally this. I know once I moved out of home and started feeding myself, I made friend with some of the dietetics students at Uni and picked their brains on how to completely change my diet. Even then, they were talking about gut biomes and how to have a healthy one. Even before I started to seriously lose the weight, the change in diet made such a massive difference in how I felt. I honestly think if fats tried it for a month, even without making an effort to lose weight, the change in how they feel would have such a massive difference to them it would kick start them going to the gym and being more active. I think something people forget is just how truly miserable being fat is. I was a good fifty lb overweight and even that was enough to make me feel like complete and utter shit, all the time. I cannot imagine how truly awful the loves of people who are 300, 400lb are