um, "changed in behavior ... eating more vegetables" -aka- "diet". So in other words "fad and crash diets" don't work. But "improving your diet" does and always has.
However like you said if you think about your diet like e.g. banning soda, processed food and other unhealthy food, it works wonders. I know the book title sounds cliche but I'm reading "The 6-Pack Checklist: A Step-by-Step Guide to Shredded Abs" by Nate Miyaki and he writes that even if you exercise a lot you cannot or shouldn't eat anything you like.
This wasn't clear to me up until recently because I thought only about calories but not the quality of food like if you are taking enough omega 3 fatty acids etc. I thought as long as I exercise and burn enough calories it doesn't matter what kind of food I eat which is not true.