I never lost weight through increased physical activity because my hunger levels always scaled to match my Calorie burning. Two things that have made major durable differences for me include reducing my sugary beverage intake and increasing my fiber intake. High-fiber foods make me feel full longer so significantly decrease my overall Calorie intake. Snacks like Triscuits and whole grain Goldfish crackers are good for this.
I wonder if there is a way to gamify weight loss or calorie restriction. I mean besides participating on the "Alone" television show (where people go for weeks with very minimal calorie intake). And I wouldn't be surprised if there weren't self-reinforcing cliques of anorexics essentially doing this already in an unhealthy way.