I dropped multiple dress sizes by improving my nutrition. I also got my younger son to drop weight without dieting by buying him dark chocolate as a means to discourage him from eating chocolate pop tarts. I learned he was eating chocolate pop tarts all day, concluded he was specifically craving cocoa and found him a better source of cocoa so he could get enough cocoa with fewer calories.

I suspect obesity is frequently due to getting too little nutrition while getting enough/too much in the way of calories. You keep eating precisely because you are malnourished and it fosters cravings.