Personally I'd describe obesity as the natural consequence of placing a collection of truly ancient genes, genes forged over millions of years of incredible and constant dietary insecurity and upheaval, into an insane, calorific, modern day, dietary utopia. In other words? Obesity and overweight are our bodies' normal, natural, responses to the world they finds themselves living in.  --Yoni Freedhoff

You're not going to change your genes.

Odds are very small you're going to move yourself to a plot of land in Montana and start a subsistence farm.  (Sure, you'd probably get to the weight you're working toward but there'd be nobody to see you do it).  So, you may make some changes to your personal environment but chances are you're not going change your extended environment very much.

You can, however, change how you react to your environment.  You have the option to learn to say "not right now".  This is an option our ancestors who experienced "incredible and constant dietary insecurity and upheaval" did not have.  They NEEDED to eat whatever came across their path -- they didn't know when the next food would show up.

YOU do not live in that world.  It is no longer life-sustaining to eat whatever crosses your path.  And yet.....how many time a day do you do just that?