The difference is that the person on the left doesn't do this very often. The thin people that say they do are full of it. They either overestimate just how much they eat, or how often they splurge. Getting fit doesn't necessarily include giving up all the foods you love, it just means taking responsibility and eating in moderation. This is what took me a long time to wrap my head around. I didn't get how I could see fit people eating the same foods as me and yet maintaining a nice physique. 