Calories in vs calories out. That's what energy balance is. And that's supposed to explain in very simple terms why "we" ("I") are fat. Burn more calories than you consume and you will lose weight. Burn less calories than you consume (e.g., eat too many calories) and you will gain weight. Sure seems simple enough. But that's simplistic. Not simple.
There are also other factors involved-hormones for one. And I'm not just referring to the hormones most people think about-estrogen and testosterone. There are many others, like ghrelin for instance, that impact how we eat and what happens to the food after we eat it.
So glancing at a fat person's cart in the supermarket and presuming that she is fat because she seems to have emptied out the chips aisle isn't a fair assessment.
Okay. Chances are if you (I, we, whoever) eat chips and drink soda and eat McDs and gorge on ice cream and never get off the couch...chances are you are going to get fat and stay that way until you make some major changes--hormones notwithstanding.
But even if you eat moderately, with occasional interludes of immoderation, your hormones, your heredity, your age, your gender, your state of mind, may be working against you. That's why your neighbor might be chowing down on ribs while you eat fish and only one of you gets fat!
And that's why I'm angry at my husband today. Not his fault. Well, not his fault because he was born a man and therefore loses weight more easily than a woman. But, still, I'm allowed to be mad at him. We eat together. We cheat on our diets together. We are both bad and good influences on each other. He eats bread, he uses butter, he adds sugar to his coffee. These things he does every day. He only exercises once a week or so because of time constraints. I, on the other hand, virtuous woman that I am, do not eat bread, do not use butter, do not use sugar and work out two hours a day. I lose nothing. He loses one pound.
Justice? Where is the justice!