<human>: Give me a shortened version of the text

I've seen a lot of posts on reddit where the subject of obesity comes up and all of the resident experts (everyone, it would seem) chime in claiming that pretty much all obese people got that way because they eat really bad foods, don't exercise, and are living cartoon stereotypes of fat people. I've seen a lot of people saying that blaming metabolism is a cop out and that it's just laziness that leads to obesity.

As a fat dude, a lot of these things don't add up for me. I take daily multivitamins, have a workout regiment, drink a gallon of water a day (literally, I have a stock of gallon jugs and drink one a day, at least),  eat a high protein diet, and avoid fast food as much as possible. My friend on the other hand, leads a very unhealthy lifestyle. He says he never exercises, plays videogames all day, never eats vegetables and pretty much lives on fast food. The times we've eaten fast food together, he always gets something that makes what I'm eating look like a Happy Meal. He is seriously the laziest dude I know, but weighs maybe a hundred pounds less than I do. And he's not even the only friend I have that this applies to.

My question is: what is the factor that I'm missing that lets him do whatever he wants and remain a reasonable weight, while I have to alter my life to see even the slightest change, if any change at all?
<bot>: If weight depends entirely on exercise and diet, and metabolism is just an excuse (as many redditors claim), why do I weigh so much more than my friends who eat more (and worse) and exercise less than I do?