I'm 5'11, used to be rail thin and was one of those 'quick metabolism kid who can't gain weight even if he wants to' and weighed in about 135lbs.
I got a desk job, grew older and went all the way to 210lbs, which was definitely overweight (if not obese). It was doing a hike that I used to do as a kid with some of my old friend and finding myself out of breath that I decided I wanted to do something about it. Over the last few years I started eating healthier and simply stopped buying snack food (like chips and stuff). I also got myself a dog and made a commitment to walk him every day.
In the last 3 years, I've lost 35lbs (I'm at 5'11, 175lbs right now - which makes me very slightly overweight according to my body mass indicator). We're not talking about hitting the gym like crazy and dieting here... I just take a 30-60 minutes walk every day (And not even, I skip when it rains or it's too cold) and cutting down on the junk food and doritos.
So now... I don't have much respect for people who let themselves go to the point of obesity. It's really not that hard to at least maintain yourself in a decent shape. You may have a medical condition, but ironically, most of the people I know that are fat 'because of a medical condition' eat fast food all the time and barely ever move.
Amd I'm sorry to say guys, but if you're 5'7 and 170ish, unless you're cut out of solid muscles, you're very much overweight.