Do you think just being more active is the main reason we were thin back in the day. I remember eating at McDonalds for lunch in high school and drinking cokes everyday. But the cokes I drank was at my after school job at the gas station back in the day when we fixed flats, washed cars and actually pumped gas and washed windows so maybe it was the activity. But I wonder how much high fructose corn syrup in every damn thing and our engineered food has to do with the overweight problem.
I totally think it is an activity (or lack of activity) issue. I teach two classes of juniors in our Jujitsu school each week. Almost all of them have one additional sport they play (most play soccer, or take gymnastics). One fat kid in the class (there's always one). All the rest of them, aged 7 to 13 are thin as rails and in good shape. As expected, the fat kid whines all the time about any of the drills or exertion I subject them to, despite the fact he is in a class designed around throwing people. I remember eating like you did - McD's, Pizza, whatever I wanted. Do any of us remember actually thinking "Whoa, I need to check my sugar intake". Remember Jolt cola? I lived on it. Poptarts, cheetos, pizza, mac n cheese, whatever. Sure, I ate good things too, but nothing stopped me from finishing a whole pizza in high school, if I had my mind made up. Also drank a gallon of milk a day - and not the non-fat version. My mother would scream at me "I just bought this 4 hours ago!!" In high school, I took karate and played football. They beat us so badly in football that I barely had energy to do homework before bed. In gym class, we played a sport of our choice - I chose floor hockey in the gym. We checked each other into the walls, the bleachers, played dirty. More than one kid got hurt. That didn't stop our teacher (who was one of the baseball coaches) from barely paying any attention to us whatsoever. When we got hurt in class, we went to the nurse. When we got home, we didn't complain, and even if we did, our dads told us to quit whining. Our moms would just tell us that if we wanted to play rough, we had to expect injuries. No one thought to sue the school. After football season was over, the bus dropped us off and we got kicked out of the house. We rode bikes. Played "Smear the Queer", or basketball. We invented games with rules that were designed to cause pain, laughed when our friends got hurt (even though we secretly felt bad). When it got dark, we argued about who's mom it was shouting for them one block over. When the street lights came on, we had to be home. If we wore our school clothes outside, we got in some serious shit with mom. When was the last time you saw a bunch of kids playing some homemade sport in your neighborhood? I can't remember. On Halloween, the kids run around and "boo" each other's house. That's about the last time I can recall it. Fucking pathetic. You want to curb obesity in kids? Put your foot in their ass.
Heh, as I sit here remembering the games we invented as kids, I remember one in particular that injured each one of us in turn. Talk about stupid. It was designed like kickball, except you used a basketball and had to hit the basketball with a metal pole that was used as a bat. Ever try to hit a basketball with a bat? The extreme pressurization causes the pole to come back violently and hit the batter, and not in a gentle manner. First guy up broke his nose. Did that stop us? Of course not. Second guy, same pole, black eye. Still, we pressed on, convinced that the guys before us were pussies and didn't know how to do it properly. Third guy, knocked a tooth out. And on it went until everyone had an injury and we all agreed, finally, what a stupid idea it was. Good times.
Tao the guys who do my roofs burn more calories than the guys you are talking about and they do it every damn day for 12 hours a day, they have to be burning 4 to 5 thousand calories a day. Guess what many of them have guts on them, they are strong like ants but are overweight too. Back in the day the same workers were thin, same work, same calories burned but now fat. I don't have a definitive opinion on this but I do have questions. I agree activity is a huge factor but I don't think it is as black and white an issue as you do.
Do you know how much activity must be performed in order to burn 4 to 5 thousand calories a day? Unless you intended to use hyperbole, I call bullshit. Sweating doesn't mean you are burning calories - especially in a high temperature environment. I'll bet you would be shocked at how little calories these guys actually burn, and what they put in their stomach when they get home.