Obesity is probably a combination of many factors...
It is interesting to see how much weight people can lose when on serious but still somewhat sensible diet restrictions and a planned and consistent exercise program...
Look at the contestants on the biggest loser for examples...
Since I am of similar age to you, we both probably shared somewhat similar activities and schedule of activities when we were quite young, that of constant and sustained and quite rigorous daily exercise with strained muscles and aches and pain from over-doing it on a regular basis as almost a constant of daily life for us...
Time spent indoors was often viewed as time wasted regardless of if the sun was shining or it was raining...
Every day was a onging series of running, jumping, climbing bicycle riding, horse riding, water sports and and unending competition of physical performance and stamina building with both siblings and the neighborhood kids...
Additionally of course the ingredients in the processed foods we ate then, often in copious quantities were probably somewhat less processed, and often "made-by-mum" from known ingredients rather than purchased from a shopping center...
Compare that with kids today and the daily TV watching/ computer games/ lounging around that seems to be more common for massive portion of the day coupled with the diet rich in processed/manufactured sugars and lots of mystery chemicals and fats...
It does seem that many kids just dont have a chance and once childhood habits become set in place, adult obesity would seem to be inevitable...
While exercise and diet are not a complete and total answer in all cases as even in those days we had obese kids and adults, it would seem that the change in exercise and diet profile that we have seen could tend to result in a spread of the negative impact of these changes to a larger portion of the population hence more widespread obesity...
