Apparently this is a trending topic--I've seen other writers talking about similar things. I can tell you some of the differences. First, sugary, fatty treats were not everywhere, in every store. Food was purchased at a grocery store, candy was obtained only on major holidays. Drug stores were where you bought toiletries and greeting cards. Convenience stores were few and far between, as well as stand alone, not attached to every gas station. (Garages where cars were worked on were attached to gas stations.) Temptation didn't lurk on every side. We ate three meals a day, and had dessert only on Sunday. We didn't graze from morning until night. Most families had just one car, children and teens walked to school, or rode a bike or car pooled, or all three at various times. Computers were for NASA and huge businesses. Phone were attached to the walls of homes. Children and teens were outside playing or working. Physical education classes were still mandatory. More mothers were at home supervising their children, "Don't eat that you'll ruin your dinner!" Restaurant portion sizes were much smaller too. So many societal differences! It takes a strong constitution to resist all the temptations one encounters daily. The 70's were the beginning of huge changes with feminism encouraging women to leave home and enter the work force to find fulfillment. Divorce laws relaxed breaking up families. Food companies in quest of profits began to manufacture treats and snacks of every kind. We are now reaping the consequences of short sightedness.
Rozy, it's a problem in most Western countries. When I look at some youngsters I keep wondering what would happen if Heaven forbid, a war started. They'd have a heart attack from trying to run a 100m distance. No way they'd make it in the fox holes or wherever. Several years ago we went to Paris and I remember the shock I experienced upon coming back. Everybody seemed gigantic:) And yet, we aren't even doing that bad by European standards. The difference is, Frenchies still eat normal food, mostly, even in the capital.