I remember homemade cookies and a glass of milk after school, and we always had some kind of desert about an hour after dinner, sometimes ice cream, or cake made from a box mix, sometimes pie for special occasions. In junior high and high school we could buy ice cream cups or bars,, cookies and other snack items from the student store. If we had enough money we would buy a coke at the store on the way home from school, or an ice cream bar at the ice cream truck parked by a side road on the way home from school, or french fries and a coke from McDonald's (new when I was in high school in late 1960's.)
Obviously we had a lot of snacks and we never felt guilty about it. I still weighed under 100lbs when I graduated from high school in 1969. We were active, (not athletic really), but walked to and from schools, rode our bicycles, roller skated on sidewalks, went to roller rinks for fun, played outside games or hide and go seek in our neighborhoods, walked long distances to visit a friend or go to an outdoor mall. I believe the closest mall was over 2 miles each way. We went to the beach and body surfed all day, in between walking around and checking out the boys, eating hamburgers, french fries, candy, ice cream cones, donuts, salt water taffy just made at the candy store. I don't remember anyone being fat, maybe l out of 50 kids was overweight.