Growing up, Saturday night was pizza night (which half of the time we made ourselves, the other half was split between frozen or take-out), and starting when I was 10 or 12, we got to ration 2 sodas for the weekend.
McDonald's was reserved for special occasions or long shopping trips (so once about every 2-3 weeks).
But, I ate PB&Js like crazy matched only by the gallons of milk to down them. Grape juice and apple cider ran through my veins as much as milk did. And, I swear my brother and I would just split a box of cereal every morning, using mixing bowls instead of regular bowls.
However, I played outside by myself or with neighbor kids every nice day, and I played soccer from the age of 5 up to high school. I was always in very good shape.
Now, my nephews get winded climbing stairs.