My son at 7 currently is the size of an 11 year old, 4' 9" and 90+ pounds, needless to say he's the biggest kid by far in his grade even though he's one of the youngest. Docs think he'll be at least 6'7", it is insane, something in the food I guess and wow I didn't notice Iamred is back! welcome back ned..
It's not uncommon for we Americans to be taller than our immigrant parents. My father was 12 inches (30cm) taller than his mother and 6 inches (15cm) taller than his father, both from Scotland. I believe the difference is the extra vitamins, minerals, and fat in the diet. There is great variety in our diet whereas some countries have a very limited diet. How could you not grow taller eating two all beef patties, special sauce, lettuce, cheese, pickles, onions, on a sesame seed bun? Oh, I forgot, fries and a Coke, too.