being a 7+ foot tall person seems dependent on genetic factors, but most people regardless of genetics seem to be able to hit 6+ if they have the right diet and activity in their developmental phase.
Diet high in proteins with lots of physical activity, sports, less junk food = tall kid
Epic gamer kid chugging mountain dew and eating potato chips and not much else = manlet.
many such cases!
of course we see this historically with early agriculturalists like the ancient egyptians being turbomanlets, while steppe hunter-gatherers whom also ate lots of meat like Proto-IEs got fuckign tall, just like the north plains fellas.
In short, if any of us manage to procreate (tall order), force your kid to play sports and eat meat and don't let them game too hard and don't let them eat fucking garbage.
Also they shouldn't smoke that probably stunts growth