Famine fucked up our statistics. The west have just started to catch up with injected growth hormone food. But in all honesty the tallest in the world are an african Dinka tribe that are 6'5 on average with no genetically modified food or western diet. Imagine how tall the dinak would be with western genetically modified food if they reach 6'5 on avergae with milk and hilib.
They'd be giants like in the old days.