] Height, while determined largely by genetics, also is
] influenced by childhood nutrition. Adults in the early
] 1960s grew up during tougher times when they may not have
] had enough to eat, Klein said.

Is this really the cause? I find it hard to beleive that baby boomers had slim pickings at the dinner table in the 50's.

Yahoo! News - Americans Getting Taller, Much Heavier