One Doc told us that short fat people had better G tolerance (distance from heart and higher base heart rate), also smoking increased the number of red blood cells and therefore helped in decompression situations (more oxygen stored in blood).
Then again, they only needed us to last to 55th birthday plus one day!!
That said I'm 6 foot and still weigh the 67 kilos when I marched (shambolically) across the parade square at Sleaford Tec.