If one of their men grows to 1.40 meters or 4 feet 7 inches, he would be considered very, very tall, they have not been known to grow taller than 1.45 m or 4 feet 9 inches, beating even African pygmies by about a hand width.
Why they are this short is not completely clear up until now, but it seems that it has to do with their diet which consists mostly of sweet potatoes and other plant material.
Animal protein, while not completely absent (they keep pigs), is quite rare, which may contribute to their stature.
This theory, however, stands on rather shaky legs, it seems reasonable to assume that higher altitudes just provide less food than the lower areas.
All that being the case, the Kimyal are however observed to be growing.