Most researchers have attributed this to dietary and cultural changes that come from settling down.Both men and women began eating more starchy grains, such as corn and wheat, which contain sugars.

• 大多数学者将之归诸于定居后出现的饮食和文化变化：不论男女都开始进食更多的淀粉类谷物，比如玉米和小麦，它们均含有糖分。