By nature, green gram is light to digest. So, too, are meats of the quail and the grey-partridge. On the other hand, black gram is heavy to digest and so are the flesh of hog and buffalo.
In general, heaviness is the characteristic of males while lightness is the characteristic of females. Those that are massive in size in each class are heavy and those that are otherwise are light.
Heavy articles, it should be known, become lighter on preparation (or cooking) and the light ones become heavier just as rice becomes light when roasted and roasted corn flour becomes heavy when cooked and prepared into balls.