Eating chestnuts in autumn benefits kidney and qi. It is suitable for eating something warm after Frost's Descent. The chestnuts are sweet and warm, and they can tonify kidney, benefit qi, nourish stomach, invigorate spleen and so on. So it is the most suitable for eating in the last autumn and the early winter. Yam is also a good tonic in autumn and winter and it helps spleen and stomach digestion functions. This kind of soup is most suitable for tonic in autumn and winter, because it can invigorate spleen and nourish stomach. And it is tonic delicacy which is especially suitable for