According to the IITA, Africa imports about 1.5 million tons of soybean a year.  Let’s say that Trump’s trade war with China has been the reason that soybean prices have fallen from $10 a bushel to $7.50 a bushel over the last year or two.  There are 36 bushels in a ton so African countries are saving $2.5 x 54 m bushels = $135 million each year. Not enough to change consumption or nutrition very much unless there is a huge import surge. of course, we must also remember that soybean has been a rapidly growing crop in many production regions in Africa, and a price slump could slow that growth, and the consequently the externalities that come from developing the export market and the processing market.