Please remember, that you have many various types of bodies here, there are pygmies who are 4 feet tall, and there are tribes with 8 foot guys (Manut Bol, etc), and then you have in betweeners, and you have Urkel types as well. Africa is a huge place, and frankly they are going to adapt to their environment as all humans do over thousands of years.
We also had preferential breeding being done here during the slave trade years, take the big women and sometimes only 1 big male who's sole job as slave would be to impregnate other women, I'm sure I can find at least one story of this kind in some history books I have.
Overall however they do have higher test levels than whites, and people of the orient are usually on the bottom of the scale. Thats just how things go, people are different in all kinds of ways, BFD. I'm white, and not genetically predispositioned to carry tons of muscle, not that wide etc, but am happy that I at least didn't end up short as so many people local to me seem to be, so overall find a way to be happy with what you've got and just work with it.