All of this aid and help is supposed to foster better relations between the Unites States and developing countries. Instead of sending you vaccines and food let's send you contraceptives. A high population does not mean poverty. Japan has one of the densest populations on the face of the Earth and they are certainly not poverty stricken. In fact, many speculate that Japan's economic crisis are caused by not enough young people to drive the work force.
Policies are in place that actually bribe women to have children.
The problem is not one of overpopulation but of an economic division. If Bill Gates really cared about helping these people he would build factories in third world countries and have the profits go back into the third world countries instead of into the pockets of white American CEO's.