A、Because one in four children is dying from poor nutrition. B、Because more than half of child death is caused by poor nutrition

A new report from the United Nations says the world must do much more to reduce the number of underweight children. It says one in four children under the age of five is seriously underweight.
Poor nutrition is linked to more than half of all child deaths. Experts say it is a cause in more than 5.5 million deaths each year in children under five years old. The United Nations Children’s Fund, UNICEF, published the report last week. The report measures progress toward reaching the first Development Goal of this century: reducing extreme poverty and hunger. In 2000, world leaders approved a list of eight goals to reach within 15 years. The aim is to improve the lives of the world’s poor.
UNICEF says China has already met the target of a 50 percent reduction in the number of underweight children. It says China has cut the rate from 19 percent to 8 percent. A growing economy and government efforts to reduce poverty and improve nutrition are given credit. But UNICEF says at current rates, the goal of cutting poor nutrition in half world- wide will not be met. It says rates of underweight children in developing countries have dropped by just 5 percentage points since 1990.
The head of UNICEF, Ann Veneman, says nutrition affects life at every point of development, starting before a child is even born. But she says too many people do not know about its importance, and how serious a problem there is around the world.
Why does the UN call for the reduction of the number of underweight children?