MILAN (AP) — The only woman to have been the first lady of two countries said Saturday during an international nutrition summit held in Italy that a major challenge in making the eradication of malnutrition a global priority is that the problem "is a hidden pandemic."

"It is not visible in daily life," Graca Machel, a campaigner for the rights of women and girls and the widow of both Mozambican President Samora Machel and South African President Nelson Mandela, said at the meeting in Milan.

Organizers of the summit announced $640 million in new commitments to tackle global malnutrition, bringing pledges over the next decade to $3.4 billion. The meeting brought together national government representatives, foundations and non-governmental agencies.

The funds go toward a range of programs that support the United Nations' goals of zero hunger and malnutrition by 2030 and targets the World Health Organization has set for 2025 — reducing stunted growth in children under the age of 5 by 40 percent and reducing anemia in women of childbearing age by 50 percent.

Still, the sum collected under the summit auspices can be seen as just a down payment on the $3.7 billion a year the World Bank says is needed to make progress toward the global targets.

Malnutrition is an underlying cause of half of child deaths worldwide, according to a report commissioned for the meeting and based on data from UNICEF, WHO and the World Bank. Some 155 million children globally suffer physical and cognitive impairments from being malnourished, the report said,

Still, Machel says progress is being made.

"For many years, nutrition was seen as something which belonged to health. Now, it is being viewed at the center of development" and moving up as a governmental priority, she said.

Former U.N. Secretary-General Kofi Annan concurred.

"Governments are realizing that malnutrition affects the economic bottom line," Annan said in an interview. "They are realizing it pushes up health bills. "

Annan's own foundation is trying to tackle malnutrition in his native Ghana by working with small-scale farmers and promoting orange flesh sweet potatoes as a source of Vitamin A to prevent stunted growth.

"If we tackle malnutrition effectively, we will be improving the general health of the population," he said. "We will be preparing young kids who are able to take advantage of the education."

Machel also has a foundation that focuses on Pan-African advocacy, especially in the areas of child health, nutrition, and the economic empowerment of women. Progress on reducing malnutrition has been made in such countries as Nigeria, Niger, Tanzania and Rwanda, where governments are funding nutrition programs, she said.

Presenting governments with research demonstrating the importance of nutrition to children's mental and physical development, particularly in the first 1,000 days of life, but also during other critical stages such as adolescence and pregnancy, has proven an effective tool, Machel said.

"It is not that governments are insensitive," she said. "Once this is clear to them, they will understand that as much as it is important to have resources for education, if we have not tackled nutrition, particularly in the first 1,000 days, it is a bit late because this child will never reach the full potential."