UNITED NATIONS -- Sub-Saharan Africa's economic surge could be threatened in the decades ahead by food shortages there that still affect nearly a quarter of the population, the U.N. Development Programme cautioned in a report.

UNDP, in a paper released as the "Africa Human Development Report 2012," warns that growing gross domestic product rates in much of Africa have not translated into food security for all. The agency goes on to argue for decisive action.

Among the approaches the agency wants to promote are more agricultural productivity, more subsidies for seed and fertilizer, and fair treatment of women looking to farm or enhance farming techniques.

"Inclusive growth and people-centred approaches to food security are needed," said Helen Clark, the UNDP administrator, at a news conference yesterday in Nairobi, Kenya, to announce the report.

The report points to two examples -- Ghana and Malawi -- of countries in sub-Saharan Africa that have eased malnutrition and hunger by boosting output and subsidizing planting. Ghana was the first country in that part of Africa to meet Millennium Development Goal 1 on halving hunger by 2015, "partly by focusing on policies which encouraged cocoa farmers to boost output," the report says.

Sub-Saharan Africa is defined as the rest of Africa below the Sahara outside North Africa, which is considered Arab. The United Nations also classifies Sudan and South Sudan as Arab nations.

Drought insurance helps

During the news briefing, Tegegnework Gettu, director of UNDP's Africa Bureau, said Africa has food surpluses but lacks the logistics and infrastructure to avoid hunger in its most vulnerable areas. The report said more than 15 million people are at risk in the Sahel region across the middle of Africa from Senegal to Chad. The Horn of Africa (comprising Ethiopia, Kenya and Somalia) is also at risk.

Part of the problem is political instability. The report notes that areas fraught with civil conflict or vulnerable to disasters are less likely to be food secure, and climate change was also identified as a pressure point because of floods and droughts.

The agency recommends social protection programs such as crop insurance, employment guarantee schemes and cash transfers, "all of which can shield people from these risks and boost incomes," the report says.

Kenya, for example, has a drought insurance program that is unique to Africa, according to UNDP. It pays small farmers based on rainfall levels and protects them during droughts.

The report suggests the food problem could deflate Africa's steady economic rise because a population boom is expected by midcentury. According to The Economist, over the past decade, six of the world's 10 fastest-growing countries were African.

In eight of the past 10 years, Africa has grown faster than East Asia, including Japan, the magazine said. The International Monetary Fund expects Africa to grow by about 6 percent in 2012, roughly equal to Asia.