DAKAR, Senegal — Nearly every year, the West African desert nation of Niger faces a food crisis, and nearly every year the international aid agencies, including the United Nations, send out urgent appeals for funds to feed the country’s starving millions. This year is no different. Niger, where women pick bitter green berries off scrubby trees to stave off starvation, cannot feed itself.

That unchanging reality is buttressed by another one, equally stubborn and deeply frustrating to demographers. With an average of nearly eight children per woman, Niger, by some measures the poorest country in the world, also has its highest birthrate. At current rates, the population will double in the next 15 years, to 35 million from over 17 million.

Does that make sense for a country that is perennially on the brink of mass hunger — one that is far from having the resources to feed its current population, let alone one twice as big? Obviously not, say the demographers. And yet precious little is being done about it, they say. A lack of commitment by aid agencies and officials to family planning means that birthrates and contraceptive use are hardly budging.

Elaborate plans have been drawn up over the years, but little has changed, said Jean-Pierre Guengant, an emeritus research demographer at the Sorbonne in Paris who has specialized in the Sahel region for many years.