The product may not look like much — a little foil packet filled with a soft, sticky substance — but its advocates are prone to use the language of magic and wonders. What is Plumpy’nut? Sound it out, and you get the idea: it’s an edible paste made of peanuts, packed with calories and vitamins, that is specially formulated to renourish starving children. Since its widespread introduction five years ago, it has been credited with significantly lowering mortality rates during famines in Africa.