Cottonseed was a disposal problem. Gins dumped it in rivers, until Procter & Gamble hardened the oil, called it Crisco and sold it as the modern answer to lard. Whey was a disposal problem. Cheesemakers poured it down drains and fed it to pigs, until somebody dried it, put it in a tub and sold it to gym members. Skimmed milk was a disposal problem. It was what remained when the cream went for butter. It went to the pigs too, until it got a red top and a health claim. Bran was a disposal problem. Millers bagged it as animal feed, until Kellogg's boxed it in 1916 and sold it as regularity. Rapeseed oil was a disposal problem. Its market was lubricating ships' engines, and that died in 1945. Canada bred out the worst of it, renamed it canola and called it heart-healthy. Defatted soya was a disposal problem. It was what the oil mills had left over, until it was textured, flavoured and sold as a burger. Beet pulp, citrus peel and oat hulls were disposal problems. They are now listed on the pack as added fibre. Every item on that list has been sold to you as a health food. Every item on that list began as something a factory was paying to get rid of. Your great-grandmother knew exactly what to do with all of it. She fed it to the pig and ate the pig. It made the pig fat, incidentally. Nobody thought that needed a study.

In 1939, a British doctor stood up in front of Singapore's businessmen and told them their tinned milk trade was killing babies, and that the deaths should be recorded as murder. Then she named the product. Cicely Williams had earned the right to say it the hard way. In the early 1930s, working in the Gold Coast, she kept seeing toddlers arrive at her clinic swollen, peeling and dying, always the same story: a new baby at home, and the older child moved off the breast and onto maize gruel. The local Ga mothers already had a name for it, kwashiorkor, the sickness of the child deposed by the next one. Williams worked out what it was: the gruel had no real protein in it. Take a growing child off milk and put him on a plant paste, and he falls apart from the inside. Her superior, a celebrated authority on tropical medicine, informed her she was wrong, that this was merely pellagra, already described, nothing new, and certainly nothing discovered by a junior woman. She published anyway, in The Lancet in 1935, and she was right, and it took the profession the better part of 2 decades to admit a condition that was killing children by the hundred thousand had been identified by the one doctor who actually sat with the mothers and asked what the child ate. Then Singapore, 1939, and the second fight. The shops of Malaya were stacked with sweetened condensed skimmed milk, sold with a fat, beaming white baby on the label, and mothers were being persuaded off the breast and onto it. Skimmed: the fat removed, and with it the vitamins, from the one food a baby cannot do without, sold to the poorest women in the empire as modern and superior. Williams watched the infants come in blind and dying, and delivered the speech that follows her name around: Milk and Murder. Misguided propaganda on infant feeding, she told the Rotary Club, should be punished as the most criminal form of sedition. The audience contained men who sold the stuff. She had checked the guest list first. Three years later the Japanese took Singapore. She spent the war in Changi, and 5 months of it in the hands of the Kempeitai, and came out at 6 stone, and went straight back to work. In 1948 the new World Health Organization made her its first head of maternal and child health. She died in 1992, at 98, having outlived nearly everyone who had corrected her. Her Singapore speech was dug out and reprinted in the 1970s, when the formula companies had moved from tins in Malaya to powder across Africa, and it lit the fuse under the Nestlé boycott and the 1981 marketing code the industry has been treading on ever since. She kept saying one thing for 60 years, and it is the whole argument: the animal food is the food. The baby needs milk and the child needs protein, real protein, and every fortune ever made steering mothers away from that fact was built on a mound of small graves. Turn today's formula tin round and read the ingredients. Seed oils, up near the top, in the first food of millions of children. She told a room full of salesmen what that trade was called. Nobody has ever improved on the word.

Germany killed a third of its pigs in the spring of 1915 because a committee had proved they were eating the people's bread, and then the people starved. The committee was chaired by Paul Eltzbacher, a law professor, and reported in December 1914. The sum was simple. A pig eats grain and potatoes. A man eats grain and potatoes. With the British blockade closing the sea and the Russian grain gone, every potato fed to a pig was a potato taken from a German. The report gave the animals a name that did the arguing for it: Mitesser. Co-eaters. The government had already fixed the price of potatoes so low that farmers were feeding them to the pigs rather than selling them at a loss, so the state banned that too. Then, from March 1915, it ordered the cull. The herd stood at about 25 million. By the summer it was down towards 17 million. Somewhere around 9 million animals killed in a few months, in a country with no cold chain to speak of, so the meat was salted, canned in wartime tin that leaked, and left to rot in warehouses. Whole trainloads went off. The pork that was supposed to feed the cities in 1916 had been eaten or thrown away by the autumn of 1915. The grain did not appear. The pig had been feeding on kitchen scraps, whey, chaff and spoiled potatoes that no human was going to eat, and the professors had counted all of it as bread. Then the ground gave out. The chemical works that had made Germany's nitrogen fertiliser had been turned over to explosives, and on the small farms of the Reich the manure heap was the only fertiliser left. The manure heap was the pigs. Yields fell through 1915 and 1916, the potato crop failed in the wet autumn of 1916, and the country went into the winter of 1916 to 1917 on swede. The Turnip Winter. The Imperial Health Office put an adult man's need at 3,000 calories a day; the ration delivered about 1,000. A Berlin physician reported 80,000 children dead of hunger in 1916 alone. Youth crime doubled as boys broke into barns. The kaiser's Germany did not lose the war on the Marne. It lost it in the queue for turnips, and the strikes and the mutinies of 1918 came out of that queue. The pig is the most efficient animal ever domesticated for turning what people will not eat into what they will. It lives on waste. It fertilises the field that feeds it. And it was the first thing a modern state decided it could do without, on the strength of a calculation that counted only what the animal took and nothing it gave. A committee with a spreadsheet, a herd measured as a cost, a country told the sacrifice was for the bread. Nobody in the room was lying. They simply did not know what a pig was for until they had killed it. The manure heap never came back in time. The Reich did not survive it.