Our great-grandparents, Pollan and others have argued, didn’t raise their kids on guar gum, soy lecithin, and many of the other ingredients common in today’s processed foods. They served milk fresh from the cow, turnips dug fresh from the garden, and cooked almost everything from scratch. If only we had stuck to this small-scale agrarian lifestyle, our kids would never spill Go-GURT in the backseat or bug us to refill their snack cups with ever more Goldfish crackers. The underlying claim is that if we ate this way, nobody would be fat.