Where there's spice, there's a loyal shopper. New understanding about how people who love spicy foods eat-and shop-is fueling the latest wave in making packaged foods hotter. "You get endorphins when you eat something really spicy," which feels adventurous to flavor-seeking eaters, says Krista Lorio, senior manager of consumer insights for General Mills Inc., which owns Cheerios, Betty Crocker and other brands.