The latest warnings came from two packaged-food giants on Thursday, PepsiCo and Conagra Brands. Pepsi said sales volumes fell 4% from a year earlier in its Frito-Lay North America business and 3% for North America beverages in its fiscal second quarter ended June 15. Thanks to higher prices, revenue was down just 0.5% for Frito-Lay North America and up 1% for North America beverages.