Adds details on results, background, profit July 14 (Reuters) - Conagra Brands Inc CAG.N missed Wall Street estimates for quarterly sales on Thursday, with demand for its frozen foods and ready-to-eat meals slowing as it raised product prices. As decades-high inflation pinches spending at American households, top retailers have warned that more consumers are turning to cheaper private-label products, hurting demand at Conagra. Lingering supply chain issues and soaring freight and ingredient costs have also eaten into Conagra's profit margins, which have shrunk despite multiple rounds of price hikes over the past year.