By Medha Singh (Reuters) -Shares of U.S. grocers, packaged food companies and supermarkets were lagging in the first three weeks of 2023, in a sharp contrast to last year, as their high valuations and fading dividend appeal pushed investors to U.S. Treasuries. The S&P 500 consumer staple sector, along with other bond proxies including real estate and utilities, outperformed the broader market in 2022 amid recession fears, as investors sought shelter in dividend-paying companies. In a reversal of the trend, consumer staples sector has shed 3.4% in 2023, the most among the major S&P sectors, whi…