U.S. stocks are heading lower on Tuesday amid renewed worries about the outlook for global growth. The price of oil fell, pushing energy stocks lower. Drugmakers also dropped, adding to their losses from Monday, when they plunged on concerns about new regulations. KEEPING SCORE: The Standard & Poor's 500 index dropped 23 points, or 1.1 percent, to 1,943 as of 10:13 a.m. Eastern. The Dow Jones industrial average fell 200 points, or 1.2 percent, to 16,308, and the Nasdaq composite dropped 67 points, or 1.4 percent, to 4,761. CANNED FOOD: ConAgra Foods tumbled 4 percent after posting a $1.2 billion quarterly loss. Sales for the maker of Chef Boyardee, Hebrew National hot dogs and other packaged food also fell short of analysts' forecasts. ConAgra's stock... More