Carb-conscious Americans continued to flatten Krispy Kreme Doughnuts, as the onetime Wall Street darling yesterday posted a loss of $3 million in the third quarter. That bad news sent the stock reeling 16 percent — or to just above the $7 price of a dozen assorted sweet things. The struggling doughnut chain has lost more than 75 percent of its market value since last year as people have suddenly stayed away from the glazed treats in droves, and opted for healthier snacks. As a result, each Krispy Kreme store has seen $10,000 a week in revenue waddle out the...