Economic activity in the U.S. decreased by much more than previously estimated in the first quarter of 2014, according to a report released by the Commerce Department on Wednesday. The report showed that U.S. gross domestic product plunged by 2.9 percent in the first quarter compared to the previously estimated 1.0 percent drop. Economists had expected the revised data to show a 1.8 percent decrease. With the downward revision, the sharp drop in first quarter GDP represents the worst quarterly performance since the 5.4 percent decrease seen in the first quarter of 2009. The Commerce Department said the much steeper than previously estimated drop partly reflected a downward revision to consumer spending. The report said consumer spending increased by just 1.0 percent in the quarter compared to the previously reported 3.1 percent jump. Peter Boockvar, managing director at the Lindsey Group, said, "The biggest swing factor within spending that was revised much lower was the calculation of health care spending and the impact of Obamacare." "The statisticians originally expected a sharp increase in healthcare related spending in response to the March sign up deadline in addition to increased usage for those that have signed up and that today didn't come to the fruition that was expected," he added. Trade was also a bigger than expected drag, reflecting a downward revision to exports and an upward revision to imports, which are a subtraction in the calculation of GDP. The revised drop in GDP in the first quarter reflects a substantial turnaround from the 2.6 percent growth seen in the fourth quarter of 2013. The Commerce Department said the pullback primarily reflected a downturn in exports, a larger decrease in private inventory investment, a deceleration in consumer spending, and downturns in non-residential fixed investment and state and local government spending. However, Paul Dales, Senior U.S. Economist at Capital Economics, noted that "more up-to-date data show that activity is rebounding in the second quarter." "In short, the larger contraction in GDP in the first quarter is not a sign that the U.S. is suffering from a fundamental slowdown - it was still largely due to the extreme weather," Dales said. "The latest data are consistent with growth in the second quarter rebounding to at least 3.0%." On the inflation front, the Commerce Department said its reading on core consumer prices, which exclude food and energy prices, rose by 1.2 percent in the first quarter compared to the 1.3 percent growth seen in the fourth quarter.