Are Fast Food "Trans-Fat" Claims True? An Infraspec VFA-IR Spectrometer Analysis of Trans-Fat Content in Fast Food French Fried Potatoes


  • Sharron K. Jenkins Purdue University North Central
  • Patty Campbell Purdue University North Central
  • Lakiska Flippin Purdue University North Central
  • Nicole Helsel Purdue University North Central
  • Chelsea Sieradzki Purdue University North Central
  • Jose Haro Purdue University North Central
  • Bharathi Muthusamy Purdue University North Central


Fat, trans-fat, fast-food, fries, ATR-FTIR, Variable Filter Array Spectrometer, VFA-IR


Many U.S. fast food chains now claim that their food items, particularly French fries, have "no trans-fat". The purpose of this study is to assess the accuracy of fast food trans-fat labelling and the validity of "no trans-fat" claims. To accomplish this objective, we determined the percent trans-fat in oil extracted from fries obtained from 13 popular fast food restaurants and compared our findings with the percent trans-fat found in each restaurant's literature. French fry samples were purchased at relatively the same time of day on four separate days over two years from selected restaurants within Michigan City, Indiana. Variable Filter Array (VFA) IR spectroscopy was used to assess the trans-fat content of oil extracted from the samples. In June of 2008, seven of the thirteen restaurants sold French fries with trans-fat levels ranging from 13–43% of the total extracted fat. In most cases, these values were significantly higher than the amount of trans-fat reported in each restaurant's literature. Our study suggests that trans-fat content in fast food fries may be much higher than what is actually disclosed in a restaurant's literature. In addition, a restaurant's "no trans-fat" claims may not necessarily hold true for all the individual restaurants within its chain. Since there is no U.S. federal regulation of trans-fat content in fast foods, it is important that trans-fat claims and trans-fat labelling are accurate and up to date so that consumers are able to make healthy and informed food choices when dining in these establishments.