For now , the US government 's `` Food and Drug Administration '' has allowed makers of food products to label their products as having `` 0 grams of trans fat per serving '' as long as the amount of trans fat in the food product falls below 0.5 grams per serving . However , unlike in many other countries , trans fat levels of less than 0.5 grams per serving can be listed as 0 grams trans fat on the food label .