You've hear that fast food is not healthy for you. In fact, it may be one of the reasons why scale is tipping in the wrong direction.
The fast food is not only the reason to blame. Exposure to a chemical in their wrappers can slow metabolism. Fast food wrappers contain the chemicals perfluoroalkyl substances, or PFASs. Research form Harvard’s School of Public Health has linked exposure to these substances to a decrease in metabolism, which can lead to weight gain.
PFASs are used in the wrappers to prevent grease from leaking out. According to the "Daily Mail," “The chemicals can permeate into the food… and are then ingested and absorbed into the bloodstream.” Qi Sun, the lead researcher on the project founds a “clear link” between exposure to the chemicals and a slower metabolism and warns that “every single person in the U.S. likely has a detectable level of PFASs in their blood.”
Source: Daily Mail