Answer:
They are most likely to be advertised as "healthy" either to sell more of that specific item that they have on their menu or to convince people that they are eating healthier so they would come back to that fast food more often. I think this is very bad advertisement because if you clame your food as "healthy" and all it has is carbs, fat, and sugar then it's making us more unhealthy so always check what you are eating and the ingredients that are in your food before they are labeled as "healthy" online.