The fast food service Mcdonalds has many calories because all they sell there is just burgers, fries, sodas, and pies. Those foods are unhealthy and considered to be junk food with all that grease people like, the grease and fried food is what makes people fat since it got so many unhealthy calories. Some meals on their like the oatmeal and lettuce Mcwrap may be healthy but most of their food is unhealthy because the more calories it has, the more good it tastes so it brings in customers like a fisherman brings fish but instead of a scam, its just not giving your body what it really needs.
Mc Donald's has so many calories because of the ingredients used to make the food, with so many calories and people eating them not knowing what it what it does and what it can do. The more people eat all of these things, it can sometimes make you go over weight (not trying to offend any body, just saying) and the calories and ingredients put inside this food which is already made and shipped to state or country then to the restaurant, they there just warm up the food by cooking it and selling it customers. What makes customers/people want more of this food is because when the food is made, the make some type of drug to put inside the food to make it taste so good that you just want more and more.
