Fast Food places don't make you buy or eat the food. That is your own choice. You could look at the calories and decide how much you should eat and if you keep stuffing you face with junk food that is YOUR OWN FAULT!!!!!!!!! Make better decisions in life...Don't kill yourself...
They provide a service that specifically targets people too uneducated, or too poor, or too much in a hurry to be capable of choosing otherwise.
The people with the money to eat better food usually do so unless they are too uneducated, and the ones not in a hurry in life, rushing to or from work (possibly multiple jobs to feed a family as a single parent), have the time to purchase better quality food. Often being able to cook with fresh ingredients.
In our nation, we are incredibly busy. We are always in a hurry, and we barely have time for much else but work and resting at home. The fast food industry takes advantage of that.
If we imagine a thought experiment where our civilization was identical to what it is now, but without the fast food, would we have much less obese individuals? Possibly. But we must remember that the vast majority of meals given to children (which in turns trains them towards what sort of food they will want to eat as they mature), the food comes from grocers in prepackaged bags or boxes.
"Cereal" that is basically candy in a box fed to children, fattening breaded "chicken" nuggets on par with fast food, chips of a thousand varieties, nearly every food sold in stores is prepared in the same way as fast food is, stuffed full of fat, grease, and sodium, in order to make it as delicious as possible.
But fast food chains only provide a slightly more convenient method of obtaining this fattening food.
People still get the majority of their unhealthy food from the grocery stores instead of walking down two isles and picking up fresh ingredients and cooking for themselves.
Without fast food, people will still be fat. Our nation is besieged on multiple fronts to be unhealthy. Fast food is only the most obvious attacker.
Technically yes because of how much fat is in their food, and how much people eat the food. Technically no because it's a person's own choice, if they want to eat at a fast food place. The fast food places themselves aren't responsible for that other than the fact that they exist.
Of course fast food may offer you a convenient way to eat filling, carb-loaded food for a very small amount of money; and thus is greatly appealing in that regard, however we must be honest with ourselves. The fast food chains are still in business beyond all they have been exposed for due to one reason: we keep buying it. While I do personally believe that fast food chains make an effort to sell their products through means both psychological and flat out blatant, it is still our choice to purchase their product. They blast us with advertisements, particpate in shady business practices; such as Taco Hell's horsemeat incident, and feed us the lowest possible quality of food with no nutritional value, but we are the ones who line up to hand them our money. I am in no way casting spurs at the obese or those who have had health complications due to eating fast food. I can only speak from experience when I say that the only reason I make the decision to go by Taco Bell for dinner is because I'm too lazy or impatient to cook, go to the market, or wait any longer to eat. If some day my decisions bring obesity upon me, it will be my responsibility.