Much of the time fast food is looked upon as something to be avoided. It is not the healthiest lifestyle to actually eat fast food day after day or even a few times per week. For best health, having this food as rare as possible is seen as best. Even though there are some issues with it, there are also a variety of advantages to fast food today.
First of all, it saves so much time. For many people who have both parents in the house working, buying a meal that is already prepared, cooked, and ready to eat is the easy alternative to cooking yourself. Part of the price that is paid is for the time that it took to cook this food so that it is hot and ready when you come to pick it up. For those who are busy, this will tend to be an option to choose more often than not.
Certain foods are fairly cheap. If you like hamburgers, there are many on the $1 menu that would be hard to make at home for about the same price. Other dishes that you like might be difficult for you to make at home getting same deal on the foods just because the mass produced version can cut costs in places that you can't.
Today one huge advantage is that most fast food places have nutritional information. Getting fast food is not bad. Getting the wrong kind of fast food that is high in calories, sodium, and fats can be a problem. Many places who have been labeled as having unhealthy fast food over the past few years have improved the quality of the food. Just because it's fast does not mean that it has to be unhealthy anymore.
This is not to necessarily encourage you to always go out and get this food because there is quite a bit that is not healthy. But you can do so in a responsible manner getting foods and saving time.