Americans eat a lot of junk food
Different countries always assume that Americans eat a lot of junk food.
It might be because of all the famous American fast food chains such as McDonald's, Burger King, KFC, and so many more that are around the world that people from different nationalities assume this.
Nevertheless, these businesses seem to thrive regardless of this assumption throughout the whole world.
The question is: do Americans really eat a lot of junk food?

My observations:
My host family in Winter Garden, would buy Healthy Choice frozen dinners, since they are very busy people and do not have time to cook a home meal every day.
This may sound healthy, but when they don't have frozen dinners, they order pizza, Chinese food, Jamaican food, American food and so many other junk food for dinner.
They would have sandwiches for lunch, which mostly contained Turkey meat, ham, cheese, lettuce and tomato.
Breakfast was also pretty healthy most of the time. We would have cereal or oat meal.
However, the family loved to get junk food when possible.
My neighbors were the opposites of that. They told me that they try to stay healthy by eating low-calorie meals throughout the day. They would eat salads, wraps and so many other healthy meals. They would avoid going to the typical fast food restaurants that surround their area. They once told me that Americans don't need to eat unhealthy food, it's just that it's the quickest and cheapest thing around.
In conclusion, it depends on the family's eating habits and not necessarily the fact that they're Americans that determine whether or not they eat a lot of junk food.

Research:
After my own observations, I researched why people eat so much junk food in America and how many times they actually eat junk food.
I found a very useful website, the Pew Research Center's website, which has several polls on this issue. One poll, which is displayed above, is of a survey that was conducted in 2005. This research showed why Americans eat a lot of junk food. The highest percentage, 73%, showed that Americans eat a lot of junk food because it is convenient.
I can understand this especially since my host family showed me how convenient is was on several occasions.
One day my host family weren't home and I was hungry at home with no dinner. I called my host mother and asked her for dinner. And 15 minutes after that call, the doorbell rang. I opened the door and there was a delivery boy with an already-paid for pizza in his hands. Situations like that one makes the fast food industry keep going and keep getting more profit every day.

The Pew Research Center also has a poll which asked Americans how many times a week they dine at a fast food restaurant. The percentages are shown on the right side of each category.
I was shocked when I saw that in 2006, 41 percent of all adults eat at a fast food restaurant at least weekly.
In conclusion: Americans do seem to eat a lot of junk food and especially from fast food restaurants. The most important reason is that it's convenient.

Source:
http://pewresearch.org/pubs/?ChartID=90
http://pewresearch.org/pubs/309/eating-more-enjoying-less