快食 is wrong. "Fast food" is equal to “快餐". for example supper = 晚餐 not 晚食 lunch= 午餐 not 午食 breakfast= 早餐 not 早食.

actually it's 快餐. we don't say 快食=) (you mean the food like hamburger and french fries right?)

we don't say 快食 ! we called the food like hamburger and french fries as 快餐！ 食 is food It is means something which we can eat! 餐 is meal They are very similar in implication！But we say 快餐 not 快食。

Just as a side note, "快餐" doesn't ONLY mean McDonalds, etc. It can mean any food that is fast, including Chinese food. I have seen many restaurants in China which offer Chinese "快餐".

is 快餐 like McDonald's and KFC's food.