Fast food is any food that is quick，convenient and usually inexpensive ．Vending(出售)machines are probably the most common places to find fast food．It's so popular because for under$5.00 you can usually get a meal．Fast food is not expensive because it is usually made with cheaper food such as high fat meat and high sugar food．There is not enough fresh fruit or vegetables in it．

    It's true that fast food is bad for us．If you eat too much fast food over a long period of time，it can lead to health problems．

    Don't eat too much fast food．