饮食习惯（the eating patterns）
　　eating patterns change over time. ingredients cannot be seen before in a country might begin to appear in local markets ， shipped from abroad. migration causes cultures to change， and eating patterns invariably reflect new influences.
　　in the 20th century， few people have the time to go home for lunch， and many city dwellers find themselves in need of grabbing a bite to eat in a place close to their offices. as a result， the popularity of fast food and takeaway food has risen . in many urban areas， people who traditionally ate their main meal at midday now enjoy it in the evening， after work.
　　changing eating patterns have an effect on other aspects of society. meals have traditionally been times when members of a family catch up with each other. fast food and quick meals sometimes threaten such family get-together.