The packet lunch

In this unit I learned thinks about a packet lunch, this is an example:

Most schools in Britain provide hot meals and salads every day but many students prefer to take their own lunch to school.
A lot of chocolate, crisps, fatty foods and cola isn't good for people. But these foods are everyhere.
Their use a lunchbox.
Green machines have got lots of interesting snacks. There are cereal bars, organic crisps, yogurts, and the drinks in Green Machines are healthy as well.
The British Government is worried that many children are obese.