A commercial made to raise awareness in a current social epidemic and to draw attention to those whom the author believe are most responsible in a bid to drive discussion and action to reverse the downward trend.
Anti-obesity campaign

JUNK= Rubbish, something of poor quality and little or no value, something harmful. In colloquial English "junk" is heroine (a junkie is a heroine consumer). JUNK FOOD is the same as "fast food". The most popular kind of junk food is hamburgers and chips, as you can have at McDonalds or Burger King, etc.