Question

what is junk food in simple lines

Answer 1

Junk food is a pejorative term for food containing high levels of calories from sugar or fat with little fibre, protein, vitamins or minerals.

Answer 2

Junk food is a pejorative term for food containing a large number of calories from sugar or fat with little fibre, protein, vitamins or minerals. The term can also refer to high protein food like meat prepared with saturated fat