Nice to meet you
Since You mentioned " Eat junk food every day" I suspect you already know about the term "empty calories". If not -
http://www.mahler-chiropractic.com/uplo ... 757577.pdf. is a good place to start.
Most agri-business profits are tied to processed food. The sad truth is that they are more than willing to sacrifice your waist-line, to improve their bottom line.
They make their processed and junk food easy to access, appealing, and cheap. That's why lot's of people consume massive amounts of it. Still the body is still looking for the nutrition that it's not getting, so it sends the 'not full signal' and the feeding cycle continues.