Is it possible to lose weight by walking/ jogging 4 miles a day. i keep reading articles saying you do not.

Depends: That is excellent exercise especially if you did 2 miles twice a day. If you combine that with 6 healthy meals, a good night sleep, and stress reduction and persist at it you certainly are likely to lose weight and gain muscle. Read kelly mcgonigal's the will power instinct, 2012 to increase your ability to stay on a healthy path.

Yes: Activity along with a healthy diet is how you should approach weight loss. 4 miles would be a good amount of activity; I have no idea what articles would say that would not contribute to weight loss.