Not at all, that is the simplistic silly way to look at it and it is simply not true. So many nutrients have so many functions that help you lose weight. The trouble with processed food is sodium.
Two examples i will use quickly, sodium which is found in all processed food causes bloating because the cells in your tummy i think cannot absorb the water so the answer for that is cutting down on sodium and introducing potassium, potassium helps the cells absorb water which makes you less bloated and less fat looking

. Now if we went according to your way of thinking we would still be bloated even though we exercised all the kfc off.
Grapefruit is a documented fat fighter, studies have shown that eating it before a meal will help you lose weight(without exercise).I will copy and paste later what fruit does what as i have the memory of a fish but the basic idea is eat fresh fruit and eat a lot of it if you want to lose weight, obviously i am not talking 20 oranges and 20 or 30 apples but a couple banana's, avo's, tomato basically fresh produce will make you lose weight more than exercise and a poor diet but as soon as i am home i will copy and paste some of my bookmarks.