In my experience and from what I've gathered from others, bears use their amazing nose to discriminate between food and food smells.
While the smell of cooking on your clothing or gear might attract a bear to your site, they know that people don't harbor Ramen and powdered milk under their t-shirts. They will rustle through your pots if they are left out, but after a cursory sniff they can tell it isn't worth finishing the job your brillo pad started.
Bears use their noses to target the worthwhile stuff, much like a thru-hiker choosing between an AYCE buffet or a stick of sugar-free gum. To them it is an Easter egg hunt, using their smell radar to hunt down your densely packed high calorie goodie bag. They've got things to do and places to be, and will soon be on their way if your candy is locked away.
All bets are off with truly wild bears though. If they can't tell the difference between a bipedal hominid (or quadruped w/hiking sticks) and a trash can, they might feel the need to get a taste. Read some of the journals from folks who walked around Alaska and how bears ran at them to find out what they were.