I'll answer for me and not try to answer for people in general. People's metabolisms are different, different food works for them.

Empirical answer: different sensation basically the minute it enters my body, from refined sugar. I don't enjoy that feeling it and I could feel it in a blind test. My body and brain do not feel good on such sugars, and avoiding them entirely is a good way to remove the craving for them.

Scientific answer: fruit sugars are slower to take up than refined sugars, when delivered in as juice or in fruit.