A ten bedroom house has to be occupied by ten couples. The ten keys of the ten bedrooms are in one single key chain. Naturally the bedrooms will have to be opened one by one.
If the keys to ten bedrooms were in ten different keychains then time taken by ten couples will be very less.
If I extrapolate this to sugars then the sugar in starch/fruits is like ten keys in one key chain. Body will gradually break down and use sugar as per requirement.
Refined sugar is like ten different key chains. The moment it reaches in stomach, 100% is absorbed into blood resulting high sugar levels.
Sugar in fruits/starch is complex and good. Refined sugar is simple and BAD.