I do not know the thresholds at which added sugar becomes detrimental. That limit probably varies wildly with other conditions such as exercise and intake of ot

I do not know the thresholds at which added sugar becomes detrimental. That limit probably varies wildly with other conditions such as exercise and intake of other nutrients. However, I do know that added sugar is not necessary for a healthy diet. So you don't have an upper limit, but you do have a lower one!