My mom would seriously refute this study. When I was growing up, my sugar was very much limited except for dessert after meals because of the effects on my behavior which were directly observed by her. I was a pretty hyper kid to begin with but would be bouncing off the walls if I had a sugary snack or lots of candy. Note that fruit juice and the like was not a problem for me, just the white stuff. I have experienced the same thing while babysitting. I’m sure it doesn’t affect all kids, but it surely effects many, despite whatever this researcher based his findings on (probably a small subset of behaviors).
One clue is that the study cited only compared sugar with saccharine and aspartame. Aspartame probably has a worse effect on children’s behavior than sugar. It’s a neurotoxin. That alone pretty much de-legitimizes the study.