Myth: Sugar makes kids hyper.
Truth: Sorry. No matter what you've observed in your own or other children, there is no scientific evidence to support this belief.
So why the dichotomy between what research shows and what parents observe? That's because sugar itself isn't the culprit, says Alan Greene, M.D., a pediatrician in Palo Alto, California. Any food that affects blood-sugar levels (a tomato as well as a candy bar) can create an adrenaline surge, which may lead to a burst of energy. That effect is usually mitigated by fiber, which helps pipe everything into the bloodstream at a steady pace. However, many sugary treats are low in fiber, and it's that fact that explains the energy burst -- not the sugar itself.
So if adrenaline rushes are a constant in your home, push the apple over the apple juice, and know that it's okay for your child to add sugar to his breakfast cereal -- as long as it's a high-fiber variety.