Some people claim that sugar (such as sucrose), aspartame (NutraSweet), and artificial flavors and colors cause hyperactivity and other behavior problems in children. Some people argue that children should follow special diets that limit the amount of sugar, flavorings, or colors they eat.
It is important to remember that activity levels in children vary with their age. A 2 year old is usually more active, and has a shorter attention span, than a 10 year old. A child's attention level also will vary depending on his or her interest in an activity. The tolerance level of the supervising adult also plays a role -- parents may be able to tolerate a highly active child at a playground in the morning, for example, better than they can at home late at night.
However, if a special diet of foods without artificial flavors or colors works for a child, it may be because that family has begun to interact with each other differently when they are following the special diet. These behavioral changes, not the diet itself, may improve the child's own behavior and activity level.
Refined (processed) sugars may have some effect on children's activity. Because refined sugars and carbohydrates enter the bloodstream quickly, they produce rapid fluctuations in blood glucose levels. This might trigger adrenaline and make a child more active. Sometimes, falling adrenaline levels bring on a period of decreased activity.
A number of studies have shown a relationship between artificial colorings and hyperactivity. On the other hand, some studies do not show any effect of colorings on children's behavior. At least for now, the effect of food colorings remains another controversial issue.