Please send us the reference document. Our news editors use multiple sources before presenting the info. Coffee generally can cause children to become hyperactive. The statement of The National Institute of Health on coffee "a child's caffeine consumption should be closely monitored. Although caffeine is safe to consume in moderation, it may negatively affect a child's nutrition. Caffeinated beverages may be replacing nutrient-dense foods such as milk. A child may also eat less because caffeine acts as an appetite suppressant. Caffeine can be completely restricted in a child's diet since there is no nutritional requirement for it. This may be necessary for a hyperactive child as caffeine is a stimulant." Hence there is a negative impact of this substance.