The effect that chocolate can have on children's behavior is still being examined by scientists, as the common perception linking sugar consumption to hyperactivity.

"If you look at the peer-reviewed evidence, we cannot say sugar absolutely makes kids hyper; however, you can't discount that sugar may have a slight effect" on behavior, senior pediatric dietitian at Texas Children's Hospital and spokeswoman for the Academy of Nutrition and Dietetics, Kristi L. King, said.

A study in the mid 90’s published in the medical journal JAMA noted that sugar does not affect behavior or cognitive performance in children, but that children with attention-deficit hyperactivity disorder may be extra sensitive to sugar.

"They may become more aggressive or hyperactive or difficult to parent," Jill Castle, a registered dietitian and childhood nutrition expert who teaches a parenting course called the ADHD Diet for Kids Castle explained. "Minimizing sugar in the diet can be beneficial for these children."

"When children consume sugar, it's usually around something fun: holidays, birthdays, celebrations; there's already that excitement there. I don't think you can say the sugar made them run around and play with friends. ... That would be very hard to separate out,” King said as assessing another study.

"It's a flight or flight hormone; when you are excited or fearful, it increases heart rate and directs blood flow to the muscles, which may make children more antsy and have the urge to keep moving, so you may be perceiving that as hyperactivity," King added.

The American Heart Association recommends that children, aged between 2 and 18, consume less than 6 teaspoons (24 grams) of added sugars daily.