A U.S. federal advisory panel says more study is needed into an alleged link between artificial food dyes and hyperactivity in children.

The panel said Thursday there is not enough evidence at this time to call for a ban.  It will send its recommendation to the Food and Drug Administration.

Some consumer groups have called for a ban on artificial colors in food.  They say the colors serve no purpose but cause hyperactivity and attention problems in children.

The panel Thursday heard testimony from a mother who said her once hyperactive son who had poor grades in school became a different child when she removed artificial colors from his diet.

Food companies use the coloring to make products more appealing on the plate and more attractive to consumers on store shelves. They say a link between the dyes and health problems in children has never been proven.