I have a 4 week old baby who is mainly breastfed - occasional (eg twice a week) formula top ups. He was 2.8kg at birth and last week was 3kg, but I get the impression they were hoping for him to have put on a bit more. Someone told me the charts they use (in the red book) are based on formula fed babies who grow faster: does anyone know if this is true? Baby is filling lots of nappies and has plenty of energy for demanding food/thrashing about when unhappy so I feel he's doing fine but I have to take him to be weighed again tomorrow and am worried he might not fit the graph...