My daughter is 3’5" at 40 pounds. She is 75% in both height and weight. She is not overweight or chubby at all. Her legs and arms are very muscular. She is strong, active and well coordinated. Her leg muscles are defined! Her friend who is 5 does weigh the same but he is more on the skinny side and they are almost the same height. She grew 1 inch and with that inch she gained 1 1/2 pounds. So I would not catergorize her as unhealthy or overweight although I have noticed her fill out over the last year but we were happy to see that as she was always soooo skinny the doctors would tell us she needed to gain weight. We feel now she has a little back up for when she gets sick. Anyway, she eats very healthy. This urine test will be in addition to blood draws at this point in time. I have read they give a more accurate show of how the child is doing and wanted to try it. Sorry to ramble on. Julia