My boy was born at 8lbs 5ozs and is only a tiny 13lbs 7ozs now at 17 weeks. We have been advised to start solids to help him gain weight. Not sure what I'm going to do. My 1st baby was weaned from 17 weeks (that was the recommended age when he was born) due to reflux but he gained weight very quickly despite the reflux. He's 2 yrs 9 months and is 98th centile. It seems they just say it for the sake of it.