Starting solids sensibly: A guide to starting baby on solids | Baby basics aren't always so basic, just when you think you've mastered milk feeds, there's a new bump in the road - introduction to solids. Around 6 months, breastmilk or formula alone no longer meets the nutritional requirements of your baby. At this stage milk remains the primary food source, however the addition of solids is necessary in order to fill the gaps of specific nutrients that are now needed in greater quantities.