The way we feed our children has a little to do with science, and a whole lot to do with culture.
In the U.S. we typically recommend starting your infant on solid foods by about 6 months of age. Data from the World Health Organization suggests that introducing solids much earlier may interfere with optimal breastfeeding and lead to increased risk for infections and nutritional deficiencies, and waiting much later can also lead to some important nutritional deficiencies.
These recommendations have changed through the years. Around the turn of the century in the U.S., children weren’t given solids until around 7 months. After World War II that age dropped to about 6 weeks (coinciding with the availability of commercially prepared baby foods and some very heavy marketing), and has gradually crept back up to the current recommendation of 6 months.
In many parts of Europe, the average age that babies are introduced to solids is closer to 4-5 months. In Ireland, about 25% of babies have their first solids by 12 weeks. In Japan there is a common ceremony giving infants their first exposure to solid food that takes place at 100 days. In Zimbabwe, the average age is 3 months, in Brazil 4 months, and in Nigeria 6 months.
So if you are trying to find your way through a maze of advice and recommendations, remember that there is a lot of variety in how we feed our children. Right now, our best evidence says that 6 months is a safe time for most children to start exploring solid food – but the difference of a few weeks either way is probably not a big deal.