A recent question on an online parents' discussion board was about which brand of rice cereal to introduce to a 5 month old son exclusively on breast milk. I answered with the following response:
Contrary to current practices and ideas in the U.S., rice cereal is generally not a good first food for babies as they cannot digest it properly. For starters, it causes a spike in blood sugar that is very unhealthy for babies (even the brown rice varieties). But even more problematic is the fact that little ones don't produce salivary amylase for digesting starches until their 18-month molars come in -- and sometimes teething is delayed, so it is actually best to wait until 2 years to introduce starchy foods and complex sugars. It may seem like poor digestion of starches is not a huge deal, but it is because improperly digested starches and sugars will hang around in the baby's gut, providing excellent food for pathogenic microorganisms. This can greatly upset the delicate balance of digestive microflora in the baby's system, which can cause many problems either immediately or down the road. The proper balance of digestive microflora is crucial for 1) good digestion, 2) proper absorption (and synthesis) of nutrients, 3) healthy immune function (including combating pathogens that come into the body via the mouth), and 4) elimination of toxins. Starting babies on rice cereal is a good way of getting them on a pattern of expecting blood-sugar spikes, and will often lead to cravings for refined carbohydrate-heavy foods (pasta, bagels, cereal, bread, crackers, etc.).
If baby is satisfied and growing well on breastmilk there is no need to introduce any other food until about 6 months, when it's a very good idea to add some iron-rich easily-digested foods to baby's diet (breastmilk is low in iron and baby might need some more around 6 months -- however, some babies' iron stores will be fine until 9 months or even longer on a diet of nourishing breastmilk from a healthy mother). An excellent example, which traditional cultures from around the world have taught us, is a small amount of pastured/organic liver from chicken or beef. This can be simmered gently in broth and mashed with a little unrefined sea salt (high-quality unrefined sea salt aids the formation of glial cells in the baby's brain! look for Eden, Remond, Celtic, and Himalayan brands at the health food store or co-op). Liver is a traditional food eaten by cultures around the world for a very long time indeed, and has the benefit of being easily-digested by little ones since they are equipped to handle nutrients that more or less mimic the nutrient profile of breastmilk: animal-based fats, cholesterol, protein, and the milk sugar galactose (found in breastmilk and in properly-cultured yogurt). It is richer than any other commonly-consumed food in many nutrients important for baby's growth and development (vitamin A, vitamin C, easily-assimilated iron, all of the B vitamins including folic acid, CoQ10, trace minerals, etc.). It is important to get high-quality liver; the co-op carries pastured chicken liver, and Whole Foods has organic. Let me know if you need more help sourcing. I should also mention that it worked well for us to introduce small bites of pre-chewed food at around 9 months (which is when our son was finally interested), which has the benefit of already being slightly digested. Many animals/birds, etc. (and of course humans from other cultures) use this method and it works quite well -- easy, quick, much less work, and better for the baby. Again, you would simply focus on foods that are highly digestible for the child: animal protein, well-cooked non-starchy non-fibrous veggies (such as winter squash, zucchini w/no seeds or skin, etc.), bone broths, etc.
Another highly nourishing first food is gently-cooked egg yolk (soft, but not runny) from a pastured/organically-raised chicken, also seasoned with a small amount of unrefined sea salt. The special long-chain fatty acids in the yolk will be highly nourishing for babies and aid in brain and neurological development. The whites should not be introduced until after the age of 1. As with all new foods, go very slow and introduce only a taste at first, then a little more each day. Many babies need time to adjust.
There are other excellent first foods I could recommend, but will leave it at this for now. Good luck with your feeding adventure!
Oliver is enjoying some mashed d'Anjou pears with raw milk yogurt this morning. He seems to forget he likes them at first, then gradually becomes accustomed. At this point he can eat about 1/8th of a pear -- an incredibly tiny amount! I core and peel the sliver of pear of course, then mash it in a little bowl with a baby spoonful of yogurt. The rest of the pear waits in the fridge for following days.