I too have had a lot of difficulty finding reliable information on early proteins. It is hard to find much academic research on the topic, and what I do dig up is quite old and difficult to access. For example, I found several references from the early 1980's, mostly from anthropology journals and nursing manuals, but actually finding copies of the texts has proven extraordinarily difficult. I have access to several academic libraries, and one of these days I will go in person to dig up the dusty, yellowing volumes. I have become spoiled by online access to most research references -- spending actual time in the stacks seems so antiquated!
What I could uncover in the published literature aligns with your findings that babies are usually given small, well-cooked amounts of whatever adults eat. There are also several references from the late 1970's written by folks reporting on "developing" and "third-world" countries (it all smacks of the early Peace Corps and Margaret Mead "living amongst the natives"). The authors discuss the primacy of breastfeeding and report that the "tradition" is to wean babies on to porridge. Several authors discuss a paucity of meat in infant diets or document "taboos" against protein-rich foods for kids. What goes unexamined, however, is whether these choices are purely "cultural" or if they are in fact a reflection of general food scarcity due to geopolitical forces. One also wonders if a "taboo" against feeding kids high-density foods like fat and protein actually represents a community allocation of nutrition resources to adults struggling to keep their families alive with manual labor.
There was an interesting article on the La Leche League website , about cultural differences in baby feeding practices. She, too, seems to have honed in on the political issues behind "cultural" feeding choices:
The staple food in Niger is a grain called millet. It is frequently the only food available and is not a complete protein. Even if there is meat available, women and children may be the last ones served.
It does seem that the author made an attempt to cite actual references rather than repeat the general stereotypes you so rightly pointed out in your last post. On further examination, however, these references are, with one exception, non-primary sources - mostly breastfeeding manuals. The author reports the early feeding of fish in Oceana and Japan, as well as the possibility of insects and grubs as a protein source. Despite the usual reports of no grease and animal fat for babies, she also cites how Inuit people feed their babies seal blubber. All of this deserves further examination, especially given the citations, but I appreciated the general tone of acceptance in the article. I also must commend her lack of disclaimers about "talking to your pediatrician before starting any solid food before the age of three", or other such nonsense.
On a more personal front, many mothers I know of Mexican and Salvadoran origins tell me that their infants' first exposure to proteins is traditionally meat broths, although lentils are also a common infant staple. Meat broths are considered nutritious, easy to digest, and have "baby-friendly" flavor. With my own child, his earliest proteins were mashed egg yolks, black beans and salmon. After 9 months or so, we would give him a chicken bone to gnaw on with some meat attached. In general, though, most of his proteins were milk based, both human and cow. He ate a lot of yogurt, cottage cheese and ricotta. I tried the meat broths but quickly tired of having to gently spoon everything into his mouth while avoiding his impatient little fists-- so little of the soup ended up in his tummy, and so much ended up on his shirt! I liked feeding him thicker things that he could try to eat himself, or at least had less propensity to dribble off the spoon prior to touching his lips.
The one thing that continues to bother me about fish is the issue of pollution, mercury and other contaminants in fish. I wanted to share an article that I found helpful in the New York Times that listed the fish and seafood that are safe for young children and pregnant women to eat on a weekly basis. Helpfully, the list also excludes fish that, though potentially safe, are poor choices from an ecological perspective due to overfishing, bad farming practices and the like.
Finally, both of us have chosen to eat meat and are also raising our kids omnivorously, but while investigating the subject of proteins for babies, I have also become interested in some of the debates about raising babies on vegetarian, vegan and even raw diets. I imagine that you know some moms who are doing this -- I know many vegetarian moms, some due to lifestyle choice, many for religious reasons. Have you found any information on this topic?
Be well, Abbie