Baby-led weaning (BLW) originated in 1926 as baby feeding study by Clara Davis, carried out at the Mt. Sinai Hospital in Cleveland. In this study, Davis fed a group of orphans by putting a variety of foods in front of them every day.
The first thing to notice is the choice of foods that Davis considered important for babies. These included “sweet milk”—in 1926, that would be whole raw milk—as well as sour milk. In addition to fruits, vegetables and grains, the babies got to choose from beef, lamb, chicken, bone marrow, bone jelly, sweetbreads, brains, liver, kidneys, fish and eggs. Notice all the organ meats and the lamb jelly! To top it off, babies got to dip their fingers in a bowl of sea salt! Most importantly, Davis did not give the infants any foods containing sugar and white flour.
The babies studied by Davis developed definite tastes. For example, one baby ate two pounds of oranges in one day. I’m not sure I would call that a “balanced diet.”
But the key point is this: In the Davis study, the foods were mashed, ground up or finely minced—not raw and in big chunks. Moreover, when the babies indicated what they wanted, the nurses fed them with a spoon. Babies also ate with their fingers. The baby-led weaning folks have definitely twisted the Davis study to justify giving babies raw broccoli or raw carrots as their first foods!
This is a long way from what I hear as part of conversations around BLW with some parents relaying to me that it is really just about giving their baby options. Often many of the foods that are part of the original study are not offered at all.
Longer lasting effects that happen is that the exposure to different tastes (sour, bitter, salt, astringent, pungent, sweet, unami) in the early days means that children are much more likely to try different foods as they grow up. Yes kids will still go through phases of not eating certain foods (this is part of growing up!) but you will be able to incorporate a much more diverse diet if a wider range of flavours are introduced in the first 12 months.
I tend to lean towards parent led feeding as this allows for the parent to be in control of the 'what' food is there with a much higher degree of confidence.