The flavors of food a woman eats while pregnant are present in amniotic fluid and swallowed by the fetus. Later, if she breastfeeds, her baby will taste the foods she prefers via her milk. This may be how cultural food norms are passed along well before a child ever eats solid food.
This was demonstrated in research published in Pediatrics over a decade ago. Filmmakers working on the documentary Carb-Loaded ask, what about today’s diets? Are babies learning to prefer soda, fries, and burgers?