Research shows children usually start refusing new foods around 2 years old. From an evolutionary perspective, being unwilling to try new foods & only eating “safe” bland, beige foods is an adaptive strategy to avoid potential toxins.
As young infants, our children wholly rely on us for sustenance. By the time they’re toddlers & roaming freely, they’re able to start foraging for themselves. In modern times, this usually means raiding bottom shelves of the pantry for biscuits when we aren’t looking. In our history though, it meant they were at risk of incidentally eating leaves or berries from a poisonous bush. As a result, when they reach ~2 years they start to become very wary of new or different foods.
While we know that the foods we’re offering our children are safe (and good for them!), our children’s instincts to refuse them are the same instincts that would’ve protected them 1000s of years ago.
Another reason for why beige, yellow or white foods are so attractive is that they’re predictable. Crackers always taste the same, toddlers know what they’re getting when they take a bite. Blueberries? Depending on the season or how long they’ve been in the fridge they could be hard/squishy/sweet/tart/juicy.
Lastly, as parents we control almost everything in a child’s life. Things we can’t control: sleeping, eating, toileting. Common things parents struggle with: sleeping, eating, toileting. We often forget that when raising a child, we are raising a person. A person we want to grow into an independent individual, yet we can admonish our children when they demonstrate these traits.
It's important to give back control (or the illusion of it!) where we can. Maybe dinner becomes a picnic? Your child only eats sausages? Present a plate full of vegetable purees ‘sauces' to dip them in. It's important to get curious & find creative solutions to picky eating where we can. Whilst confusing & challenging for parents, these behaviours are very normal & usually temporary.
References: Rioux 2020; Helland et al 2017
(Second photo is a photo of my toddler's dinner last night!)