The best eating advice I’ve ever received was the division of responsibility.
It’s your responsibility to offer food. You choose which food, and when. It’s your child’s responsibility to eat it. They choose how much they eat, and if they eat at all.
Always offer food they will eat alongside a new food so you’re not getting them something else if they refuse the food you’ve given them.
And pray to God they actually eat it.
Godspeed.

The best eating advice I’ve ever received was the division of responsibility.
It’s your responsibility to offer food. You choose which food, and when. It’s your child’s responsibility to eat it. They choose how much they eat, and if they eat at all.
Always offer food they will eat alongside a new food so you’re not getting them something else if they refuse the food you’ve given them.
And pray to God they actually eat it.
Godspeed.

Also when it really becomes an concern (when it becomes a health, well being or safety concern, I would most certainly visit the GP, who could possibly refer you to a health nurse, a dietician or in some cases, an Occapational therapist.
In the meantime it is important to keep meal times low stress, no pressure, offering familiar foods alongside a small portion of a new one. And share mealtime with the family.

So good that your teenager became less fussy and started to eat more variety once he grew !
What are the things your four year old is currently willing to eat and would you be able to make some little adjustments and variations to that ? For example, when it is pasta, you can add a lot of fresh veggies and lentils to the sauce, or when your four-year-old eats cupcakes, you could add a hidden veggie.

I agree with the first comment, encouraging them to try has been very useful. Even if I manage to get my toddler just to lick it I’m happy hahah. Then my alternatives aren’t exciting. It’s a banana, buttered toast, or a piece of cheese. But I’m lucky that he will always eat his veggies and fruit. I imagine it would get tricker as they get older and want to push back. I’m about to have my second and have no shame in saying I have a lot of home made Bolognese sauce portioned and frozen to give the toddler. At least he’ll be having something he likes and its full of protein and lentils

You are so right! It’s definitely something they usually grow out of but for me I found making a big deal out of even just a tiny try of something new helped. It didn’t matter if it was just one tiny mouthful I would always high five and say awesome job at trying something new. They relaxed because they knew I wasn’t going to force them to eat the whole plate, all I asked was a little try. In time I found my children wanted to try more and eat more. Hope it works for you