When the moment comes (usually after 3 years) that the child consciously asks you for sweets or candy, give it to him, while repeating every time why it is harmful (teeth fall out, stomach hurts). Show a photo of black children's teeth, it usually shocks them.
Sweets are different and some of them, for example, marshmallows or nougat, are often not to their liking. Give children exactly those sweets that they like less than others.to evoke unpleasant associations in them.
Give the right signals! Crunch and smile when you eat vegetables and fruits! Make sounds of pleasure. When chewing junk food, make a sour face, showing that you are not tasty and that your tummy hurts. Children love emotions) they are guided by them and the first years of life.
Cook your vegetables deliciously! Children do not like the soft texture, they need crunches. Bake or lightly fry the vegetables. Make colorful meals that are fun to eat.
Do not eat nasty things yourself! Do not keep it at home, supposedly for guests. Children see and remember everything. When setting the table for guests, there is no point in forbidding the child. But always explain to him what the dishes are made of and why eating them every day is harmful. And often leave the choice to the child himself, prompting with your eyes that this is useful.
We, the parents, personally form the child's healthy or unhealthy eating behavior. All in your hands! Which tricks are you already using?