But playdough when they chose not to eat did you let them go hungry?
You don't have to let them go hungry. You can allow them to have some fruit but only the amount you would like them to eat.
The best principle is to provide what you would provide if they were not too fussy. You put a meal on the table that you know is reasonably palatable to them, you eat and allow them to choose whether to join in and then you clear away. You then provide dessert/fruit as you would have done if they had eaten so perhaps one piece of fruit.
You don't allow them to take extra to fill themselves up but you could make sure they have milk before bed to help them to sleep.
You don't change the balance of what you offer depending on what they have eaten. You just plan meals, provide them and clear away without taking any notice whatsoever of what they eat.
That removes pressure to eat (which can suppress their appetite very effectively) and any opportunities for negative attention and power games.
Don't fight, cajole, reward, bribe, punish or praise any eating ever. Don't discuss the food at all. Talk about everything but food so that mealtimes can be pleasant experiences.
Just present the food, eat yours and clear away every meal time without comment.