J.L.
Focusing on your son's eating pattern will drive you crazy. The little tiger doesn't have a death wish, he just isn't hungry. Don't make an issue out of it.
We are so often taught to follow the clock, instead our own natural body rhythms when it comes to eating. Allow your child to follow his own rhythm. If you are giving him artificial milk, you may want to check that the brand works for him. Breast feed babies are hungry more often, as breast milk is so easily digested. The formulas are more difficult and so babies need more time between feedings to digest them.
As he gets older, be sure to provide him with lots of healthy food - no junky premade baby foods with the salt and preservatives! Get one of those happy baby food grinders that you can use with whatever foods that you have on hand. Then he will learn to eat your food.
Trust that your baby is in tune with his body. He will not go hungry without making a fuss at this age. And as he gets older, if you push the feeding issue, he may use it as a form of attention getting. So give it up now.