They both could die! No formula is not the end of the world. My DIL breastfed grandson for 18 months! He had absolutely ZERO but HER. No one could give him juice, water, cereal, zip, zero, nada! She LOVED the absolute control. My son was only allowed to feed him 1 bottle, 4 ozs. Pumped breast milk a day. And never without her there! He is now 9, won’t eat ANYTHING, absolutely nothing but Chicken Nuggets from Mickey D, Kraft Mac n cheese, Flamin’ hot Doritos, Vanilla ice cream and Nutella sandwich with NO CRUST and occasionally pancakes or cereal. No milk, butter, syrup, or any juice. Water or chocolate milk. His sister eats ANYTHING(5)! His Dr has never once mentioned that he should have a more “inclusive” diet. He is below avg height , weight, and has worn the same size shoes and clothes for close to 3 years. I wouldn’t take a child to a Health Professional unless he had something I could not fix myself. His parents are crazy but think us grandparents are nuts because we say he should be eating more. They think it’s great cause less work for them. 4 nuggets, 1/3 cup Mac n cheese, water for dinner. EVERYDAY! Also, he now will not eat anything new without gagging! Don’t think he’ll be going on many dates!