Is this normal baby feeding?

I had a friend over here with a baby boy who is the same age as my daughter-- 7 months. He is very chubby, and my daughter is very skinny (no baby fat) but she is longer than him. His dad said that he eats every 6 hours 5 oz and only sometimes he feeds him "food in a jar". He said that the doctor told him to feed the baby this way. I am wondering if he is starving the baby by feeding him every 6 hours?! I myself am starving by every 3 1/2 hours as an adult. My daughter drinks every 3 hours-5oz. And she is eating solids between her feedings. Is he starving his baby boy? Is this healthy?