I am 43, a twin and both of us have pectus excavatum. One of his three kids, a son, and one of my daughters also have P.E. So this is hereditary and no it is not from malnutrition. My brother and I never were set back by P.E. Our favorite sport was and still is water skiing.
I think the new procedure with putting a bar in the chest sounds like a good procedure. I am going to see if this might be an option for my daughter.