I recently took my son for a check up. The doctor asked what he eats and I gave an honest answer. My son prefers cookies, cake, doughnuts, candy and juice to other foods. He isn't offered these too often, but tends to eat minimally when offered the healthier choices such as vegetables, fruit, whole grain bread, brown rice, salmon, hummus, refried beans, cheese, and tofu. Our family is vegetarian and I am bordering on vegan, so he isn't offered meats at home although he is never discouraged from eating them when offered at friends' of a restaurant. So far he has chosen not to eat them.
So, after hearing my list of foods recently eaten by my son, my doctor felt that he may be low in iron. She offered to check his iron, I said "sure". I felt my honor and career were on the line. After all, not only am I a Registered Dietitian with a master's degree in nutrition, I have raised my children and made a living believing that if children are offered a variety of foods, mostly healthy, they will get enough of the nutrients they need. So here was an objective test.
She used a finger poke and a hemoglobin test, done within seconds in her office. Normal for a child his age was a score of 11-16. My son came in at 11. I felt relieved and vindicated. Eleven seems like a good score for a child that eats no animal flesh, my scores have always been on the low side as well. I even asked my doctor if she felt I should supplement his diet. She said no, just give him high iron foods. I smiled and said "I will offer him high iron foods, I can't make him eat them."