Physicians found he lacked vitamin B12 and vitamin D - which are found in offal, milk, fish and eggs - as well as a reduced bone mineral density and low levels of copper and selenium.
The unnamed boy from Bristol went to his doctor when he was 14-years-old after complaining of extreme tiredness and loss of hearing.
The teen was diagnosed with vitamin B12 deficiency and given supplements, but he did not continue to take them.
He is taking vitamin supplements and his colour vision has improved slightly.
ARFID, which was previously referred to as "Selective Eating Disorder, is similar to anorexia in that both disorders involve limitations in the amount and/or types of food consumed, but unlike anorexia, ARFID does not involve any distress about body shape or size, or fears of fatness".
The case report published today [2 Sep 2019] in Annals of Internal Medicine. He's now unable to drive or properly recognise people's faces. But if left untreated, it leads to permanent blindness.
By the time his condition was diagnosed his vision was permanently impaired.
The problem with nerve cells in the optic nerve is that they can't fix or regenerate, she said, so any nerve loss is permanent.
Dr. Denize Atan, the study's lead author and Consultant Senior Lecturer in Ophthalmology at Bristol Medical School and Clinical Lead for Neuro-ophthalmology at Bristol Eye Hospital, said: "Our vision has such an impact on the quality of life, education, employment, social interactions, and mental health".
"Unlike anorexia nervosa, it is not driven by weight or shape concerns".
Doctors said that he had developed an avoidant restrictive food intake disorder, which stopped him from eating certain nutritious foods. This was treated with vitamin injections and he was warned to get his act together on the dietary front, only to lapse back into the processed pale factory foods again. Blood tests confirmed he was deficient in iron and vitamin B12.
"Technically, someone who only eats chips and crisps is vegan - so, too, would be someone who eats only rice and pasta and so on, but these are not examples of healthy diets".