I pretty much knew that there had to be more to it than just "picky eating," and an eating disorder was mentioned in the video I posted. But, the video didn't say what the eating disorder was -- which made me wonder what it was. It was also clear that the parents had tried "everything" (that they knew of, at least), to get the boy to eat a broader diet, so it wan't over-indulgent parents.
The end result was nutritional, but the underlying cause was psychological. It was still an avoidable outcome, had the right kind of treatment been given at an early age.
Even in the 21st century, mental health treatment is still not what it it should be.