An international study of hundreds of thousands of children and teens found a strong correlation between consumption of fast food and synptoms of asthma, eczema, and rhinitis. Eating fast food meals at least three times weekly was associated with a 39% increased risk of severe asthma in teenagers.
What seems like an quick solution to hunger in a busy teen schedule seems to carry with a high risk of illness, serious illness. I would add the thought that any food that increases these illnesses would likely carry more serious risks over time, including obesity, diabetes and hypertension. But that study hasn't been done... yet.