Most people don't understand that a "diet" IS WHATEVER YOU ARE EATING ON A REGULAR BASIS.
Weightlifters are on diets, as are athletes of the more mobile sort (often being 10,000+ calories a day).
Anorexics (active or rec from) are on diets.
People trying to lose weight, gain weight, get healthier, combat certain physical issues (diabetes, vitamin A intollerance), vegetarians, pescatarians, vegans, kosher, halal, or who are just eating without thought are ALL on a diet. (as are everyone)
You're on a 'special diet' of what sounds like 'balanced moderation'.
The splitting hairs REASON?
Because that's your answer. We're all on "a diet". Your diet just so happens to include certain things and exclude others, increase certain things from your normal diet and decrease certain things from your normal diet. As do all of ours.