I don't know if I'm over-reacting, worrying too much or if I should be more concerned.
DD is 15, 16 in January, generally happy and healthy. However, her eating habits are worrying me. She knows all about 'healthy eating' yet she will buy and gorge on sweets and cakes at any opportunity. She also buys Red Bull although I've asked her not to and told her it's bad for you and can affect sleep,, etc. I make a good, healthy dinner for her (she is also vegetarian) and she often leaves most of it and then tries to grab chocolate biscuits ten minutes later (I suspect because she's not properly hungry for dinner as she's snacked so much).
Also, she never eats breakfast and her lunch is a mishmash as the school food is not great (she won't take a lunchbox although I keep offering).
I've spoken to her (at length, I'm afraid) about being healthy etc but I've just found an empty can of Monster, Red Bull and an empty pack of cakes on her shelf 
What can I do? She buys stuff after school and I can't monitor that - I've already massively cut down on what junk food we have in the house and there are always healthy options here such as fruit.
Any advice or empathy welcome!!!