When I was a teenager, I tend to skip meals at school because I thought I am very fat, no I was not fat, I was just a little chubby. But since no one was able to notice what I was doing, I just pursue what I thought was the best for me to slim down. And the result was not good; I got sick and was almost admitted in the hospital. I got a severe stomach ache and my fever was so high. I was able to recover and was being healthy again. Now if your daughter is overly trying to slim down you might want to consult a doctor, she may undergo something that we don’t know. Also try to observe of any of this behavior:
Eats smaller portions or doesn’t want to eat.
Your teenager is most likely having the extreme of fear if being fat.
Deformed of body image.
Exercising for more than an hour or more.
Losing weight so sudden.
The period is irregular.
Always feeling cold
Has sleeping disorders.