There are two types of eating disorders among teenagers
nowadays.
One is anorexia nervosa, the other one is bulimia. They want to
eat less and keep thin even though they are already very thin. But
they are under nourished, so there will be a noticeable change in
them. They will become skeletally thin, drift apart from friends, a
change in their behaviour and much more... The person will change
so much that even your best friend seems to be a stranger
anymore...
Bulimia is also as harmful as anorexia nervosa. The teenagers
eat and eat and eat, until they are about to explode. Then they eat
laxatives and vomit everything out. This will have a harmful effect
on their bodies. Cos I learnt in Biology lesson that when a person
keep forcing themselves to vomit, their vomitting reflex will stop
working and they can't vomit anymore. So, they may eat until they
are bloated... then mati...