You can't take this test as completely correct (in fact it is very incorrect in most cases) as you are answering just a certain set of questions. If there is one or a few things that you are finding very hard to cope with then see somebody, but if not then don't listen to the test. Most 13 year olds have low self esteem and issues with eating etc. Being a teen is hard and often people get depressed (mostly middle-class people). If you feel down it is likely that it is just what all other teens feel, but if it becomes a serious worry, stop taking tests and see your doctor.
My sister had anorexia for four years and I have seen the horrors of it. So, if you have worries about it, i advise you to see someone, but keep in mind that most people are odd about eating. For example, even though I have seen first-hand how stupid anorexia is, I sometimes go on starvation week. I quickly realise it is stupid and stop, it is just called being young.
I hope you are okay xxx