I'm going to guess you were a chunky baby girl. You see Baby Fat Cells develop when we are babies. Oh yes, mothers love to show off their babies especially when they appear well fed nice and rolly. When we become 18 and want a slender body .... NOT! Baby fat cells never go away. They just empty for a while and are quick to fill up again. That's why doctors are making millions! Thanks to mothers who loved to have rolly polly babies. Now they pay bundles of money getting lipo suction which brings on other medical problems. I want to thank the Depression and the poverty in my family for my body. We only had enough to eat once a day which kept us lean (skinny). I hoover at 172 pounds at 5 feet 10 inches because I do not have too many baby fat cells. Also recently there was a study being done which was to prove that we all have a gene that determines our body structure. See your doctor and have him determine what should be your ideal body structure. As for being on the beach and looking a bit "over fed". Just remember, there is someone in the world that would love to look the way you do. They are getting by on roots and scraps and you could count all of their bones. So be thankful. Stop complaining.
Um 52 kilos (about 114 lbs) that sounds about right for some one your age. None of the things you are doing right now are converting that fat to muscle. Along with running (cardio) you need to do some weight training to lose the fat and build muscle tissue. Also, cut down on the pasta, it's packed full of calories. If your not doing any cardio it will turn to fat.