You should see that the body fat of abdominal muscles is at least below 18%, but obviously below 15%. Your height of 55kg is a little light. I think you should strengthen your muscles, because you are thin and your muscles are not obvious. You don't need to lose weight. What you need is to increase your muscles. Eat more high-protein foods such as beef and chicken breast during exercise, but try not to eat pork. Lean pork will also have 30% fat.