HOW DO I LOSE LOWER BELLY FAT (im VERRY SKINNY)?

Hello my name is james im 19 and weigh 143 lbs ive bin wondering why i cant seem to lose my lower belly fat i am already verry skinny but i cant seem to lose that fat from there. i run every other day and do crunches to try and get rid of it but it hasnt gone n doesnt seem to any time soon anybody know why this is? also i am the typ of person that love food with LOTS OF SALT so i dont know if that might b the reason but if you have any tips i will greatly apreciate it thank u sooo much