It certainly sounds like your waist is bigger than I would expect for someone of your weight. It would be unhealthy for you to aspire towards a
BMI of 17.6.
It may be worth speaking to your doctor about the bulge and seeing what they say.
I recently found that I had a bulge in my waistline and it transpired that my bowel had moved after a weakness had arisen in the abdominal wall (they did an ultrasound scan to investigate). I needed a hernia operation. Not every bulge in the waistline is due to
fat.