I have a bmi of 18.9, i exercise in the gym for about an hour 2 times a week (mainly weight training) and take regular walks (averaging 5000 steps) but i still have stomach rolls when i sit, is this normal or am i skinny fat?

There are many reasons why people have the amount of fat and muscle they have. Body type, the way they eat and exercise are important. A balanced healthy diet is best. Exercising in a way that burns fat and builds muscles is important. Start by seeing a dietitian to ensure you are eating right. Then have some sessions with a trainer to make sure your weight training is effective. Focus on health.

Your BMI is great as well as your exercise regimen. Small fat rolls will always appear, so do sit ups, or hire a PT at your gym for additional training. A healthy diet and drinking lots of water is important.