Good for you as well... the Apple Watch won't make you lose weight unless you want the motivation but the rings can get into your head to complete them and it helps. Even 500 calories a day equals 1 pound over 7 days and if you eat the same, you will lose weight.
170 may or may not be fat depending on your height, body frame and muscle mass. The BMI calculator says my BMI is 25 and that I am obese, but I am 6'4 and I know my actual body fat count is way lower than that... It doesn't know what to do with muscle mass. Your testosterone can go up at your age with simple weight lifting exercises and your cutting won't even matter as muscle mass takes up less space than fat and weighs more.
Good job though!