One person's opinion... I used to run a lot, marathons etc.. I was pretty fit, low 3hrs for 42km. I never really noticed a dramatic change in body composition from all the cardio I did. A couple of years ago, I started lifting weights 3 times a week, got my 10k steps in most days, maintained a calorie deficit most of the time, ate 50% of foods from protein sources and boom, dramatic results. Just my 2 cents. Best of luck on your journey.