I used MyFitness Pal for my lifestyle change. Your body uses a certain number of calories for energy per day and if you stay under that you will lose weight no questions. The app makes it simple but you have to get into the habit of tracking every meal or snack. Once you do it long enough you can get pretty good at estimating your calories. It just makes you calorie aware. I still indulge occasionally or have cheat days where I eat whatever, but I now like eating a proper number of calories per day. I just feel better, and lost 25 lbs of fat. Running 2 miles a few times a week is something that will take only 30 minutes or less each time and it will boost your metabolism and give you some good cardio. It was pathetic how out of shape I was when I started, I could only run maybe a quarter mile then I would be winded and wanting to walk. Now I can easily do 2 miles at a decent pace without issue, I still kinda hate running but I hate it less, and it is quick to get it done. I like the gym but it takes more time.