If there was a definitive answer to this, one would be a billionaire!
It has to go in increments (this is my opinion). You have to establish where you are at THIS time in your life (and your ability) and if fat is what you want to eliminate, then your workouts should lean toward the calorie burn in the beginning. AWT workouts may be more helpful to you now (Aerobic Weight Training.) Circuit training is in the same genre depending on the weight used.
Heavy lifting is something to workup to, and if you haven't done this type of training, start with Intervals, Drills, AWT and full body workouts and go for the added burn.
Eventually switch up to heavier lifting techniques to build muscle to its peak. You'll create your own personal furnace. There's been a lot of debate about how much muscle really burns during the course of the day and I think all those calculations are estimates no one can prove anyway. All I know is in my world, heavy lifting equates to permanent fat loss, and I'm NO spring chic and have been doing this for years, so I have personal experience in what does work for me.
Some of my weight lifting friends contend that you should concentrate first on losing excess fat to see the muscle, but that's mainly from my guy friends. I contend a mix is more appropriate. Example, start with AWT and Intervals for a few weeks then gravitate towards heavier lifting (heavier weights, lower reps, split sessions). Keep a journal, eat clean, get lots of sleep and realize you have to get on the scale and don't freak out if the numbers go up a bit from time to time, its muscle swell (muscles repairing and holding on to water).
Its how you get to this point (safety wise) that's critical to success. Hence what I said in the beginning, your progress will go in increments and you will be *changing up* your workouts. You have to change up, and you have to advance on weights to get stronger. Its not going to happen over night, just don't give up.
Good luck !
