you make it sound like its hard to maintain. Not to belittle a 30lb loss in 9mos, but after 9mos of my lifestyle change (including a shift to paleo nutrition) I had lost ALL of my excess body fat. That turned out to be about 100lb from my heaviest. But, had I been heavier, I have no doubt I still would have shed every bit of excess weight, whatever that number has been. I often encourage people to take up the paleo diet because its fairly simple to maintain (avoid grains, starchy foods, legumes, and the oils derived from them for the most part) and, due to the nature of protein having a high satiation effect, effectively also reduces your consumption of food in general. If someone wants to burn fat they first have to train their body to actually USE fat. That's never going to happen if you continue to eat a lot of carbs. Carbs are the low hanging fruit of fuel for your body. As long as there is plenty of that sort of fuel laying around your body is going to use it and never use fat. In an absence of glycogen, your body will begin converting a 9cal fat gram into a 7cal ketone; which, once converted, cannot be re-absorbed as fat. You either use it or piss it away. So before you've made any other lifestyle change, you're already getting a 25% bonus to your BMR out of basic inefficiencies.
Compound this by training your muscles to burn more fat for fuel instead of carbs and you accelerate the weight loss significantly. White, fast-twitch, muscle fibers burn glucose and cannot oxidize during use, resulting in tired sore muscles after a short stent of activity. Whereas red muscle fibers of both fast and slow twitch burn fat directly and can self-oxidize during use. The calves of an Olympic sprinter are majority white muscle fibers, whereas a Olympic marathon runner re quite the opposite where 80% of the muscles in their calves are red fibers. This can be achieved by structuring your workouts to focus more on endurance and increasing workout times than trying to first increase resistance. Enough resistance to keep your HR within the cardio/peak ranges, but once there, focus on endurance building.