The aerobic activity is great for burning fat. Kudos to you for doing that. But a little weight lifting not only builds muscle, but it boosts your metabolism which in turn helps burn more fat, even when you're at rest. You might want to do some light strength training 2-3 times per week in addition to the aerobic activity you're already doing. I recommend a very easy watch-it-on-TV program from Prevention called "Fat to Firm in 20 minutes" to all my patients who are working on losing weight. I suggest they start out doing the workout twice weekly and keep up with thier walking (or whatever).