Leg workouts definitely help burn fat more than say chest/shoulder workouts. Do squats, lunges, raises, etc. You'll feel like shit if you have to walk up/down stairs for the next three days, maybe more, but it's worth it.

I think you should do more cardio and watch what you eat.

from the body's biochemical point of view, try to lift heavy weights first to use up your sugar and glycogen sources first, then lead into cardio to burn fat cells, instead of the other way around.

for example set up routines for each day followed by 30~45 mins of cardio.. balancing your workouts around every major muscle group on alternating days is one way to do it, also add leg workouts, be it squats, box jumps, deadlifts every day as well.

you have alot of glycogen storage in your lower limbs, and you want to get rid of that source of energy before you get into cardio so you can really start digging into your fat cells...

if you've got a good routine, you should really be gaining weight while looking slimmer/better on certain parts of your body for an overall healthier look!