Here is the stone-cold fact: One pound of muscle increases your metabolic rate by only 6 calories per day! Now the real kicker is that realistically, per month you can only expect to gain as much as 1 to 2 pounds of muscle if you're male; females can add up to half a pound of muscle per month. That's assuming you're training consistently and eating adequate amounts of protein. This just lets you know that gaining muscle takes just as long as weight loss, and doesn't boost metabolism much at all, so it's not the quick answer to losing more weight!
Does this mean you should give up weight training all together and not worry about muscle mass at all when losing weight? Absolutely not! I recommend doing cardio at least five times a week and resistance training two to three times per week for the most success when actively trying to lose weight. When you lose weight and create a caloric deficit, your body does not discriminate between fat (your fat stores) and muscle (your lean body mass), so it just takes where it can.
Resistance training helps to preserve your lean body mass when you create a caloric deficit, leaving you strong and not emaciated. Do you have your weight training schedule ready for your weight loss program? Talk to a personal trainer or take a circuit training class at your local gym. This will ultimately help you stay lean and lose weight at the same time.