Adding muscle is 1) extremely difficult (no, you cannot add 30 lbs of muscle in 30 days unlike the ads would make you believe) and 2) the effects are largely exaggerated.
Quoting Lyle McDonald, a noted leader in fitness science and nutrition :
"Some of this also comes from the still gross misconception that ‘muscle burns a ton of calories’ (a myth I took apart in Dissecting the Energy Needs of the Body – Research Review). That is, they hope to jack up metabolic rate by increasing muscle mass. Which is a futile activity because the effect is minimal (on top of the fact that the obese are already carrying extra muscle mass). A pound of muscle burns about 6 calories at rest, you have to add a ton to impact on metabolic rate (see also the next issue I discuss, low metabolic rate isn’t a problem). And that takes a lot of time, time better spent focusing on active fat loss."
Quoting Lyle McDonald, a noted leader in fitness science and nutrition :
"Some of this also comes from the still gross misconception that ‘muscle burns a ton of calories’ (a myth I took apart in Dissecting the Energy Needs of the Body – Research Review). That is, they hope to jack up metabolic rate by increasing muscle mass. Which is a futile activity because the effect is minimal (on top of the fact that the obese are already carrying extra muscle mass). A pound of muscle burns about 6 calories at rest, you have to add a ton to impact on metabolic rate (see also the next issue I discuss, low metabolic rate isn’t a problem). And that takes a lot of time, time better spent focusing on active fat loss."