A popular misconception in fitness and nutrition circles is that it is impossible to build muscle and lose weight -- via a caloric deficit -- simultaneously. While this is not impossible to do, it can be quite difficult and requires several specific circumstances to be in place. First, you must be significantly overweight with a high body fat percentage. Second, you must consume a diet conducive to muscular hypertrophy. Third, you must engage in a consistent program of weight training.
Body Composition Requirements
Because the human body is designed to sacrifice muscle when losing weight as a survival mechanism, only a certain body type will permit the simultaneous growth of muscle and loss of overall mass. If you're significantly overweight, your body may be able to support increased muscle mass even on a caloric deficit, provided it has less fat to maintain. If you're relatively lean and/or muscular, however, it is much more difficult for your body to increase muscle mass while experiencing a caloric deficit.
While a caloric deficit implies that you're eating less food overall, it is possible to increase your protein intake during a caloric deficit by adjusting your diet to include more protein-rich foods. To succeed in building muscle and losing weight simultaneously, consume 1.6 g of protein per kilogram of bodyweight daily. To meet this goal, you'll likely have to rely heavily on protein sources, such as meat, fish, beans, eggs and tofu. You may also consider a powdered protein supplement.
To build muscle while losing weight, you'll have to train with a high degree of intensity. Since the body's natural inclination is to sacrifice muscle when losing weight, training is the only way to provide a stimulus that lets your body know that muscle is needed. To maximize this stimulus, focus of heavy, compound exercises, such as the bench press, shoulder press, bent-over row, squat and deadlift. For each exercise, perform three to four sets of eight to 12 repetitions for maximum muscular hypertrophy potential.
Other Lifestyle Requirements
When experiencing a caloric deficit, your body is under stress. This can inhibit muscular synthesis alone, but it becomes particularly significant when combined with other stresses, such as those deriving from the use of alcohol and drugs. These substances can have a negative impact on the production of important muscle-building hormones, such as testosterone. You should avoid them as much as possible.