By John McKiernan(NaturalNews) So many of us are concerned with staying trim and fit by eating right and doing cardiovascular workouts that we overlook the importance of building and maintaining muscle mass through diet and exercise. Having a lean and muscular physique provides many benefits. One of the most important is that muscle tissue burns through calories, even while at rest. This in turn increases the metabolism and boosts energy levels all day long, while keeping the body trim. Muscles also help burn the fat stores in the areas around them. This is why simple muscle building exercises like squats and pushups are just as important for fat loss as cardiovascular exercises.With that said, diet is of even greater importance when it comes to building and maintaining muscle mass. Most bodybuilders and fitness models will tell you that their training program, in terms of importance, comes down to about seventy percent diet and thirty percent exercise. These professionals know there are certain foods that are rich in protein and have high concentrations of essential amino acids, healthy fats, vitamins, minerals, phytochemicals, enzymes and other nutrients, all of which are crucial in supporting protein synthesis and and maintaining a muscular build. The foods listed below are known to be among the most essential for muscle development.