Weight loss is commonly determined by watching the number on the scale go down. However, your weight may decrease due to the reduction of anything within your body, whether it is muscle, fat, or water. It is important to note that most people actually mean "fat loss" when they set their goals; thus the term "weight loss" used from here on will refer to this definition of the word.
To achieve weight loss, you must create an overall calorie deficit by reducing the calories you eat or by increasing the calories you burn through exercise, or through a combination of both. A total deficit of 3,500 calories will result in the loss of 1 lb. of body fat.
Muscle mass is particularly important in weight loss regimen for the sheer fact that lean muscle requires the body to burn more daily calories just for maintenance. According to Weight Loss Resources Ltd., every pound of muscle burns up to 50 calories more each day than other types of body tissue, which adds up to pounds of additional fat loss over time. A person with just five extra pounds of muscle can lose a pound of body fat in two weeks just by maintaining their daily calorie levels without exercise. Of course, combining a strict diet and exercise into this equation will ensure and speed up the weight loss process.