Have you ever experienced this kind of situation whereby, you have been working out for three or more hours per day, but you do not seem to be losing any weight whatsoever, nor do you seem to be gaining any muscles, even though you do not eat much? Why is it that your friend can eat all that he or she wants, no work out much, have less fat mass and more of lean muscle mass, while you must do all the hard work and exercise in the world, not eat anything, and yet stay fat?  Whether you are gaining fats or you are gaining lean muscle mass, the increase or decrease, is always in response to an energy imbalance.
Although it is not such a simple pursuit to be able to maintain patience, persist, stay disciplined, and dedicated, achieve substantial weight loss, and then even maintain the new healthy weight, yet the underlying principle of weight gain remains the same.
The no.
of calories of whatever you ate minus the number of calories of whatever energy you used up during your periods of activity, defines the amount of fat mass or lean muscle mass gained by your body.
If somehow, some people seem to be gaining more weight than others, while making sure that both of them were taking the same quantity of food, then probably the difference lies in the fact that one may have expended more energy than the other.
However, recent studies have also proved in animals as well as rodents that those individuals with greater levels of growth hormones in their body, seem to lose weight even if they eat more.
One thing about the growth hormone is that the levels of growth hormones in the body rise and fall a couple of times, during the duration of an entire day.
It has been noticed that those who seem to lose weight in spite of eating more, not only have higher levels of growth hormones, they also mark higher spikes during the rise and fall of their growth hormones during the day, than those who tend to gain weight while eating more.
If infusing growth hormone in a human body implies greater possibility of losing weight, for that particular human being, then infusing growth hormone, may be the key to helping those people who suffer from overweight, obesity or morbid obesity problems.
  The problem with the natural rate of production or release of the growth hormone is that as you age advances more and more, the lesser the amount of growth hormones released in the body.
Again, as you gain more and more body weight the production or release of growth hormones reduces in the body.
However, there is some good news.
You can reverse the low release of growth hormones, as your age progresses by simply doing more exercise, body building, muscle toning work outs or increasing your level of physical activity, thereby increasing natural growth hormone production of your body, and in turn promoting increase in lean muscle mass and decrease in the body's total fat mass.
Thus exercising helps with the dual benefits of not only burning up the excess calories that you have consumed during the course of the day, but it also helps with promoting the natural production of growth hormones, which are mainly responsible for weight loss in mammals.
Thus you can use your body building exercise regimen to create a two-pronged attack, against the problem of fat accumulation, and replace it with lean muscle mass accumulation.