Generally speaking, weight loss (fat or muscle) is a function of eating less than you burn in calories.

But then again, its not that simple. How food, sleep, sun, stress and other factors elicit hormone responses is key and those hormone responses will determine what energy sources the body will use and where it comes from - which may not be from where you want it to come from - like body fat.

If one wants to achieve a healthy body composition, they have to be concerned for the condition their health as it affects normal cell and hormonal functioning. So not only should we be concerned with "calories in - calories out", but also those factors that are disrupting our health.

If you have struggled with a healthy body composition and/or tried numerous weight loss approaches, you can appreciate this.