Why you lose muscle, not fat
The body prefers to hang on to fat and is more readily willing to burn muscle tissue for energy. Only as a last resort, the body will then decide to burn some fat to keep functioning.
The reason why our body burns muscle tissue before it gets to the fat is because muscle tissue uses up a lot of calories. In this way, if there is less muscle tissue, which burns a lot of calories, the body can survive for longer.
On top of it all, this will cause the body to deteriorate further and our figure will suffer. Having less muscle means that our bodies are made up of more fat than muscle. Now, the body’s new baseline for how much food we need has been lowered and if it ever goes above that, the body will produce more fat to compensate for the extra calories.
Why is under-eating bad in the long run?
In the long run, under-eating will only lead to gaining more weight and gaining more fat for the reasons explained above.
If you eat less, your body will begin to starve, which will cause the body to seek out nutrition from other sources, such as our muscle tissue. When we have less muscle, our bodies now have more fat.
Lastly, once we begin to eat more again, our bodies now determine that this is too much food and thus creates more fat to store the excess calories or fuel.