There are 3500 calories in 1lb. If you take in 4,000 calories one day and only burn 3,000 calories you have a balance of 1,000 calories. If you continue this cycle in less than 4 days you would increase your weight by 1 pound. The average American eats more than they need to consume. To compensate they try to starve themselves for a day or two to get rid of the unwanted weight.
When you starve yourself you are doing more damage than good. I know most think, “I’m not taking in calories so I am losing fat.” WRONG! You are losing more than fat.
If you do not provide it with food, and thus with calories, it will begin to burn the fat it has stored for just such an emergency.
The problem is, your body can only burn fat so fast. Fat has a lot of energy, but that energy is released slowly. Starving yourself somewhat is no problem if you’re providing your body with some calories.
But if you provide your body with no calories—or too few—it will have to turn to something besides your fat to burn…your muscles.
Large muscles are not essential for life, and protein provides energy much more rapidly than fat does. Your body will burn muscle on any day that you don’t eat. That’s not that big a deal. Your body is well-equipped to handle the occasional day without food, and the minor amount of muscle mass burned on a day you fast is easily restored when you eat again.
However, if it goes on, and you burn all or most of your stored fat plus a large amount of your muscles, your will begin to burn the protein in your organs.
On top of that, your body begins shutting down any “inessential” systems. This includes even your immune system, making you highly susceptible to disease.
If you are trying to gain muscle, look “cut” and healthy, you want to retain as much muscle as possible and lose as much fat, up to a certain point.