Not Fair – Part 2

In my last blog I talked about how it isn’t fair that eating only a few extra calories can pack on the pounds. The flip side of that equation, however, is that if you cut back a few calories and are patient, you can lose the weight.

Have you ever thought about the fact that you expend energy all the time but only eat every now and then? In between eating, your body has to use energy previously stored so that it can continue to power the chemical reactions that we call life. Your body has two different types of energy storage systems. One is fast acting and readily available. The other is harder to access but can store much more energy. Think of it as the difference between the food you have at home in the frig or pantry and the food that is available at the grocery store.

The primary quick response storage unit consists of glycogen which is stored in the muscle cells and in the liver. Liver glycogen is mostly reserved for the brain. In most people glycogen can provide somewhere around 2,000 calories of energy or about one day’s worth. This also happens to be about the number of calories that it takes to run 20 miles which is why many runners hit the “wall” at that point in a marathon.

The body’s long-term energy storage is fat. There are 3500 calories available per pound of fat. Suppose you have 20 pounds of fat. That amounts to 70,000 calories of energy, a 35 day supply. That pretty amazing and complex system allows us to survive in conditions where food may not be available for extended periods of time, not usually a problem for us but a problem in past societies and in some places today.

Losing weight then is a simple matter of eating less energy than you expend. If you do that, your body will use the stored fat for energy. If your expenditure of calories exceeds your intake by 500 calories per day, then in a week you will lose a pound.

You are not a perpetual motion machine. Your energy has to come from fat or food. You decide.

Keep Running!