healthnut

Jeff Novick has an interesting blog on metabolism and aging. It’s the physical activity that slows down metabolism as one ages. Younger people have higher metabolic rates because of higher lean body mass. As people age, they tend to to “retire” from their physical activities; thus is the reason lean body mass and aging will correlate.

http://www.jeffnovick.com/index.php?option=com_myblog&show=Move-It-Or-Lose-It-Even-If-You-Are-70!.html&Itemid=261

Now depending on who you talk to, metabolism can be a VERY, VERY, VERY complex subject. On a cellular level, it basically means the movement of energy via transports. Cells eat and secrete waste. See link below for animation.

http://highered.mcgraw-hill.com/olc/dl/120068/bio02.swf

Now here are some interesting notes from a biochemical nutrition class.

1. If you eat too much carbs, the liver steps in and help packages the extra carbs as lipin (fat).
2. Stress and diet can increase insulin resistance. If insulin goes down, then glucose goes up.
3. High protein and high fat can slow the absorption rate of carbs.
4. The more muscle, the higher the BMR (basal metabolic rate). The BMR is a rough estimate of your metabolic rate at rest, ie. sleeping. It is the minimum number of calories per day you will need to keep your weight constant.
5. Men have a higher BMR because of higher lean body mass. Hint: They are the ones who always want to help us carry things. Now we know why.
6. Muscles burn fat. Calories do not. Because women let men carry their things, women tend to store more fat in their bodies. As people age and become more adaptive to the sedentary lifestyle, they will lose muscle mass. Lower muscle mass means less efficiency in burning fat.