- Personal Health Information & Self-Help
A Definition of Metabolism
The word metabolism comes from the Greek word for change metabole.
It is generally accepted there are two categories of metabolism, catabolism and anabolism.
In animals catabolic metabolism is a process called cellular respiration which involves oxidising and turning organic substances or large molecules, in the form of food, into a usable form of energy. Which is then used for movement or heating.
Anabolic metabolism uses the energy from catabolism to make, or synthesize substances within cells, for example, proteins.
Metabolism as a chemical process is dependent on temperature, pH, and nutrition, Metabolism can also be a computational process.
Set Points and Metabolism
Metabolism is quite possibly regulated by set points within the brain.
A set point is a point, which is selected in the brain, quite possibly the hyperthalamus, around which functions cycle sometimes within quite tight parameters. For example a temperature set point for a human body during the day time is 37C, the temperature is allowed to cycle above or below this according to internal or external factors, but when all environments are comfortable and operating optimally the temperature returns to 37C.
Do you know if your metabolism is?
Can Metabolism be Measured?
Metabolism can be measured, it is the rate of energy expenditure that is measured, but it is not an easy or accurate process. It may be the respiratory quotient is a more reasonable method of measurement where the basal metabolic rate can be estimated from carbon dioxide production
Measuring metabolic rate however, is not easy to do. The laboratory equipment is expensive and relies on measuring carbon dioxide exhaled as a measure of metabolism. This process of measuring metabolism is however prone to errors, because different fuels (foods) might produce different energy amounts for the each amount of carbon dioxide measured.
The ideal metabolic state is one in which an individual can switch easily between a state of high metabolism to a state of low metabolism.
What is a High or a Low Metabolism?
As our bodies make energy, we use it to keep us warm or to do things. On occasion our bodies can make more energy than we need, this then becomes excess energy, or a high metabolism. We can use this energy to warm up further and so, instinctively, we might remove clothing to cool down, or use the energy up by being active, in some cases the onset of hyperactivity can be the result of this excess energy.
It is much easier to control metabolism than body temperature. If a person, for example has hyperactivity due to a higher metabolism, simply dressing a little uncomfortably warm for a few days might down regulate the metabolism.
With a low metabolism there is a failure to make enough energy, this can make us feel sluggish and prevent us from being active or doing what we want to do. Low metabolism can also prevent us from keeping warm. When metabolism is low we might feel cold or tired, again instinctively we might be less active or pull on more clothing to warm up.
People can be likened to engines in terms of 'wear' and an approximation of the fuel used. This process is often known as metabolic damage.
Both people and engines wear in approximate proportion to the fuel consumed, a process called "metabolic damage". In animals, the higher the metabolism, the faster is the aging process.
There are some benefits to having a high metabolism. Competitive activities, like sports athletes and perhaps the hunter gatherer equivalent activities are performed better using the highest metabolism achievable. In this competitive environment the participants train themselves to push their metabolisms as high as they can, it is easy to recognise people with high metabolisms as they wear sleeveless clothing when others are wearing warmer clothes.
There are some thoughts that thin people have higher metabolisms. Heat loss is proportionate to the surface area of the skin and heat production is proportionate to the body mass. Thinner people have much less mass whilst having a similar surface area and so if everything else is equal they will need to have a higher metabolism to make more energy to replace the lost heat. Thin people would probably also wear more clothes to avoid being uncomfortable when their metabolism has a shortfall, these extra clothes would then bring their metabolisms back down.
An ideal compromise which would give the benefits of the use of an occasional high metabolism burst without accelerating the aging process, would be to train the body to be able to alternate quickly from a state of high metabolism to a state of low metabolism and vice verse.
With a low metabolism, or energy shortfall, life can be difficult. Simply trying to keep warm or trying to be active whilst feeling tired can be a chore. wearing a lot of clothing can sometimes help, and these people often wear a lot of clothing during the summer, they also tend to be inert, less active, in order not to do very much conserving energy.
One benefit of reduced metabolism is reduced metabolic damage and this means aging more slowly, but inactivity is the trade off.
Can a Low Body Temperature mean a Low Metabolism?
A normal daytime body temperature or 37C or 98.6 is pre programmed and selected by the brain, the brain pops the body to this temperature in the mornings after awakening from a selected sleeping temperature of 36.3C or 97.4F.
If for some reason this process is damaged, the brain fails to select the higher day time temperature and the sleeping temperature remains at that level all day long. maintaining a lower sleeping temperature requires very little energy as function process are minimised, however, if a low temperature is selected during the day, increased metabolism, or more energy is used to try to keep the body warm and active.
The need to keep warm and active, when at a lower body temperature means using higher levels of adrenaline, and so more adrenaline has to be produced during the daytime. Adrenalin is thermogenic and no only do low body temperature people use this heat to keep warm but they also need to remove the excess generated heat, they do this by moving to colder environments or removing excess clothing, sometimes the excess heat is radiated out through hot extremities, hands or feet.
The results of making and removing the excess heat whilst continually adjusting the environment involves using a higher metabolism than would normally be required at a normal body temperature of 37C or 98.6F.
How to raise metabolism
Raising metabolism can be easy and can be achieved by just wearing less clothing. The process requires gradually wearing less and less clothing. During the process, the heat loss would accelerate, and the heat generated would accelerate at the same level at the same time, this would could easily raise the metabolism to whatever level is required. The end product of a very high metabolism is not ideal due to the inevitable and consequential metabolic damage.
There has been and is still a bit of confusion about metabolism. It is possible to look at metabolism from more than one perspective:
A medical model perspective which endeavours to explain the brain or more specifically the hypothalamus in terms of chemical reactions and hormonal activity based on the fundamentals of homeostasis, which I accept.
The other well known perspective is more computational. This is the metabolism that I subscribe to in terms of the mechanics and practical applications, indeed having applied the process of up regulating my own metabolism slightly by wearing a few less clothes for the summer, but come the winter I will be wrapping up warm and reducing my metabolism!