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The Scientific Jargon
Metabolism is the chemical reaction based around the energy that occurs in living cells. There are catabolic reactions that get the energy and there are anabolic reactions that use this energy to construct components of cells like proteins.
This is quite a simplified explanation and scientists will probably be telling me that I need to go into more detail and that the whole process can’t be explained in a couple of lines. However I am not trying to get a Nobel prize and this is a fitness and diet blog, so I am sure that there are many more of you that will be glad that I don’t go into too much detail. Put even more simply: metabolism is based around energy taken in and used within the body to perform basic tasks and cell construction.
Metabolism is interesting to us because body fat is actually stored energy formed when we take on more energy than we use. For our purposes we are actually interested in something that is called the Basal Metabolic Rate (BMR). BMR is the amount of energy we use whilst at rest with no external or internal influences. This means that you are at complete rest but awake and your digestive system is inactive (this requires approximately 12 hours of fasting – Beeble). As BMR is the measure of the amount of energy our bodies consume in this state, we can use it to calculate how much energy we need from our foods, enabling us to eat within our limits and not to excess (or so the theory goes – Beeble). The most accurate way to measure your BMR is through gas analysis (I am hoping that it is from our breath and not from the other end – Beeble).
Influences that can increase metabolism
- Increased muscle mass
- Increased cardiovascular exercise
- An increase in stress levels
- Stimulants
Influences that can reduce metabolism
- Decreased muscle mass
- Lack of exercise
- Increase in age
- Menopause
The result of the BMR test is shown in kilo calories (kcals – Beeble) and it is by far the largest expenditure of energy in the body. So if you know what your BMR is then you can quite accurately judge how many kcals you need to get from your diet to maintain or reduce your body fat levels. It is fairly easy to work out with a calorie counter and as food’s energy is also measured in kcals you can really keep an eye on how much you should be eating. Approximately 70% of the body’s energy expenditure comes from BMR 20% from exercise and physical activity and 10% from the digestion process. The organs that are associated with BMR and their individual energy expenditure are as follows:
- Liver 27%
- Brain 19%
- Heart 7%
- Kidneys 10%
- Skeletal Muscle 18%
- Other Organs 19%
I guess you could look at this and think: “What is the point of exercise if it only burns off 20% compared to the 70% that the body is doing all by itself?” Well, take another look at the table above and you should hopefully notice something. Let me explain. Liver burns off 27% which is by far the largest proportion, the next largest is the brain at 19%; however these percentages are fairly static. You are not going to burn off significantly more energy by over working your brain and working out some long mathematical equation (although that would explain why a lot of mathematicians are slim – Beeble). If you look again at the table above there is one that you can change and that is your skeletal muscle. By exercising you will increase your muscle size and therefore increase the percentage that it would be. In turn this will increase your BMR which has one of two results: either you will lose excess fat quicker even at rest or you can eat more without gaining extra weight.
Summary
This is the scientific backing to what we already know and that is a healthy whole food diet combined with cardiovascular exercise and weight training will reduce the amount of energy our body’s store and increase your metabolic rate which in turn will reduce excess body fat which, also, in turn makes us healthier, live longer and gives us a better chance against illness and disease.
There are a lot of weight loss drugs out there that say they can increase your metabolic rate and some of them probably can. However they are stimulants which have a side effect of putting a lot of stress on your organs like your heart. Also their effect is tiny compared to the effect of increasing your muscle mass. By looking for the easy way out we can make ourselves ill and not benefit from a true lifestyle change.
By taking up exercise and in particular weight training, you will reap benefits that no drug can offer and that is a promise. It is hard work and it isn’t always a fast result, but you will feel so much better for it and it will last a lifetime.
What to do now
Well I don’t believe it is that easy to get your gasses measured but there is a calculation that can work out your BMR which although is not that accurate it is far more accurate than saying 2000kcal a day for women and 2500kcals for men (this is always quoted as the average – Beeble). To measure your BMR click here. Now take your results as your daily allowance and make sure you consume slightly less than this everyday and you will lose weight. You can measure how much you consume through food and drink daily by using a calorie counter like fitday.com.
Good luck with it and please let us know how you get on by going to the comments section below.
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October 2nd, 2007 at 3:08 pm
[...] Muscle gain has to be increased, but that does not mean that we have to all become bodybuilders. Far from it, you can gain muscle mass without bulking up and it all comes down to your training techniques, which of course is what this post is all about (picture a long distance runner rather than, the far more muscular, sprinters body). Just a quick explanation: it is vital that you understand the importance of increasing your muscle mass, which means that the more muscle you have the higher your metabolic rate. Basically your body needs to be able to maintain its new weight. If you just reduce your body fat but don’t increase your muscle mass you will find it very difficult to maintain that new weight. I have written a post on this subject which covers it in more detail, read it here. [...]