Metabolism and other elements within your body

[Will]

I posted this on OcUK recently and I thought I'd share it here

I researched this for a little bit, and dug my nose into nutrition, science and other sort of books.

Glycemic index (GI)

GI is a measure of: "the rate at which food is broken down and absorbed into the blood stream". The higher a food's GI, the quicker this happens. IME/IMO foods with low to medium GI should be chosen, to help minimise insulin response (spikes), in doing so, this will increase the amount of fat used as a fuel source rather than hard earned muscle.


Insulin (something else I bore people with! )

Insulin enables the storage of glucose in the muscle and the liver. However, it also directly inhibits the use of fat as a fuel source (remember low GI as I was saying before?). It is nigh on impossible to burn fat with high insulin levels. Carbs are the direct impact the release of insulin (though most foods to a certain extent create a release of some kind). This level of release is directly related to their relative GI. There is, however, another hormone which counteracts the levels of insulin in the body (woohoo!), as well as enabling the body to burn fat more efficiently. Glucagon (I'll go on about it in a sec). Insulin also suppresses the effect of adrenalin and noradrenalin, reducing the bodies ability to metabolise fat.

Cortisol

Cortisol is a catabolic (muscle degenerative) stress hormone. Although it acts as a natural analgesic too (and it's what helps you wake up in the morning), it very much has a negative effect on protein synthesis (my favourite topic! ). High levels of coritsol are linked to a loss in muscle tissue. However, like all things, this is a double edged sword; because, as your muscle mass decreases, your metabolic rate also decreases (as I've been rabbiting on for years ). Thus, as your metabolic decreases, fat levels increase - simples, eh? Fat also has the ability to convert the inactive (safe) form of cortisol to the active form. Active cortisol promotes fat storage in spots around your body, however, cortisol deposition is more evident around the abs/lower belly. Fat around there is often used as an indicator and precursor of heart disease. It doesn't mean you will have it, but it's a start of a potential warning.

Fat (the most overused and misunderstood word!)

There is more to fat than most people realise. Most people think of it as something that is around your belly, or lard stuck to the end of bacon or meat and is generally a hugely negative component of modern life. However this much misunderstood compound has a lot of interesting parts to it. A whole book/thesis could be written on this - so let's try and keep it simple! Fat produces an enzyme called aromatase (heard of it? If any of you have looked into naughty juices you will have heard this name being mentioned many times). Aromatase is bad news as it converts testosterone to oestrogen (we don't want this at all! This can also lead to Gynecomastia in the long term - aka, bitch ****).

Oestrogen has the ability and a tendency to increase body fat deposition around the body (there are certain parts, back, thighs predominently however these are not exclusive but common).

Still with me? Ok, so more fat deposition = more fat. Therefore more fat = more armoatase! Ooop, this means more oestrogen! Which means more fat deposition, which means..... yup you got it, it's a vicious circle. Great eh? Lovely!

If you thought that was the worse you could get it actually does more in the long term... bad things. If and when oestrogen rises and gets to a significant elevated level (this is different for every person, and it gets super complicated) this leads to negative feedback through the HPTA. Which is bad. The HPTA is the Hypothalmic Pituitary Testicular Axis. This causes a drop in endogenous (made by our bodies) testosterone. Testosterone is what we need to help us be big strong men - so as you can imagine, this ain't good! So the fatter you get, you will have lower testosterone, more opestrogen, and then we go back to that vicious circle again.... This potentially could lead to higher levels of body fat, heart disease, diabetes, potentially impotence, depression (very very common according to the stats) and many other things.

However this is just fat on your body, not fat that one eats. We all know about that already - this is just the compound within our bodies.

Thyroid

The body's temperature should be around 36C and 37C, it's the thyroid hormone's job to regulate that body temperature. A person with high fat, will have a larger surface area, and also have more insulation insulation as a result. (Basic thermodynamics, about losing heat/absorbing heat). Therefore owing to this principle, the thyroid has to compensate, else they will be overheating and therefore die. This strain lowers T3 and T4 thyroid hormones, which lowers their thyroid production. It's not always because they have a bad thyroid that they're getting fat, it's potentially because they are fat that their thyroid ain't working as it should! (Clearly there are genuine Thyroid conditions which cannot be ignored, however these are the exceptions that make the rules, the basic vicious circle principle is correct.)

Cellulite (a girl's worst nightmare!)

Let's clear up the myths:

• Caffeine causes it to increase
• Somking causes it
• Lymphatic system
• Alcohol and other "toxins"
• A host of other old wive's tales

I'm sure you've heard all the "cures" - I won't get into them, because ostensibly cellulite is just a form of fat.

The tell tale "skin pattern" is caused by the following:

1. Uneven spread of fat receptors
2. Putting lots of fat tissue into a tight lattice of tendons, muscle and skin cells basically makes it squeeze in between the tendons and cells creating that pattern
3. Having too much body fat basically... it's just the way it is!

If you want to get rid of cellulite drop your bodyfat - that's all there is to it - sorry if you were expecting more science!

Glucagon

I mentioned glucagon earlier. This is a hormone that helps the body in moving the remaining glycogen stores (do you need an explanation of glycogen?) from the liver and muscles to turn it into energy. When glycogen levels become low, glucagon triggers something called the carnithine shuttle, which in turn promotes the use of stored fatty acids into energy.

This really is the best and only natural way to make your body use fat as fuel, and thus reduce your body fat. Which is why something like HIIT is perfect for this sort of activity. Certainly first thing in the morning. As mentioned in the first paragraph it replaces the primary fuel (carbs) with the secondary (fat). It really is that simple.

Our bodies are fascinating, and love synergy, so when one hormone gets too high, others compensate to either bring it low, or to bring a balance in your body. As such, it creates more and more chain reactions. It's quite clever really.


Growth Hormone (GH) (the natural stuff obviously! )

As you've no doubt heard me metion before, GH is abundant in low insulin environments, insulin suppresses GH. GH is highly lipolytic, but more importantly, strengthens your immune system (hence why newborns have such high levels). Unfortunately as you get older GH reduces - or more accurately, the lowering levels of GH are part of the ageing process! If you can keep these levels as high as you can for as long as you can - the better you will be!