Friday, November 22, 2013

Ketogenesis: The Japanese Anime of Metabolic Pathways

Today I come to you with a lesson in Biology. To be specific today's lesson is about Metabolism. Metabolism is defined as the sum of the physical and chemical processes in an organism by which its matierial substance is produced, maintained, and destroyed, and by which energy is made available. Why am I coming to you with a lesson in metabolism? I have always struggled with my weight, ever since puberty I've been like an elevator with my weight, up and down. At my highest I weighed 130kg and at my lowest I went down to 88kg - that variance of 40kg is the weight of a small Asian woman.

Post-work lazyness is also heavily ingrained within me. I would much rather sit, drink beer and watch a movie or play a video game than go to the gym but I also ssure you I'm a total endorphin addict, I love that feeling you get after a 15km run, its initiating that run that I struggle with. After a stressful day at work I sometimes toy with the idea of hitting the treadmill for an hour but then I realize I'd much rather spend those 60 minutes slaying dragons or mowing down an army of enemy pirates with an AK47 (which is clearly much more fun).

Mowing down said army of pirates with an AK-47 in a delightful blue and green tropical setting - Far Cry 3
The reason why my weight fluctuates so much is directly due to my eating habbits. They (by they I mean those fitness experts who don't have real jobs but have great big bleached teeth) say maintenance of a healthy state is 80% diet and 20% exercise, well my diet can really go to shit very very quickly. When it does I really don't eat a lot but I eat bad. I eat much healthier since coming to Singapore three years ago than i ever have but still my diet could always use improvement. I decided to do some research into other ways (non Gym related) that I could use to lose weight or maintain an acceptable equilibrium. This my friends leads me to the topic of this post.

The biology surrounding metabolic pathways in homeosapiens is very complex indeed but with the strategic use of constrained language (idiot speak) one can make it easier to understand. This is what I will attempt with my subsequent words.

What are metabolic pathways?

In simplest terms 'the metabolic pathway' is cellular respiration. This is the process by which a cell breaks down macromolecules in order to produce energy. In even simpler terms this is “fuel in, energy out”. The energy gained from burning fuel (food) is used to power all the processes going on in our bodies. These include the building of proteins, DNA, fat, as well as the overall maintenance of the human body (homeostasis) and energy dependant mechanical processes such as muscle contraction (movement).

The 'fuel' we need to maintain life takes three basic forms: carbohydrates, proteins, and lipids. Humans are capable of burning all three of these fuels, but do so at different times, rates, and under different circumstances. The human body (like myself) is expert in maintaining life at the lowest calorific cost.

If you still don't get it think about going when you go to work in the morning; your car is the carbohydrate pathway, your bicycle is the lipid pathway and walking is the protein pathway.

What are Carbohydrates?

Carbohyrdates or carbs are one of the most abundant types of fuel available to human beings and in very simple terms come in two types: 1) Simple and 2) Complex.

Simple carbohydrates (monosacharides) are found in refined sugars (like the white sugar you would use for baking cakes). You will also find simple sugars in fruit and milk, unlike chocolate bars which contain added sugar foods containing natural sugar also contain vitamins, minerals and fibre. This is the most accesbile form of energy for the human body, it takes the least amount of time and energy to break this food down into glucose for immediate use by the body.

Complex carbohydrates (disachardies and such) are also known as starch. Starches include grain products such as bread, rice, pasta and potatoes. Refined complex carbohydrates such as white rice and pasta have been processed which results in loss of nutrients and fibre. The best form of complex carbohydrates are vegetables, green leafy vegetables which require much more energy to breakdown than any monosacharides. 

Whole lot o' carbs

What are lipids?

Not to sound more intelligent than I actually am the next paragraph is a direct extract from the mighty Wikipedia: Lipids are a group of naturally occurring molecules that include fats, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, phospholipids, and others. The main biological functions of lipids include storing energy, signaling, and acting as structural components of cell membranes.

What are proteins?

The word Protein comes from the Greek word 'Proteios' which other than sounding cool means primary or first. Protein builds, maintains, and replaces the tissues in your body. Your muscles, your organs, and your immune system are made up almost entirely of protein. The best sources of protein are beef, poultry, fish, dairy products, eggs, nuts, seeds, black beans and lentils.

If you remember any of your biology or chemistry from school then I'm sure you'll recall the words 'Amino Acids', well Amino acids are the building blocks of protein. They are required for every metabolic process within our bodies.

The metabolic queue at a nightclub

So now that we have some very basic knowledge about the three main fuel sources of humans we can proceed to the really interesting stuff, the way in which your body extracts energy from these fuels.

For this