In which I think about calories and metabolism

Yesterday I was thinking about weight loss, more than the abstract "I want to lose weight" to the "But how exactly do I go about it?".

In case you don't know, there is apparently 3,500 calories in 1lb of fat (I'm not sure how 'they' worked this out or even who 'they' are, but I'm going with it.) This means to lose 1lb a week, you must somehow remove 3,500 calories from your normal diet.

This equates to 500 a day. But 500 calories cut out of your normal diet every day is a lot!

The daily guideline amounts are like 2000 calories for women and a bit more for men, but I think 2,000 calories is a lot, you know? I only noticed when I started using myfitnesspal, and it counts them for me. Even before I was trying to cut out calories, I was only eating around 1,700 calories a day. My allowance now is 1,200.

So technically, I should be losing 1lb a week, right?

Wrong.

The fact is your body gets used to running on a smaller amount of nutrition. Your body is a wonderful complex machine that has many mechanisms for staying alive, one of which is to adapt to new environments. So eventually the weight loss will taper and eventually stay constant, you won't lose anymore. And that might be a good thing, I know that there'll come a time (fairly soon I imagine) when I won't want to lose anymore weight, I'll be more focused on building my strength and my muscles but I'll be quite happy with the size I am and stick with it.

But what if you hit the plateau and you still want to lose?

It's fairly simple really, you can't have a healthy losing weight campaign without exercise. So instead of cutting out 500 calories from your diet alone, why not try just 250 calories, but burn 250 calories exercising instead?

250 calories really isn't much, which is something I've learned over this little weight loss jaunt I'm on. Here are just some of the ways to burn 250:

• Walk 8,000 steps. This is about 30-45 minutes depending how quickly you walk, and of course the quicker you walk the faster you'll burn the calories
• Cycle for 15 minutes, walk/jog for 20 minutes in the gym
• Do 100 jumping jacks
• Row for about 20 minutes

The possibilities are truly endless, they're just the ones I can think of off the top of my head.

Then this whole losing weight thing led me on to thinking about metabolism.

In every healthy article both online and in print it's all about 'boosting your metabolism' and I can see where they're coming from. But I don't quite get it.

Metabolism is every process in your body (basically), it is both the breakdown and building up of complex molecules to form cells, proteins and everything else your body needs to function. Metabolism involves the breakdown of what you eat into the little amino acids, sugars and triglycerides that your body can use to make cell walls, proteins, DNA and everything else that makes you. It is the oxidation of fats into triglycerides that can be used to fuel the body, leading to a reduction in fat stores. It is also the process of respiration; the combining of oxygen with glucose to form compounds that can be used in a complex series of reactions to form ATP (adenosine tri-phosphate) which is the form energy takes in the human body.

So speeding up your metabolism, increasing the rate at which molecules are broken down and reused, should be a good thing, right?

I'm not so sure.

The fact is metabolism isn't just how quickly you burn fat, and if you aim to increase your basal metabolic rate through exercise (which I could find no evidence for) then you're increasing everything else too. You're increasing the rate at which drugs are processed through your body, making whatever doses you take effectively lower, or potentially spiking the dose depending on the form it takes. You're increasing the rate at which neurotransmitters such as serotonin, noradrenaline and dopamine are broken down in synapses - which could be either good or bad depending on your disposition.

But you'll also increase the rate of respiration. Now respiration is a brilliant thing, its what keeps us alive. However, the breakdown of oxygen leads to something called oxygen free radicals. These are atoms with broken electrons, basically, and they're the reason you age. They're the reasons cells die, hair thins and wrinkles appear. It's why everyone says 'EAT ANTIOXIDANTS!' to slow the aging process. I'm not ashamed to admit that I'm not looking forward to seeing those wrinkles appear, and if eating chocolate and keeping my metabolic rate at the speed it is now will prevent that, then I'm going to do it!

So I'm all for speeding up my fat metabolism, but I'd rather not end up with wrinkles before my time, thanks.