How to use Science to Lose Weight #2 – carbohydrates

So your body runs on glucose. Glucose belongs to a class of chemicals called carbohydrates. And before we go any further we must look at what carbohydrates are and how they work.

Carbohydrates are very sensibly named – as their most basic structure is carbon + water. That is, their basic formula is CH2O, and every carbohydrate has this basic formula, but only in multiples of 6. So glucose is C6H12O6.

Image result for glucose

This 6 – carbon unit is the most basic structure possible, so it is referred to as a monosaccharide.

Table sugar (sucrose) is C12H24O12 and looks like this:

Image result for sucrose

So sucrose is a disaccharide, and is composed of two monosaccharides.

And the sky’s the limit – saccharide units can be added together to infinity, like chemical lego blocks. An example of a polysaccharide is starch:

Image result for starch

So a complex carbohydrate like starch is made up of many glucose units. Before your body gets fuel, therefore, it must break these complex molecules into its component glucose molecules.

But the real question is – how quickly does this happen? If the breakdown happens quickly, then your blood is flooded with glucose.  This can cause a serious medical condition called hyperglycemia, so your body removes the excess glucose by releasing insulin into your blood from your pancreas.

This has two long-term effects – firstly it causes you to put on weight, as the excess sugar is converted to fat. But it can also cause you to become a diabetic, as your pancreas eventually gets overloaded and just gives up – this is why fat people are often also diabetic.

The rate at which a food releases glucose is referred to as its glycemic index (GI), and is the single most important factor in determining whether the food is fattening or not.

Now, this results in some weird outcomes. For example, look on the label for Nutella and you’ll see it’s loaded with sugar and fat – but it’s low in GI. And the reason is simply that the fat slows down the rate at which the sugar breaks down.

And this is a pattern – often the fibre in something slows down the sugar absorption rate, so you are far better, for example, eating whole fruits rather than fruit juices.

For further reading, have a look at Eat Yourself Slim, which explains all this in fine detail

How to use Science to Lose Weight #1

The human body is the most complex chemical reactor in existence. Ultimately, the amount of fat on your body is the result of multiple factors, many of which are poorly understood in the marketplace.

The purpose of this series of posts is to explain what those factors are, so you can make informed lifestyle decisions decisions when choosing how and when you exercise, and what type of food you eat

This has been a particular issue for me for many years now, as I am one of the small number of men to have suffered from an eating disorder. Eating disorders are almost exclusively the domain of women (97%). I am one of the 3%.

If you are reading this article to quickly get to the bottom line (as I often do) I will very quickly summarise the conclusions I have come to, and the rest of this article and the ones that follow it will explain the logic behind those conclusions

In summary:

1. The concept of calories in, calories out is wrong. The number of calories a food contains doesn’t mean much,

2. The glycaemic index of a food is everything.

3. When looking at a food label the amount of sugar a food contains is far more important than the amount of fat it contains.

4. When selecting foods based upon the type of fat they contain, where possible consume monounsaturated fats.

The first issue to is how the body gets its energy to operate. In other words, where does the body get its fuel? Your car gets its energy from either petrol or diesel – what is the fuel that your body runs on?

The answer is that it is mostly glycogen (a form of glucose). I say “mostly” because under some circumstances the body has the ability to switch to different fuels, but for the purpose of this discussion we can stick with glucose as the main source of fuel.

In simple terms there are two main of glucose – carbohydrates and fat in extreme circumstances muscle tissue can be broken down to provide glucose, but this is not the normal mechanism of operation.
In my next post we’ll consider this fuel system in more detail, and start to understand how we can manage it to control our waistlines.

Food and Weight Loss #5

So how do you stop your body going into starvation mode and piling on fat?

The answer is simple – don’t starve yourself.  You do not have too go hungry to lose weight.

The biggest breakthrough in the area of dietary intake in recent years has been the advent of the glycaemic index.  Essentially, it measures how quickly a particular food is converted to glucose.  As we have seen, your body can only tolerate a certain range of blood glucose levels.  If it’s too low, you run out of energy, and if it is too high, your bloods injects insulin, which converts your glucose to fat.

This is the reason why so many overweight people are diabetics.  They have been eating so much sugary food that’s their pancreas (the organ at produces the insulin) gets worn out.  That is, it has been so bombarded with simple sugars, it is simply worn out from all the insulin it has had to produce.

So toss out your calorie counter, and get a list of foods and their glycaemic indices.

If you eat food that has a low glycaemic index, which are usually complex carbohydrates, your body will break down the carbohydrates as required to produce the glucose.  So this stops you putting on weight.

But how do you lose weight that you might already have?

Well, if you are eating well, lots of filling vegetables, meat, and complex carbohydrates, your body will feel no need to store fat, and so will attempt to shed the fat that it has.

The only issue here is that the energy contained in fat, since it is more condensed, is not so easily acquired as the energy in carbohydrates.  In other words, fat cannot be metabolised as quickly as carbohydrates.

So all you need to do is choose an activity that doesn’t require quick energy – something like walking.

If you are walking, your body has time to break down the fat to produce the required energy, and there is absolutely no exercise anywhere that is as good for fat loss alone as walking.

So there you go – don’t starve yourself, eat food that is low in glycaemic index, and walk a lot, and the fat will just melt away.

Food and Weight Loss #4

Both complex carbohydrates and fat may be converted to energy. If we are going to lose weight, we really mean we want to lose fat, so the real question is – how do we make sure that we convert fat to energy, instead of converting carbohydrates to energy?

One obvious answer, and one that has been behind every failed diet that people have ever been on, is to say “don’t eat any carbohydrate.”

And at first glance this seems to make sense, which is why this approach has been so popular for so long. Obviously if I take away one source of energy – carbohydrate – my body will use the only source left – fat.

The problem with this approach is that your body is an exceedingly complex chemical reactor with billions of chemical reactions going on every second – and the notion of energy in – energy out is far too simplistic.

In real terms, if you cut down your intake of carbohydrates, the body goes into starvation mode.  That is, it battens down the hatches, and says “it looks like food may be in short supply – I better preserve what reserves I have.”

To do this it does two things.  Firstly, it slows your metabolism.  This means that it slows the rate at which it uses energy.  This is of course is the very last thing you want.  The other thing it does is to convert what fuel it does have to the most efficient form for storage, which is fat.

Why is fat more efficient for the storage of energy?

Let’s look at their chemistry and we’ll see why:

Let’s look at the formula of say stearic acid (a fat): C18H36O2

A similar sized carbohydrate (about the same weight) would be C8H16O8

Do you see the difference? The fat is made up almost entirely of carbon and hydrogen, whereas the carbohydrate has much of its weight taken up by oxygen.

Your body, since it is now completely taken up with efficiency of storage says “I don’t need the oxygen – I can get it from air later on.”

So since the fat stores more carbon for a given weight than the carbohydrate,  that’s what you all body does with the food it gets.

So limiting food intake may mean you lose weight, but it’s mostly water.  Your percentage of body fat actually has increased.  And what happens is that when you get down to your desired weight, and start to eat “normally” again, your body now says “at last, some food – quick – store it away as fat before the supply dries up again.”

This is why people who diet often fluctuate and experience the horror of seeing weight go back on that they have just taken off.

So how do you avoid that happening? Stay tuned.

Food and Weight Loss #3

Many things are complex carbohydrates. Paper and wood for example, but you can’t eat them?

In terms of food, complex carbohydrates are generally starchy in nature, and there is no greater battleground than breakfasts cereals.  Let’s compare the information panels of two supposedly healthy breakfast cereals and see what they tell us – Weet-Bix and Vita Brits.

Weet-Bix is 67% carbohydrate with 3.3% sugar.  Vita Brits is also 67% carbohydrate but only 0.4% sugar.

Products with sugar this low are very rare.  Unfortunately our palate is used to sweet things and likes sugar in most things.

Stated simply, the Vita Brits is the best source of complex carbohydrate I have come across, although Weet-Bix is also pretty good.

So what’s so important about complex carbohydrates anyway.?

Well, we’ve seen that how our body runs on glycogen as fuel.  As it happens, there is only a certain level of glycogen that they body can tolerate.  If it gets below this, you essentially run out of fuel – a phenomenon that athletes (marathon runners in particular) refer to as “hitting the wall.”  – Where you lose all your energy, and even standing up and moving a few paces is an enormous chore.

If your blood glycogen gets too high, however, that can also cause problems, and so your body will have to remove glycogen.

It does this by supplying insulin, which essentially converts the glycogen to fat.

Now if glycogen can be converted to fat, then it makes sense to see that fat can be converted to glycogen.

So there are two potential sources of fuel (fat and complex carbohydrates).  If we have sufficient complex carbohydrates on board, our glycogen levels never get too high, and the body simply breaks down the complex carbohydrates as required, and fat doesn’t enter into the picture.

So in an ideal world we’d all eat food which was low in sugar and high in complex carbohydrates.

But in the real world that doesn’t happen of course – we eat too much sugar, it gets converted to fat, and we put on weight.

So how do we get rid of the fat, and cause it to be broken down?

More tomorrow.