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.