Food Energy & Weight Loss

Below is an excerpt from Part Two of

The 2004 Multi-Diet

by Anderson A. Anonymous, M.D., Ph.D.

Carbohydrate is for Burning

As we pointed out above, your body’s normal fuel mix is made up of mostly fat, much less carbohydrate, and small amounts of amino acids. But the body can easily change that mixture if it needs to burn off a huge excess of dietary carbohydrate (that big spaghetti dinner you just ate ).

Most people believe that when you eat too much carbohydrate, the body just turns it into fat. This is not really correct (except under unusual circumstances). Research over the last 15 years has demonstrated that although humans do possess the enzymes necessary to convert carbohydrate to fat, the body does this only when it has no other alternative. Actually, this conversion rarely happens at all, because most of the time the body has at least two better uses for that carbohydrate. The first of these is to immediately use it as fuel to power the various cells that need it. The second is to store it as glycogen. (Glucose is also needed in very small amounts for “nonoxidative” purposes.)

When your body gets done doing these two other things, there is rarely any carbohydrate left to be turned into fat. In other words, burning carbohydrate for fuel and storing it as glycogen are each strongly preferred over converting it to fat. Why is this?

The probable reason for these two carbohydrate preferences is that converting carbohydrate to fat is an “energetically expensive” process. It requires about 25% of the energy in the carbohydrate just to turn the other 75% into fat. That 25% is “conversion overhead”—wasted energy—because it never gets to be used for fuel by the body. On the other hand, if the carbohydrate can be used immediately, then all of it’s energy (100%) gets to be used for fuel. If it is stored as glycogen, about 95% of it can (eventually) be used by the cells (5% is used to convert the rest).

Obviously, either of these alternatives is far less wasteful than converting it to fat. (The Beast may be only a primitive sub-mind, but in 500 million years, God and evolution have succeeded in teaching it a thing or two. One of these things is that wasting 25% of a scarce resource like energy is not a strong survival trait.J) In any case, your body will always try to burn the carbohydrate you eat and/or convert it to glycogen before it converts it to fat.

You will recall that we said earlier that the body normally burns a mixture of fat, carbohydrate, and protein. In order to be able to burn more of the carbohydrate without wasting it in fat conversion, the body shuts off fat burning almost entirely until it’s burned up any excess carbohydrate you’ve given it. It also fills up its glycogen stores in the liver, but these are very small (under normal circumstances about 300 grams, which is about three-quarters of a pound). Only when these two things have been done and there is still too much carbohydrate does the fat conversion process begin. Physiologists have demonstrated that it takes several days of massive carbohydrate overeating (the kind that will almost make you sick) before any serious amount of fat conversion actually happens.

Right now, some people (but not you) may be saying to themselves “This is great! I can stuff myself with carbohydrates and still not gain weight!” More good logic! (Still wrong, though. ) To begin with, you’re trying to lose weight—and that won’t happen if you shut off fat burning. Further, there are very few foods that have only carbohydrate and no fat in them (even celery is about one-half of one percent fat by weight.)

When you eat anything that has both fat and carbohydrate, the fat immediately gets stored in the fat cells until it’s needed for energy. And it will never be needed for energy as long as you are stuffing yourself with carbohydrate. So you’ll get fatter anyway.

There is another extreme conclusion that some people tend to jump to: “I just won’t eat any carbohydrate so my body will have to burn nothing but fat.” Yet more good logic! (But by now you know it’s wrong too.J) There are two important issues that apply here. The first is that even though carbohydrate’s main use is as energy, it is also required for several other things. We have already discussed its use by the brain, nervous system, and blood cells. Additionally, a small amount of carbohydrate is required to allow fat burning to proceed normally.

Converting fat into energy is a biochemical process with several steps. During one of those steps, a substance (pyruvate), which is created from carbohydrate metabolism, is required. If no carbohydrate is available, the fat burning process stops at that step. The name of this abnormal state is “ketosis”. Energy is still being produced in this state (though probably not the normal amounts), so you won't get sick or die, but it is an unpleasant and stressful state to be in. Naturally, The Beast is wide-awake during ketosis.

The second issue, as we have said, is that the brain, nervous system, blood, and some other cells want glucose for energy and will wake up The Beast if they don’t get enough.

In fact, some of these cells need glucose so much that your body will begin to make glucose out of muscle protein and glycerol if you aren't eating enough carbohydrate. As we have seen, losing body protein is a bad thing on a diet. The Beast will be wide-awake if you don’t eat enough carbohydrate.

Just in case you’re getting discouraged by the apparent contradictions here, keep in mind that there is a BIG difference (huge, in fact) between “getting enough” carbohydrate and getting as much as you usually get. (All that chocolate cheesecake…J.) Ideally, we want to eat enough carbohydrate to keep blood glucose levels at the low end of the normal range where there’s enough for the tissues that need glucose but not enough for the tissues that would rather burn fat anyway. (The Beast knows how to make this distribution properly.)

One other point is worth mentioning. Over the past two decades, many diet-book authors have jumped to one or the other of the above extreme conclusions about carbohydrate (i.e. “eat a lot” or “don’t eat any”). Then they have tried to create weight loss techniques exclusively around whichever conclusion they’ve jumped to. Some of these techniques work for some people for some amount of time. But they always stop working for everyone eventually. This, in my opinion, is the source of most of the controversy about “high-carb” or “low-carb” diets. Both approaches are partly right and partly wrong and wholly incomplete. Success in dieting requires a balance of the right kind of carbohydrate in the right amounts and no more. When you achieve this balance (among the others discussed in this book) The Beast goes to sleep and losing weight becomes easy. We discuss how you determine the right kinds and amounts of carbohydrate in more on… carbohydrate.