The concept of a rubber bag – a new way to lose weight


Diets and different meal planning contradict the key rule of weight loss: if you eat more calories than you burn, you gain weight; if you eat fewer calories than you burn, you lose weight. Considering the problem of weight loss, the man can be compared with a balloon.

Look at your body, reduced to a rubber bag.


What goes in

“What goes in” is everything you eat and drink. Humans, like bears and raccoons, are omnivores—we can eat just about anything, and as long as we get a reasonable variety, we’ll be O.K. You don’t see a ‘coon stalking away from an overturned garbage can because the contents are low in calcium, nor a bear turning up his nose on finding the sandwiches in your picnic basket aren’t made with the latest trendy low-sodium lecithin-enriched oat bran bread. There’s no reason you should be obsessive about food either. Since we’re efficient food processing machines, it’s possible to reduce all the complexity of food to a single number that gives the total energy the body can extract from it—the calorie. The essential thing you need to know about what goes in is the total number of calories you eat in a day. All the rest are minor details.

What you burn

“What you burn” is the number of calories your body uses to provide the energy for everything you do, from heartbeats and breathing to running a marathon. The daily calorie requirement varies quite a bit from person to person depending on size, shape, basic metabolic rate, and degree of physical activity. A rough estimate of calories per day can be obtained by multiplying the ideal weight for your height and body type by a number based on your level of physical activity, ranging from 11 for a pure couch potato to 17 for a person engaged in heavy physical labour or strenuous exercise on a daily basis.

The following tables give estimates of the calories burned per day for men and women at their ideal weight, based on height and body type. The lower number is based on a level of activity characteristic of an office worker who does not exercise, and the high number assumes a moderate degree of physical activity, either as part of your work or through an exercise program. No table like this can be precise—use these numbers only as general guidelines. As you gain control over your weight, you’ll determine precisely how many calories you burn every day.

Height in these tables is your barefoot height. “Frame” is a measure of the robustness of your skeleton; people vary in this regard from the extremes of “fragile wisp” to “hulkin’ bruiser.” If you aren’t sure where you fall on that scale, don’t sweat it. As you can see from the table, the variation based on your level of activity and other factors accounts for almost as much as your frame size.

Daily calories burned: Men


Daily calories burned: Women


The odds are the number of calories you burn every day will fall within the range given in these tables based on your sex, height, and build. This number is of surpassing importance to anybody interested in controlling his or her weight, yet few people are aware of how many calories they burn every day.

What comes out

This isn’t a glamorous topic, but it’s worth considering briefly to complete our understanding of the rubber bag. Every day, you put in some quantity of food and drink. For the most part, your body efficiently disassembles these complex substances into their molecular constituents and makes them available to power the cells of your body. As in any chemical process, there’s a residue of waste, and your body excretes this in the well-known ways.

As an omnivore, your body is very efficient. You can use all kinds of odd stuff as food. Conversely, the substances your body can’t use—the discard pile of the chemical card game of metabolism—are genuinely nasty stuff; the sooner you’re rid of them the better.

Unfortunately, as you bring your weight down to your personal optimum level, the reduced quantity of food you’re eating and the odious chemicals released as you burn up excess fat create a tendency for these poisons to stay inside the rubber bag. Means to ameliorate this situation will be discussed, tastefully I hope, later on.

Inside the rubber bag

Intake, burning, and excretion determine, in large part, how you look, how you feel, and how many years you’ll live. They do this because, through simple arithmetic, they control the contents of the rubber bag. Living, as we do, inside the bag, it’s worth understanding how we’re affected by these processes, then using that understanding to gain control of them.

Assume you eat just enough every day to meet the needs of your body. What goes in is broken down into the molecules to power your body and the result precisely equals what you burn. The residue, what comes out, is discarded to make room for the next day’s food.

This is the condition of stable weight. The entire purpose of this book is to allow you to attain this state. Regrettably, many of us have spent most of our lives oscillating between the following two situations.

Too much goes in

You eat too much. “How could I have finished that entire pizza?” “Those doughnuts cried out, ‘Eat me!’”. When what goes in exceeds what you burn, your body has left-over nutrients floating around in the bloodstream.

We evolved in a world where the normal conditions of life were hunger and cold. On those rare occasions the body enjoyed a feast it, like the prudent squirrel, made provisions for the hard times that would surely follow.

Fat cells are the body’s equivalent of a piggy bank. Fat cells sit on the banks of the bloodstream and, whenever they see excess food, snatch it out and build molecules of fat to stuff in their little cellular storehouse. Each fat cell is, in essence, a little rubber bag: when it sees too much food it snarfs it up and expands.

When this goes on, the larger rubber bag expands: you gain weight.

Too little goes in

You skip a meal, or decide that a scoop of cottage cheese is a wiser choice for lunch than a double beef bozoburger with bacon, guacamole, and cheese.

Before long, the energy-distributing molecules in your bloodstream start to become scarce. Your body starts slowing down to adjust to the situation. You may feel cold, since less energy is available to be burned. Your stomach starts sending telegrams to central control, “Hey, what happened to lunch?”

As the bloodstream becomes depleted in energy, the fat cells notice this and respond; now’s the time to draw down the reserves. Perhaps the boss is stalking a mammoth and doesn’t have time to scarf up some fruit and berries along the way (or maybe Monday Night Football’s gone into overtime and the fridge is forgotten in the heat of the moment—the world of the fat cell is a simple one, hardly cognizant of such modern problems). Individual fat cells begin to tap their storehouses and release energy into the bloodstream to ameliorate the shortfall.

When this goes on, the rubber bag contracts: you lose weight.

Seizing control

Understanding how a system works is the first step in controlling it. Thinking of yourself as a rubber bag may not be glamorous, but it casts the realities of weight control in stark contrast, dispelling the myths and misconceptions that collect around the subject. Compared to most systems engineers design, this one is pretty simple. Let’s look at how to control it.

The first step is identifying what we want to control. Well, that’s obvious: the goal is control our weight. Our weight is just the contents of the rubber bag.

So, what are the inputs to the system? Again, simple. There’s only one input: how much we eat, measured in calories per day.

What are the outputs from the system? Almost as simple: how much we burn, again measured in calories per day, and what comes out. But since what comes out is for all intents and purposes simply the discarded waste products from processing what’s been eaten and, in any case isn’t subject to control, we can ignore it.

Thus we’ve simplified the rubber bag even further, to the following system:figure302

Now we’re getting somewhere! Calories in—calories out: both readily calculated. You get calories in by adding up the calories of everything you eat in a day: good old “calorie counting.” Calories out, the calories you burn in a day, can be initially estimated based on your sex, height, and frame size using the above tables for men and women. Later, you’ll be able to refine this estimate as you monitor your weight.

To determine whether you’ll gain or lose weight—whether the rubber bag will grow or shrink—just take the number of calories in, what you eat, and subtract the number of calories you burn. If the number’s positive, you’re eating too much and the excess calories will stay in the bag; you’ll gain weight. If the result is negative, you’re burning more calories than you’re putting in; the bag will shrink as the reserves stored in fat cells are drawn down to meet the body’s energy needs; you’ll lose weight.

To complete our understanding of the rubber bag, we need but one more fact: a number that relates an excess or shortfall in calories to pounds on the scale. That’s given by the number of calories of energy stored in a pound of fat: about 3500 calories per pound. (Fat is really remarkable stuff when you think about it from the standpoint of biochemistry rather than belt size. Life has discovered, in fat, an extremely compact and efficient way to store energy. We often think of sugar as “pure calories,” but a cup of sugar contains only 750 calories. A cup of lard, essentially pure fat, contains more than 1800 calories, almost two and a half times the content of sugar. Is it any wonder flaky pie crust is purgatory in a pan for anybody with a weight problem?)

If, over a period of time, the calories in the food you eat exceed the calories you burn by 3500, you’ll put on about a pound. Conversely, if you reduce your food intake so that you burn 3500 calories more than you eat, you’ll lose about a pound.

Please reread that last paragraph. It contains essentially everything there is to know about weight control. All the rest are tools, techniques, and details, important ones to be sure, but useless unless you first understand the system. Any tools that achieve the same end, balancing the calories you eat against the calories you burn, will have the same results. (You can dig a ditch with a pointed stick, a shovel, or a backhoe. The result is the same, but you can get the job done faster and with less effort by using the best tool. Still, don’t confuse the shovel [the means] with the ditch [the objective], as most diet books tend to.)

Note the phrase “over a period of time,” in connection with a calorie excess or deficit. One single event: eating a half gallon of ice cream by yourself, right from the box, at one sitting, or going 36 hours without eating as you drive the Cannonball, doesn’t have the impact of a consistent calorie excess or deficiency over an extended period of time.

Once you understand these simple facts, the realities of weight control can be reduced to calculations you work out in your head or on the back of a napkin (a particularly appropriate place for them!). Assume you’re male, 5’11” barefoot, with an average build. You burn in the vicinity of 2200 calories a day. As long as you eat about that much every day, your weight will stay the same.

Suppose you start putting in an extra 250 calories a day. That sounds like a lot, but consider the following:


Savoury Snack Calories
Ice cream cone 220
Doughnut, glazed 225
Beer, 2 cans 220

These little compensations for life’s vicissitudes can add up. Indeed they do…to the tune of an extra 1750 calories per week based on a daily excess of 250 calories (250×7=1750). The weekly surplus of 1750 calories equals half the calories in a pound of fat (3500/2=1750). As week gives way to week, you’ll find you’re gaining about half a pound a week. Two pounds per month. About 25 pounds a year, by which time none of your clothes will fit, you’ll look awful, be depressed about the situation, and feel unable to get a handle on it unless you’ve grasped the simple arithmetic at the heart of the problem.

But consider the flip side of this calculation. Passing by any of the treats listed above, or its equivalent in other foods, hardly constitutes starvation or survival rations. And yet, simply by eating that little bit less every day for a year, you can subtract 25 pounds from your weight in the space of a single year (assuming you weren’t gaining weight before).

We’ll look at these kinds of calculations in more detail when it comes planning your weight loss, but first let’s consider the two sides of the rubber bag, what you eat and what you burn, from the standpoint of the control you can exert over them.

What is more important: sports or food?

How to increase the number of burned calories ? There are two ways: you can increase calorie consumption or to speed up metabolism. And the first and the second can be achieved through the exercises. Apart from the fact that the sport burns a certain number of calories, it also speeds up the metabolism, allowing you to burn more calories in idle mode. That is, working out an hour in the gym, you continue to burn more calories.

A small problem is that the sport also increases appetite and you can easily burn 500 calories in the gym, and then, eat 700 calories, thereby reversing the result of training. Here is a small list of activities:

running – 600 calories;
Walking – 300 calories;
Swimming – 400 calories;
Fitness – 500 calories.

Going for fitness 3 times a week, you can increase calorie consumption by 1500. In the month by 6000. What does it mean? For a month you will burn 660 grams of fat. Only symbiosis of power and sport can create a truly meaningful and correct result. Neither the food nor the sport alone can not do it.

Food and fact

The rubber bag view of the body and considering only the calorie content of food is obviously oversimplified. There is a difference between eating a varied diet and chowing down on a cup of lard and sugar once a day. Programmers know this instinctively: they balance their daily menu among the four major food groups: caffeine, sugar, grease, and salt.

In reality, food satisfies two distinct needs of the body. The first is for energy. A substantial amount of energy is needed just to maintain a constant body temperature and keep the heart, lungs, and the rest of the body’s mechanisms running. The energy consumed by a human body is comparable to a 100 watt light bulb. Food also supplies the raw materials the body uses to manufacture all the chemicals it needs, including those needed to build new cells.

From the standpoint of energy, almost any food will do; you can assume that all foods with the same calorie content are interchangeable. Eating the right mix of food only becomes important when you consider food as raw material. For the most part the body breaks food down into small molecules composed of carbon, hydrogen, oxygen, and nitrogen and then manufactures what it needs from these building blocks. However, certain structures in the body require other constituents. For example, iron is needed to form the hæmoglobin that carries oxygen in red blood cells, and calcium forms the matrix that strengthens bones. In addition, there are a number of complicated organic molecules our bodies require but cannot, for one reason or another, manufacture. These raw materials, minerals and vitamins, must be furnished or else the body begins to develop deficiency diseases such as scurvy and rickets.


Human beings are the most intelligent form of life on Earth and, as far as we know, the only sentient beings in the Universe. From the neck down, however, we aren’t much different from bears or raccoons—we’re omnivores—we can eat just about anything and turn it into energy or, alas, if we eat too much, fat.

From an engineering standpoint this is a simple system. We have virtually no control of what comes out; that’s just the waste products of the factory. We have little effective control over what we burn: in theory our bodies are at our command but the constraints of modern life sorely limit the extent we can exercise.

Consequently, the only real control we have is over what goes in: what, when, and how much we eat. Weight control can be reduced to a very simple matter of arithmetic. Total the number of calories in the food you eat per day, averaged over a period of time. Take the number of calories you burn per day, roughly the same for everybody of your sex, height, build, and level of activity. Subtracting the calories burned from the calories eaten gives excess calories per day. This number times thirty is excess calories per month.

A pound of fat is equivalent to about 3500 calories. If you eat 3500 calories more in a month than you burn, you’ll gain a pound that month. If you burn 3500 calories more than you eat, you’ll lose a pound. All the weight you gain or lose is the consequence of these simple numbers.