I hate to be condescending but, if you will excuse me, I must explain a second grade subject here which relates intimately to diet, exercise and weight control. Some of you may be offended by this retreat back in time but we really learned a lot in second grade which is applicable to weight gain and loss. I will term it by a name we didn’t learn in grade school but the principles are the same. I will call it the “Law of Mass Action.”
The law of mass action is: Input – Output = Accumulation
In second grade we learned about addition and subtraction. I learned it when the teacher brought a box into school and emptied out a bunch of apples on her desk. She said to the class, “now class, this box is empty. With my right hand I put in two apples, with my left hand I put in two more apples and with my right hand I put in another three apples. How many apples are in the box.” I said “eight.” Was I right? No, the correct answer is seven (2 + 2 +3 = 7). Well, I really wasn’t good at math until college.
The teacher, a Sister Florence, who thought I was really stupid and irreverent, said, “now class with my right hand I take out two apples and with my left hand I take out one apple. How many apples are in the box?” I didn’t say anything. Someone else, a girl named Laura, answered, “four, Sister Florence.” Was Laura correct? Yes, as usual, Laura was correct (7-2-1 = 4).
How simple that is to us now. At least I hope. And yet some of us fail to recognize this law of mass action in the human body. The human body is much the same as the box. It has ways of gaining substance (like apples or pounds). It also has ways of losing substance (like feces and urine). Let’s look at the gaining as inputs to the body and losing as outputs from the body so that it fits the law of mass action.
The inputs to the body include some relatively simple things to measure such as food and drink. We can weigh the amount of these things before they go into the body. We might eat four pounds of food in a day and drink five pounds of fluids. We have put in nine pounds of matter or substance. But that really doesn’t include some difficult things to measure such as gasses inspired and absorbed by the lungs. In a day this is a significant amount of matter. We inhale about 12 times per minute a volume of about 500 ml. There are 1440 minutes in a day so we inhale about 8.6 million milliliters per day (12 x 500 x 1440 = 8,640,000 ml). Inhalation, as we shall discuss later, is partially offset by exhalation. But the issue is that inhalation and exhalation vary considerably depending on what the person is doing and, to make things difficult, is complicated to measure, requiring sophisticated tools and cumbersome attachments to the body or enclosure in a specially designed room. This makes the weighing of input to the body very laborious and impractical for the general public.
The outputs form the body are even less desirable to measure. They include feces, urine, sweat, and expiration with its concomitant water loss from humidification of the breath. And, of course, some relatively rare things like cutting hair, amputations, and bleeding. Most people are not willing to weigh all of their feces and urine, do not have the equipment to measure expiration, and surely cannot measure the sweat produced over a day.
One may believe that respiration is balanced so that we can cancel them out in the equation. It is not. We do not exhale the same quantity of gasses we inhale. There is a respiratory quotient which determines the relationship between inhaled oxygen and exhaled carbon dioxide. One would believe that they are balanced, but for complicated physiologic reasons beyond the scope of this essay, the balance is not balanced on a 1:1 ratio but depends on the food stuffs in the diet. For example, a diet high in carbohydrate has a respiratory quotient of about 0.8. That means that the ratio of oxygen inhaled is 0.8 times the carbon dioxide exhaled. And as the diet changes so does the respiratory quotient. What a nightmare to try to approximate or to measure.
So, although the law of mass action applies to the human body it is really a method to determine what is happening to the body if we use substance (weight, mass, molecules) as the units. For this reason, nutritionists this century elected to use a different unit of measure, one that is more easily used in their fields of study. Unfortunately, their unit is not well-understood by the layman. It is the Calorie, a unit of heat. That’s right, it is a unit of heat, not a unit of weight and not even a unit of energy. A Calorie has no weight!
A Calorie as used in nutrition is 1000 calories used in physics. So a Calorie is actually a kilocalorie. A calorie used in physics is the amount of heat needed to raise one gram of water between 14 and 15 degrees centigrade. A Calorie or kilocalorie as used in nutrition is 1000 times as large, so it is the ability to raise 1000 grams or a kilogram (approximately one pint) of water the one degree centigrade between 14 and 15 degrees. Suffice it to say in this essay I will use the nutritionists Calorie or kilocalorie exclusively.
A Calorie is only a measure of heat not of energy. There is a movement in nutrition to use joules instead of Calories. Joules are a physicist’s way of measuring energy. But because Calories and joules are linearly related the changing of measurements from Calories to joules is only a purist movement. We can say, although not technically correct, that a Calorie is a nutritionists unit of energy.
The body is composed of many different substances including proteins, carbohydrates, fats, vitamins and water. All of these substances have atoms attached to other atoms to form the molecules I have named. The atom to atom attachment is called a bond and it requires energy to break that bond. Some bonds, however, once broken allow more energy to be captured than what was necessary to break the bond in the first place. This occurs in the human body when hydrogen nuclei are transferred along a cascade which captures energy and stores it in a high energy molecule called ATP (adenosine triphosphate). Our bodies then use the energy in ATP to allow us to breathe, walk, exercise and stay alive.
Our food and drink is also composed of proteins, carbohydrates, fats, vitamins and water. The first three, protein, carbohydrates and fats, have usable energy in the form of Calories once eaten, digested and assimilated. The energy we consume in the food and drink can be measured in Calories. Charts have been prepared which list various foods, the size of portions and the Calories contained in the food. The food, like an apple, were placed in what is called a bomb-calorimeter and burned by an electric current of known energy input in the presence of pure oxygen. Water around the chamber collects and measures the increase in heat. The results are in the Calories of the chart.
One word of caution is in order. If you look at three different charts for a piece of apple pie you may well get three different Calorie contents. First check the serving size. It may be different. But three different sources reporting on a 4.7 oz piece of apple pie may report 350, 375 or 450 Calories. The reason has to do with the amount of shortening or butter used, the type and ripeness of the apples, how much sugar was put in the pie, and etc. None of the charts should be taken for absolute correctness, only for approximation and comparison with other food stuffs.
As an example a 4.7 oz piece of apple pie has 350 Calories but a 4.6 oz baked apple (without sugar or coating) has 120 Calories. This comparison may well aid in selecting a dessert depending on the needs and preferences of the consumer.
Only food and drink have significant calories and they are much more easily measured than inhalation. This grossly simplifies the measuring required and allows the layman to approximate inputs into the law of mass action. The nutritionist uses the Calories in food and drink as the sole units for the law of mass action. This is good but, as we shall see later, it leads to confusion when a person hardly eats any calories in a day and yet gains two pounds.
Now let’s change our attention to outputs. There are several caloric outputs from the human body. First, just plain staying alive and maintaining the normal 98.6 degree Fahrenheit temperature of the body requires Calories. This is the basal metabolic rate (BMR), i.e., the amount of Calories required in 24 hours to maintain life and temperature. It is measured by a six minute test in a special chamber after nothing to eat and no exercise in the previous twelve hours. Most people never have this test because it is expensive and there is a fairly good way to approximate BMR. Nomograms in many textbooks allow the calculation of BMR for people with normal temperatures (98.6 degrees). If you want to know your BMR I refer you to the book “Nutrition, Weight Control, and Exercise” by Katch and McArdle. You must know your age, height, weight and gender to make the calculation. If you want just send the data to me and I will send you back the results.
Second, and really important for the martial artist, is exercise. The BMR only measures what it takes to keep you alive for 24 hours. My BMR is 1825 Calories per 24 hours. It takes 1825 Calories to keep me alive at a temperature of 98.6 degrees for 24 hours. But as soon as I start to do any kind of exercise, even sitting up to write on this computer, I start to burn more calories than under basal metabolic conditions. All exercise calories need to be included in outputs of the law of mass action calculations.
The more activity you do the more calories you output. You don’t have to get out on the track and run. You can walk, vacuum, chase the kids, weed, get up to change channels on the TV rather than use the magic remote, wash dishes by hand, go for a bike ride, do a kata, train in a karate class or any of many different activities. All of these activities have energy outputs which have been measured. Most of Caloric outputs are reported in the book I mentioned by Katch and McArdle. I have also given you a simplified quick method of measuring running, bicycling and swimming Calories in the essay on exercise.
Third, this is the hard one, is that digestion itself requires energy and feces contain energy which has not become available to the body. It is not practical to try to measure these at home. It is generally approximated that 10% of the measured calories in food and drink are not used. This is an approximation for several reasons. It takes more to digest protein than it does to digest fat or carbohydrate (hence the rationale for the dangerous high protein diet). A person eating a high protein diet will require more calories to digest the protein and so has a higher output than the approximated 10%. But before you go out and put yourself on one of these atrocious high protein diets please be advised that high levels of protein are damaging to the kidneys and liver. People have been known to develop kidney failure requiring hospitalization and dialysis from ingestion of high protein diets. Some people have died on this diet. They are dangerous.
When a person eats a well-balanced diet, she can expect the digestion and feces output Calories to be about 10% of the measured input Calories. If the woman is pregnant she will increase her efficiency. If the woman is on or has recently been on a rapid weight lost diet she will increase her efficiency. But, luckily, if she is not under any of these special circumstances the 10% approximation factor usually works rather closely.
So on the inputs we have
• food Calories/24h
• drink Calories/24h
And on the outputs we have
• BMR Calories/24h
• total exercise Calories/24h
• 10% of total input Calories as an approximation of digestion and excretion
Using approximations of the above inputs and outputs, the law of mass action will aid in determining the direction and rate of weight change.
Let’s take an example:
• food = 2000 C/24
• drink = 200 C/24h
• BMR = 1800 C/24h (obtained from nomogram)
• walk 1 mile = 100C/24h
I – O = 2000 +200 – (1800 +100 + 10% (2200)) = +80Calories/24h
According to these approximate calculations this person will gain weight at a very slow rate, about one pound in 45 days if these measurements are exact. The measurements are never so exact that one can say with any degree of certainty that this person whose accumulation figure is so small will gain or lose weight. Too much depends on approximation. The food calories are approximated as we saw in the example of a piece of apple pie above. The BMR is approximated from a temperature which is rarely 98.6 degrees in all people. The exercise output Calories are approximated also. So why do the calculations?
The reason is that this person is not going to change weight rapidly in any direction. This person has an approximation that she is stable. If she wants to watch her weight daily she can rest assured she will have a good idea of what is happening in her body as long as she maintains the same program and checks it with daily weighings. Over a month period this person should not gain or lose much weight. Daily, however, there may be a lot of fluctuations, the subject of the next discussion.