Dieting - A Physicist's Weight Loss System

  • This is an extremely effective method of weight loss!
  • The body can use up a LOT more body energy during the night than it does now, simply by your using thinner blankets or sheets during sleeping!
  • This works IN ADDITION to any current program of dietary intake restriction and/or exercise.
  • This also works during the daytime, too, where you might wear thinner sweaters in winter.
  • This is actually NOT such a peculiar idea! In January 2012, some TV newscasts presented a far more dangerous variation of my concept, where they encouraged people to get into ice-filled bathtubs for extended time. THAT is a stupid idea (in my opinion) as it encourages behaviors which might easily cause pneumonia or even death. The opposite extreme has also been in recent news. In August 2011, stories about the Researchers who spend months in Antarctica described where each person needed to eat massive numbers of candy bars and such, because that environment causes people to give off such massive amounts of body heat that they must eat at least 6,000 Calories of food each day!

I have discovered an amazingly simple and easy way in which we might lose weight! Just throw off some of the covers while you sleep! Not all of them, but just some, where you are still comfortable. Sure, attention to the diet is important, and so it exercise. But this simple concept can account for around ONE POUND OF BODY WEIGHT LOSS PER WEEK! That is astounding! People on diets are counting individual calories! They don't seem to realize what tiny amounts of bodyfat that accounts for!

One pound of bodyfat is equal to around 3,500 Calories of energy. This is a well-established fact. It will be important to remember this. So if you are on a diet where you reduce your food intake by ONE HUNDRED CALORIES A DAY, people seem to celebrate! But that represents only 1/35 of a pound of bodyfat reduction per day, a really tiny amount. A primary reason why people lose interest in diets is that you must stay on that rigid food schedule for 35 straight days, to only see A SINGLE POUND of bodyfat having disappeared. The odds are that you did something opposite during those 35 days, where the benefits are wiped out. But even if not, it is hard for people to stay on a very rigid diet for 35 days only to see a single pound disappear, because they actually want to see 10 pounds or 20 pounds or 40 pounds disappear, and we are then talking about YEARS of staying on that super-rigid diet!

By the way, ANY diet or other weight loss system that claims to enable you to "lose many pounds in a week" can obviously not be true! Even if you ate NO food in a particular day, your body (an adult man, a woman a little less) only uses up around 2,200 Calories which is mostly your BMR (basal metabolism rate) plus a few hundred more Calories due to exercise and other physical activity. Therefore, even if you ate no food at all, you could only lose a little over half a pound of actual 3500-Calorie-per-pound bodyfat per day! (Your weight can reduce more than that, but it is nearly entirely due to water content of your body, lost as sweat, urine, or moisture in the breath.) Anyone or any advertising that tells you otherwise is simply lying to you! (see a discussion below)

You might notice that during 24 hours of movement, your body generally only uses up a few hundred Calories. Specifically, in a ONE-HOUR strenuous workout, you cannot expect to burn up more than 100 or 200 Calories. Again, that would involve about 17 or 35 days of such serious exercising to burn up even one pound of actual Bodyfat. Not quite like what all those TV commercials and books tell you!

These comments are to try to explain WHY, no matter how seriously you ever seem to diet or exercise, you just do not see pounds vanish like claimed in the commercials! Now you know why that is.

Your body constantly generates energy, which it needs to power all the systems of your body, heart, muscles, brain, nervous system, etc. After that energy is used to do the many processes, it ALL then gets later given off as heat, in several different ways. Some gets lost by your skin radiating and convecting heat away. More heat is carried away by your warm breath. Your perspiration evaporates from your skin, which gives off additional heat. These things ALWAYS happens!

On average, the total food energy content that you eat/drink is the same as the total energy that your body needs for all of its operations and it is also equal to the total energy that your body gives off after it is done using it. This is called that BMR Basal Metabolism Rate, and for adult men, it is around 2,200 Calories per day. For women a little less. For people of different body types, a little more or less.

During the daytime, you are more active, and so more processes occur inside you, so more energy needs to be processed and then discarded, and so your skin temperature is slightly higher than when sleeping. While you are sleeping, everything slows down BUT DOES NOT STOP!

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Consider that this whole sequence can be affected by any of the three stages. (1) You could eat more or less food; (2) you could do a lot more work or exercise to get your body processes to convert more food/fat into energy; or (3) you might alter the ability of your body to dispose of the excess heat, and also to breathe out more breaths of carbon dioxide. Your body has the capability of adjusting its activity due to differences in any or all of these three areas. Specifically, in a really hot environment, your body can shut down many systems to reduce the energy that needs to be generated, down to a low of around 20 Calories per hour (research data from Frederick C. Hatfield, of ISSA), in order to try to avoid overheating.

We are going to consider the situation for the eight hours each night that we sleep. In a relatively cool room environment, your sleeping BMR (Basal Metabolism Rate) only drops a little from the daytime 100 Calories per hour, down to around 80 Calories per hour. Your body has many processes that it still needs to do, like digestion, operation of the heart, lungs and other organs, thinking as during dreams, etc, which is why the 80 Calories per hour is very common. Your rate of breathing slows some during this form of sleep, but not too much, so it still rids the body of a lot of carbon dioxide each hour.

But a lot of people today use many blankets to sleep under, or they use an electric heating blanket, or they use an electrically heated water bed, or they keep the room extremely warm. Some of these actions can cause the body to HAVE to reduce all its activities down to near that 20 Calories per hour, just to keep from overheating. This extreme slowing of your metabolism causes your breathing rate to greatly slow down, and therefore, your body can only lose a rather small amount of carbon dioxide each hour.

See the point? Instead of your heavily blanketed or hot bedroom body burning up 20 * 8 or 160 Calories while you sleep, if you instead get rid of that heavy blanket and/or cool the room down somewhat (to 66F or 68F, for example), it could be in far more normal operation and burning up 80 * 8 or 640 Calories each night. That difference, of 480 Calories (640 - 160) that you COULD allow your body to NATURALLY burn up, if done over seven days (a week) is around 3500 Calories! (480 * 7) One extra pound of bodyfat will therefore burn itself up (each week) WHILE YOU SLEEP! Is THAT a great diet or WHAT?!

Your sleeping rate of breathing will be several times faster, but you will not be aware of that change because you will be asleep!

A person eats an amount of food each day that contains chemical energy as Calories. We could use the example of a person who has a diet of 2,240 Calories per day. This energy is needed to accomplish many things inside our bodies, primarily digestion, physical activities and mental activities, along with pumping blood and the rest.

Say we are considering a relatively sedentary person, one with a desk job, for example. The ASHRAE Handbook charts indicate that such a person emits around 390 to 450 Btu/hr of heat. ASHRAE is interested in that subject because it related to how much air conditioning equipment would be needed for a sports dome where 30,000 people may be inside! 1 Calorie is equal to 3.968 Btu, so this body heat loss is around 100 Calories per hour of heat lost from the body. This lost heat is exactly the same as the amount of energy the body uses up in basal metabolism. This confirms that an adult person constantly uses up around 100 Calories per hour. One essential purpose of this is in maintaining the core body temperature, which is centrally important to good health.

During sleep, the skin temperature drops a little, and respiration slows somewhat so that heat lost in exhaled breath is reduced, but there is still at least 80 Calories per hour needed (used up) even with the cooler skin temperature. (Note that this is described for a situation somewhat similar to that while working, moderate clothing [and/or covering] in a relatively cool (say 65F to 68F, 18C to 20C) room). This is then a total of around 640 Calories used up while he sleeps. We can confirm these things by adding 16 hours at 100 Calories per hour and 8 hours at 80 Calories per hour for a total of around 2240 Calories, which is in decent agreement with the normal daily dietary intake for an adult man.

As long as he eats 2240 Calories of food and his body uses up 2240 Calories of energy, each day, his weight will stay fairly constant.

Now consider if he sleeps with an electric blanket or lots of heavy covers or in an especially warm bedroom. His body no longer has to generate so much heat to maintain core body temperature. In fact, the body alters blood circulation and changes other things that it can to keep from overheating. Essentially, the body is capable of self-regulating in this way to producing as low as around 20 Calories per hour during sleep. (If it cannot self-regulate low enough, the person starts to overheat, and eventually pushes off a cover!)

(There seems to be research data from Frederick C. Hatfield, of ISSA, that supports this figure of a sleeping minimum of 20 Calories per hour.)

Since his body is now generating 20 Calories per hour of heat, in the eight hours of sleep, he uses up 160 Calories (of energy obtained from existing bodyfat reserves) during the eight hours of the night. By being really cozy in bed, he has eliminated 480 Calories of energy that would otherwise have been used up and radiated away as heat! If we do our addition again, we now have him still eating 2240 Calories of food but now using up just 16 * 100 + 8 * 20 or 1760 Calories of energy. What happens to that 480 Calories that he did not use up? You know the answer! It turns into body fat reserves, because the body chooses to store that energy for some possible future emergency. Well, storing 480 Calories worth of fat every day really can add up! It seems likely that he would gain about one extra pound of weight EVERY WEEK! This seems like an EXTREMELY likely partial source for the overwhelming problem that exists regarding obesity in modern life. (Yes, food choices and quantities, gluttony, are important, too!) Just one year of this pattern could add 50 pounds to the bodyfat of that person! Not even necessarily related to what he eats or how much he eats or how much he exercises! Just the way he sleeps! Isn't that interesting?

The GOOD part is that it is very easily solved and even reversed! By simply throwing off that heavy cover or that electric blanket, or turning down the heating thermostat for that bedroom at night, you can MAKE your body use up those extra 480 Calories every night (as it originally expected to do)! Every week or so, you should now LOSE another pound of bodyfat! Interesting, huh? You don't have to buy anything, or pay anyone, or eat food you hate (although you can still do those things if you wish!)

Even massive workouts at a health club now become interesting to think about! The related web-page linked below (regarding overall thermal efficiency of a human) describes that our "useful work" over an eight hour work shift in a harsh factory environment, is at around a rate of 0.1 horsepower. A serious workout at a gym is generally in this same range, although certain extremely strenuous activities, if done for only an hour, can be somewhat higher. We are going to say 0.15 hp for a one-hour period of a workout. But we note that 0.15 horsepower-hour is around 96 Calories. The human body tends to have a maximum efficiency of around 20%. This suggests that our person is actually using up around 480 Calories in that hour of strenuous workout. (96 Calories of that results in actual "work" like in raising weights or moving water while swimming; and the other 384 Calories is needed by the body to maintain all the internal processes that maintain survival. This increased internal production of heat is necessarily dumped by the body as heat. Some is by radiation by skin that is warmer than the surrounding room. Some is by convective heat loss from the skin to the room air which is cooler. Some is by convective heat loss by exhaled breath that is warmer than the inhaled breath had been. Some is by latent heat loss in water vapor carried away in the breath. Some is by latent heat loss due to sweating.)

See the point? A strenuous hour workout at the gym might use up a total of 480 Calories. In comparison or in conjunction, you could use up just about as much energy (and therefore bodyfat) EVERY night while sleeping, just by throwing off the heavy covers!

(Have you ever wondered why you don't seem to lose significant weight due to working out every day? An hour of strenuous workout might use up 480 Calories, so around a week of those strenuous workouts would be required (7 * 480 or around 3,360 Calories) to use up one pound of bodyfat. You would only measure a difference of 1/7 pound in any one day, too small for standard scales to register. Worse, all that exercise tends to make you hungry, right? So you may actually eat more and gain weight. But at least you will tone your muscles!)

This discussion has not addressed "shivering". That would certainly use up a few more Calories, but we think they would be minimal, not worth the discomfort, and possibly even a health hazard! The idea here is "just a warm enough room or a light cover to avoid shivering". Commonly, people keep a bedroom at 68°F or 65°F at night (20°C to 18°C). The room should NOT be made cooler than that, unless you happen to LIKE it at 63°F or 62°F! So the person would not be particularly uncomfortable, unless that super-warm coziness is considered critically important! There does not appear to be any advantage of making the room any cooler than that anyway, as the body just shuts down blood circulation to the limbs to avoid excessive losses and to maintain core body temp.

A number of sources indicate that a pound of human bodyfat contains roughly 3500 Calories of stored chemical energy (such as Michael Sasek of Synergetic Health). This then implies that the 480 Calories difference due to sleeping with a heavy cover or not would have an effect of around one pound per week (7 * 480 is about 3500 Calories or one pound of bodyfat) in total body weight. That is, by not using a heavy blanket, it seems reasonable that roughly one pound of body weight loss seems realistic each week, separate from any efforts toward diet or exercise.

There is an ISSA Basal Metabolic Rate (BMR) formula:

First, for Men: 1 x body weight (kg) x 24
For Women: 0.9 x body weight (kg) x 24

For a 170 pound man (77 kg), that's 1 * 77 * 24 = 1848.

Next, factor in your approximate body fat percentage. Multiply the result from above by the multiplier factor:

Men 10 to 14%, Women 14 to 18%: 1.0
Men 14 to 20%, Women 18 to 28%: .95
Men 20 to 28%, Women 28 to 38%: .90
Men over 28%, Women over 38%: .85

In the 20-28% group, we would have 1848 * .90 = 1663 Calories per day. This is your BMR. It's your BASE rate.

(Interestingly, this factor demonstrates that bodyfat has an effect of thermally insulating the inner workings of the body. People with more bodyfat need to generate less internal heat in order to maintain necessary body temperature. Skinnier people have to produce more energy to maintain that temperature!)

Finally, factor in your daily activity level. Multiply your BMR by the daily activity level multiplier factor: This essentially converts the BMR up to the ACTUAL metabolic activity of your life!

(These factors give energy consumption rates that are somewhat higher than the ASHRAE official figures regarding heat losses, but they do not affect the general concept of this presentation.)

If our example person was in the light activity category, the actual daily Calories = 1663 * 1.55 = 2578 Calories per day. So, using the ISSA system, our 170-pound man would use up around 2578 Calories every day, and he would need to eat food with that much energy content to maintain constant body weight.

No one can monitor every Calorie they consume each day, but efforts at aiming at a general average can help control body weight. This presentation is simply pointing out that a rather massive effect, about 480 Calories each day, is also probably available.

Note: We have discussed here the ENERGY which gets lost from the body by this procedure. The body must necessarily also rid itself of a larger amount of carbon (or carbon dioxide) in the process of doing this (see the discussion below). Therefore, the rate or depth of breathing during sleep must necessarily increase, to accomplish this necessary function.

Addressing heaavily advertised Weight-Loss and Dieting Programs

IF you take in more Calories (actually kilo-calories or Kcal) in a day than you use up, the excess energy is turned into sugars and fats, and eventually into fats called lipids or triglycerides, to be stored away for a possible future survival need, and you will gain weight. Equally, if you use up more Calories in a day than you take in, some of those existing lipids or triglycerides, fat and sugars is converted back into forms that can become energy, and some of the bodyfat are therefore converted into that work and weight is lost. The premise behind "working out" is closely related to this fact, and it would work to some extent, if it were not that all that exercise often creates a healthy appetite!

It is interesting that enormous numbers of TV, radio, newspaper and magazine ads talk about amazingly fast rates of weight loss, with some diet or some piece of exersize equipment! We tend to consume around 2200 Calories of food energy and use up roughly the same amount each day. It is rare when the difference, either way, is greater than around 200 Calories in a day. It also turns out that the sorts of exercises usually done at Health Clubs in working out, tend to rarely even double our normal body energy consumption of about 100 Calories per hour (thereby burning off only another 100 Calories per full hour of such exercise, again rarely more than 200 [extra] Calories burned off in such an extended workout session).

We note that bodyfat is a very compact source of energy supply (the whole point of it regarding survival!) and a pound of bodyfat contains around 3500 Calories of chemical energy stored in it. This indicates that two or three weeks are often likely necessary (3500 / 200 or about 18 days) to be able to lose even ONE pound of bodyfat! People who try to lose weight by dieting and/or exercise get frustrated at such slow progress! (For success, they must have immense patience and incredible dedication to the effort, both of which seem opposite of modern hurry-up and have-it-now attitudes!)

So TV and magazine and newspaper and billboard ads brag about losing 50 pounds in 50 days or something like that. Think about that. In order to lose 50 pounds of bodyfat in 50 days, it is necessary to lose or use up more than 1 pound every day. And such ads and concepts rarely also even attempt to get the person to also reduce the excess amounts of food they eat which caused them to become obese in the first place! If such a program could succeed, it would mean using up around an EXTRA 5000 Calories of energy from stored bodyfat each and every day. Even if the person did not eating anything at all for 50 days, the body's metabolism could only use up around 2200 Calories each day, where the actual total body weight loss would then be around 30 pounds in those 50 days! (Our bodies have an amazing ability to survive for many days when no food is available!) (By the way, people who go on long religious Fasts tend to lose MORE than this amount of total body weight, but that total loss also includes a large amount of WATER that is also lost in the process.) There is no easy way for our bodies to use up 5000 Calories per day! Do you see why such claims are exaggerations and/or misleading?

There is another way to look at all such claims. People selling such thihgs claim to make bodyfat "melt away" or equivalent, right? Bodyfats are all lipid or triglyceride molecules that are nearly completely carbon, hydrogen and oxygen atoms in complex combinations. You probably know of a basic law of science that says that nothing can either be created or destroyed (Conservation of Mass). Well, those lipids or triglycerides are commonly around 40% carbon. So WHERE does the carbon go? It can't just disappear! It must go somewhere! Can it VANISH in body heat? No, that would not account for the carbon atoms. Could it get excreted? No, because the digestive system is entirely separate from the body metabolic processes. You can rule out EVERYTHING, except for one thing! Your exhaled breath! Virtually the ONLY way that a human body can get rid of carbon atoms is to oxidized them into becoming carbon dioxide molecules, and then send them out of your body as exhaled air! Sadly, bodyfat can therefore never just "melt away"!

So, IF someone claims to cause bodyfat to be used up three times or ten times as fast as natural, they HAVE TO explain how THREE TIMES (or ten times) AS MUCH EXHALED BREATH had to also occur in order to carry the carbon atoms from all those bodyfat lipid or triglycerides molecules away from the body! Otherwise, all those carbon atoms have no easy way of going away!

There ARE a few very minor chemicals that get created which use up carbon atoms, but most of those stay in the body to be used for other purposes, and so they cannot represent actual REDUCTION of CARBON in the body! Those processes also affect VERY small amounts of the carbon, not enough to seriously even need to think about when considering amounts of bodyfat!

By the way, you might see the connection here between when you do serious exercise and then have to breathe heavily for a while? In doing strenuous exercise, you DO use up some bodyfat molecules (but a disappointingly small amount of them. We will shortly see in the Technical paragraph below that even when we exercise hard enough where our breath is TWICE normal, that only removes the carbon from around 1/1100 pound of bodyfat per minute. A full hour of such strenuous exercise and we can remove only around 1/20 pound of bodyfat!). Due to the requirements of the exercise, the body naturally accesses some of your energy supplies, first, the sugars, which are most easily accessed fast, but then the bodyfat stores. As those (sugar or) lipid or triglyceride molecules are oxidized, carbon dioxide molecules are formed, which get carried to the lungs and then exhaled with the next outgoing breath. If you do TWICE as much exertion, then twice as much of the lipid or triglyceride (bodyfat) molecules get oxidized, and twice as much exhaled breath is needed to carry all that carbon away from the body! Now you know! (You also breathe more heavily to get more oxygen INTO the body, to be able to do all that oxidization of all that carbon into carbon dioxide. The body has an immense number of unique chemical reactions, and we have greatly simplified the matter here!)

This brief discussion is intended to show you that virtually ALL the carbon that can leave your body must leave by your exhaled breath, and that all the impressive claims of flashy advertising which claim otherwise are simply not credible. IF some program causes you to BREATHE MORE HEAVILY, either deeper breathing or faster breathing or both, THAT WILL directly increase your body's ability to get rid of undesired bodyfat. So the next time you see any of those ads on TV or elsewhere, THINK about whether they are describing any credible way where your breathing is increased. If not, there is no realistic reason to spend money to buy what they are promoting!

On a more technical level, each INCOMING breath draws in air which is at the natural 0.038% of carbon dioxide, and each outgoing breath contains around a maximum of 4.4% of carbon dioxide. When sitting, we breathe around 12 times per minute and each normal breath is around 0.5 liter of air. This all means that in each minute of normal breathing, we exhale around 0.25 liter of carbon dioxide. This means that each minute, we each exhale around 0.5 gram of carbon dioxide, or around 1/1000 of a pound. (In an entire year of normal breathing, we each exhale around 500 pounds of carbon dioxide!) This includes around 1/3500 pound of actual carbon atoms per minute. If they had come from normal foods (averaging 40% carbon atoms), that represents around 1/1400 pound of food which would disappear during that minute (of normal breathing). At around 2200 Calories per pound of average normal food, that means that around 1.6 Calories of food (or other energy sources) gets used up every minute.

If the carbon atoms had come from lipid or triglycerides bodyfat molecules instead, a far more concentrated source of stored energy, only around 1/2200 pound of bodyfat would need to get used up during that minute (of normal breathing). This situation would occur if the person went on a fast without eating any food, or if the person exerted himself more than could be supported by the food recently eaten. At 3500 Calories per pound of bodyfat, that again means that around 1.6 Calories of bodyfat would get used up every minute. Since a day includes 1440 minutes, that again would account for the 2,200 Calories of energy that our metabolism needs to use up every day to keep us alive. This then proves that each minute of regular breathing involves exhaling the carbon atoms from the equivalent of either 1/1400 pound of average food or 1/2200 pound of bodyfat. That is essentially the ONLY significant process the body has of removing carbon from itself, which it does in order to supply energy for its many processes!

This web-page is based on the energy analysis of another web-page, Human Being - Thermal Efficiency - the Physics.

This presentation was first placed on the Internet in July 2006.

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C Johnson, Theoretical Physicist, Physics Degree from Univ of Chicago