Overeating doesn't cause fat gain?

Many people are tired of trying to lose fat, only to fail.

There are also many who are enjoying long term fat loss success.  What's the difference between those who succeed and those who struggle?

There are many who are saying they are on a low calorie diet and also exercising, yet they can't lose fat.  There are media articles suggesting that there is a mysterious cause of fat gain, other than eating too much.  There is growing popularity in believing that the adage calories in, calories out, is over-simplified, and a calorie deficit doesn't cause fat loss in a significant portion of people.

Intersting.

Before I take you through a few fat loss studies, I'd like to first go after the idea that calories in, calories out is over-simplified.  I don't see that.  Sure, that phrase is a summary phrase, and within that context I can see how a person might like to say that level of reductionism doesn't do justice to the entire process. But to claim that by virtue of the simplicity in the phrase, therefore the entirety of energy balance is also somehow not accounting for complexity, is misleading.

I've gone over the details of fat loss here.  That's a lot of detail.  That's what calories in, calories out is referring to.  The actual ingesting and elimination of atoms, the molecules that make up what we eat.  For many that might seem like a stretch because we're used to looking at a plate of food, and used to breathing, but seldom do we contemplate the reality that yes, we are eating molecules of carbon, hydrogen, oxygen, and nitrogen, and exhaling carbon dioxide and water vapour, and urinating out H20 and nitrogen.

It's true.  We can measure the molecules we eat, and the molecules we eliminate.  If we eat more molecules of food than we need for energy, we store the excess as molecules of fat (carbon, hydrogen, oxygen).

That's fairly complicated.  "Yeah but what about metabolism!?"  That is metabolism.  We metabolize molecules we eat, and we eliminate the chemical by-product.  Yes, we actually manipulate electrons and protons to make energy compounds our body uses to run our cells.  That's metabolism.

If someones metabolic needs for the day is 2000 calories, and someone else's is 1700, nothing changes in terms of the energy balance equation.  If the 2000 calorie person eats more than 2000 and the 1700 person eats more than 1700; both have consumed more food than they need.  In the case of an athlete or very active person, if total needs for the day was say, 4000 calories, and on that day 4500 calories was consumed, the excess is stored as fat.

Keep that up and ongoing fat gain is the result.  But what if there really is something we don't understand yet.  What if there really is a significant percentage of the population that somehow doesn't fit this model.  If this is true, we should see this influence in fat loss studies.

What would that look like?  In study after study we would find a significant portion of the study subjects not losing fat when placed on well accounted for, controlled and measured calorie deficit. This quotient of subjects should be prevalent as it is statistically unlikely that through pure random chance all fat loss studies all over the world somehow only capture people who don't succumb to unexplained fat gain or have fat loss resistance.  No such results are occurring in fat loss studies, and I go over this later in this article.

If there really are people who exercise more in addition to eating less with a net calorie deficit, and still gain fat or don't lose fat, where are they getting energy from, and where are the measurements showing that energy that would otherwise be used as fuel is going to fat instead?   There are no studies showing this, and there is currently no consensus that there is an independently confirmed pathway for "unexplained fat gain", other than eating too much.

It's important to realize that we know things like; ATP synthase, a protein structure that makes ATP (the energy molecule our cells use), rotates at about 8000 RPM, and makes one molecule of ATP every three rotations, and that each rotation requires one proton, and that those protons come from the complex biochemical processes starting with digestion and ending with molecules of food broken down to their tiniest parts.

You see, we actually do have a very solid grip on energy metabolism, right down to the flow of electrons and protons.

If there is unexplained fat gain due to metabolic disturbances that is accounting for pounds and pounds of fat gain, then we should be able to easily measure this, since, we already know how to measure this.

Is that complicated enough?  Because that's calories in calories out.

What if someone doesn't know any of that?  What if a person is experiencing difficulty in losing fat, and someone tells them, or they read an article that tells them; their fat gain is because of a mysterious and unavoidable quirk of metabolism?  I can see how convincing that could be.

That's why I write these articles in this way. It's known, but not a common topic of discussion, that atoms, molecules, and spinning ATP synthase structures are intricate parts of our metabolism.  But this isn't as romanticized or as intriguing as a good fat mystery story, or is it?

I'm pretty intrigued by solving the "mystery" through science and evidence, or at least demonstrating that the evidence supporting energy balance as the primary influence on fat gain and loss is very robust.  So much so that people can have confidence that embracing a calorie deficit will certainly result in fat loss.  The only way to return to fat gain after fat loss is returning to eating too much again.  Eating too much.  Now that's a tough habit to break.  Difficult to recognize in ones self, and difficult to overcome, but metabolic mystery isn't part of that.

Fat loss studies

Study: eating too much is cause of fat gain, not metabolism

What I found most interesting about this study is that it looked specifically at people who claimed to be resistant to fat loss, despite consuming a low calorie diet.  This group was compared to people with no history of "diet resistance", or failure to lose fat despite changing diet to lose fat.

There were no significant differences in metabolism between groups.  The group that perceived they couldn't lose weight were found to underreport food intake by about 47%, and overreport exercise by about 50%.

The data showed that the reason the obese subjects in this study had gained fat and weren't losing it was because of "an energy intake substantially higher than reported and an overestimation of physical activity, not to an abnormality in thermogenesis."  They ate too much and metabolism had nothing to do with it.  They perceived they couldn't lose weight because for whatever reason, they falsely accounted for their food intake and energy output.

This can help explain why people can feel so distraught when trying to lose fat, but failing.  If you strongly believe that you're doing everything right but in reality are experiencing a self deception of how much you eat and exercise, it's understandable that it can seem like nothing is working.

How does a person not realize they are eating 47% more than they actually are, and exercising 50% less?  We could say that knowledge of nutrition can be confusing, and sure, that is definitely out there.  Does that mean a person won't understand that poutine is more calorie dense than a spinach salad with light dressing?

Does that mean a person somehow mistakes 15 minutes of physical activity for 30 minutes?  How do you do that, consistently, day after day?  These are important questions to answer.  Fortunately this has been investigated, and is understood.

Study: Unexplained weight regulation turns out to be eating too much

In this study, "underreporting of energy intake from foods is a frequent finding with patients with disturbances in body weight regulation."  Here we find consistency in people who are feeling like they have unexplained weight gain, but really they were eating too much and convincing themselves they weren't eating too much.

 Underreporting food intake investigated, causes found

In this study it was found that underreporters can sometimes feel influenced to underreport foods that are less socially acceptable in terms of weight management, like sweets and fried foods.  People also made mistakes in estimating portion sizes, and felt inconvenienced by having to record food intake.

There is indeed something to folks who express certainty about not being able to lose fat despite trying. Research shows underestimating and underreporting how much they eat, and overestimating their physical activity is a common finding.

Is it possible that these studies just so happened to capture people who underreport their food intake, and missed people who actually do have "diet resistance"?  Maybe, but because that is a maybe and not a confirmed fact, doesn't mean we should jump to conclusions and claim the obesity epidemic is caused mostly by unexplained metabolic disturbances.  Especially when there is no scientific consensus of unexplained fat gain actually occurring.  It's important to realize that there is a strong tendency to ignore the facts and invent contrived reasons for fat gain.

We like to fool ourselves into believing that we don't eat too much, and we're not always willing or immediately able to be cognizant of this.  When we're fearful of recognizing we eat too much, we run away from the truth and rush towards non-evidace based claims of metabolism mysteries.  Pondering a metabolism mystery enables the habit of eating too much, and eating too much is rewarding.

The trouble with trying to support the idea that the obesity epidemic isn't due to overeating, is you have be able to demonstrate that most people who gain fat don't overeat.  You would have to show that despite serving sizes increasing, despite 1000+ calorie restaurant meals being very, very popular, and despite overeating in fact being very common, that, almost nobody overeats.

You would also have to show a consistent failure of a calorie deficit not producing a fat loss result.

Let's look at that.

Low calorie diets cause fat loss

It's important to know that in this study, as is generally the case in fat loss studies, all the study subjects lost fat successfully when on a calorie deficit diet.

No study subjects failed to lose fat.  This is where to get inspiration from.  No failures.  100% success. Calorie deficit caused fat loss in everyone.

Here's an interesting finding, which is not unique to this study, but well understood..

After losing about 6kg of fat mass, by following a calorie deficit diet, the subjects resting metabolic rate reduced by about 200 kcal/ day.

This is an important thing to realize.  Many people are mislead into believing that heavy people have lower resting metabolism, commonly referred to as a slow metabolism.  And that conversely lighter people have a higher resting metabolism. There are also many who claim to have special diets and exercise programs that "rev up your metabolism".

In fact people who lose at lot of body fat show a reduced total amount of calories needed for the day (24 hour averaged metabolic rate), and also lower calories per hour burned for the same exercise intensity.  Why?  It's physics.  When you weigh less it takes less energy to move you.  The great thing about facts is that they are immune to opinion, though many will try to supplant fact with opinion.

Don't be lead astray by this tactic.

As you lose fat your hourly metabolic rate will "slow," and that's not a bad thing, it's a natural thing.  The equation for calories in calories out stays the same.  After losing significant fat, a person will require less food over a day to maintain their new weight, or to continue losing fat.  To clarify, the physical and chemical act of fat, carbohydrate, and protein are used for energy doesn't really change.  That function of metabolism is fairly constant.  What changes is the total amount work our cells have to do.  More muscle cells doing more work requires more energy, fewer muscle cells doing less work requires less energy.  One 100W light bulb uses 100 Watts.  If you have 10 of these, each bulb still uses energy at the same 100W rate, but the more you turn on, the more total energy you need.  Turning on or off any single bulb does not cause the other bulbs to become 50W or 150W bulbs.

When our metabolism is so-called slower it isn't because individual cell function has slowed, it's because the total work all cells in the body combined is less.  When we have extra fat, simply breathing takes more energy because there is more resistance against our lungs expanding.  It's harder to pump blood through blood vessels that are compressed by surrounding fat tissue, and by atherosclerosis.  Carrying extra body fat makes for more work, so measured as energy needs per unit of time, say calories per hour, we tend to interpret more calories per hour as a faster metabolism. 

So not only do we have misinformation and urban myths on what metabolism is, and how it speeds up or slows down, the actual understanding of what metabolic rate refers to is skewed, leading to all sorts of contrived ideas about fat loss and fat gain.

In reality, it takes more energy to move more mass, so the heavier we are, the more calories we burn.  The lighter we are, the fewer calories we burn. This means 100% of claims for metabolism boosting strategies are bogus.  Nothing more than an attempt to appeal to the desperation of many to control their body fat.  You're not looking for a strategy to increase your metabolism, that is nonsense pseudoscience made to appear like something legit.

Of course the rate we use energy changes with exercise (because we have more muscle cells doing more work), but this will have no effect on body fat if we eat too much.  That's why we can have very active people who exercise a lot, yet still gain or maintain body fat, like defensive position football players.  That's why your friend who's into recreational endurance sports like cycling and running can maintain being moderately overweight for years, despite all the exercise they do, perhaps even putting on a few pounds.

If you're 20 lbs overweight and do half marathons or cycling centuries or whatever, but can't seem to lose that 10-30 lbs you want to, it's because you eat too much.

The real problem with all this?  We don't like to face the uncomfortable truth of eating too much.  It can cause us to want to retaliate, to feel bad, even angry.  Especially since overeating can be part of an escape from hurting, or can be a part of socializing, or just habit.

To lose fat you need a calorie deficit.  But also a determination to change how you think and feel about food, and about yourself.  Combine eating less with a gradual increase in exercise and your body uses fat stores to make up the energy deficit.

A bit of a side note, but significant side note.  We don't actually eat calories.  Although I've spoken previously about how we're really eating atoms of carbon, hydrogen, oxygen, and nitrogen, and exhaling carbon dioxide water vapour and peeing out nitrogen and water (thus accounting for the atoms we ingest and all the atoms we expel), all that carbon talk isn't that easy to digest.

We're so familiar with the term calories, that any other reference can seem confounding.  I assure you though, we are not eating units of heat energy, which is what calorie refers to.  The term calorie is used because it's an easier way to quantify the energy potential in the food we eat, and a relatively easy way to quantify energy used by cells. We're eating atoms, which make up molecules, which is what the food on our plate is , and what our stored fat is made out of.  But it's easier to conceptualize our total "energy" needs compared to our total molecule needs, though they represent the same practical outcome. We don't eat an actual calorie, we eat food that has potential to be used as energy, which we can measure in calories.  Cold pizza with a 1000 calorie energy potential is not hot, it's cold.  We are not eating heat energy, we are eating molecules of food, that when used as energy, produces heat as by-product, we measure that heat in calories.

The reason I mention this is because it's important to realize that fat isn't a mystery, and neither are calories.  We know exactly how many atoms of carbon, hydrogen, and oxygen are in a molecule of fat, we know how we break that down, and we know how to measure the carbon dioxide and water we exhale.

We understand fat gain and fat loss right down to the atom, and have physically measured the total carbon we consume and release.  In everyday vernacular we refer to this as calories in - out.  There is no mystery about fat gain or loss, so the current fad of claiming that fat gain is not understood is very worrisome because it can give people the impression body fat is beyond our control and we're destined to suffer poor health effects of fat gain.  This isn't true, studies prove over and over that eating too much causes fat gain, and that this fat gain is reversible with eating less food than we need for the day, or, more commonly, a calorie deficit.

Back to the study.  This study was looking at differences in fat and carbohydrate amounts in a calorie reduced diet.  Since everyone lost nearly identical amounts of body fat, the carb and fat intake, in my opinion, seems unimportant.  The study authors don't agree, and felt that the marginal differences were important.  Regardless, everyone lost fat by eating less.

Calorie deficit leading to fat loss can reduce dosage requirements of blood pressure meds

In this study 100 people were followed over about one year. Study subjects were placed on an approximate 1000 calorie deficit (daily) to decrease body fat.  People received help with behavior modification, and planning for using both strength training and cardio training.

All subjects lost body fat while on the calorie deficit diet.  Be inspired by this.  Everyone was successful at losing fat.  No special diet, no pills, no hyped claims of fat burning exercise.

Does eating fish cause extra fat loss when on a calorie deficit diet?

In this study of 118 people, some ate fish two times per week and others with the same calorie deficit but no fish.  All those who sustained a calorie deficit lost about the same amount of fat, fish or no fish.

This doesn't mean fish consumption isn't an important consideration in a healthy diet, it just means it doesn't make any difference in fat loss.  Just calories in, calories out.

More fact inspired inspiration!  Everyone lost fat.

Can a larger breakfast, but same total calories over the day produce more fat loss?

This study showed that when a 600 calorie per day deficit was weighted with 70% of calories consumed at breakfast compared to 55% consumed at breakfast, that more fat was lost with the larger breakfast.

The first take-home is that everyone lost fat on a calorie deficit.

It's studies like this one, that don't investigate exactly why the weight loss difference occurred,  have studied authors filling in the gaps in their research with suppositions that suggesting obesity is caused by something other than eating too much. Of course, there is zero evidence for these conclusions, but nonetheless this is where many tend to go.

We know that a larger meal can be more satiating than a smaller meal.  Could it be that eating a larger breakfast increases the ability for people to avoid snacking and increased serving sizes later in the day?

A Mayo Clinic article suggests just this.  Also, skipping breakfast or having a small breakfast provides less energy, which is associated with decreased physical activity.

When critical thinking is applied, and we look at the physiology we know, we can find that there are reasonable causes to investigate, other than speculation about some magical unexplained quirk of metabolism.

Ok, but what about eating a huge breakfast, big lunch, and big dinner?  That's pretty popular too.  So increasing the total calories at breakfast doesn't guarantee that you'll be less tempted to eat more later on in the day.

Looking at a larger breakfast as no-brainer quick fix isn't likely to result in overall behavior changes and the important changes in how we think and feel about food and our health.

Each of these studies demonstrate that all subjects who consumed a calorie deficit diet, (ate fewer molecules of food than were needed for the day), lost fat. And yes, we know exactly where the fat goes! You exhale carbon dioxide (mainly).  In my opinion, it's important that we move beyond the ostentatious headlines and click-bate that leads us to articles that tell us what we want hear; which is usually something that allows us to justify overeating, or our idea that we are different and calorie deficit doesn't effect us.  Right now we only have evidence that shows the single cause of fat gain is eating too much, but there are many things that cause us to feel compelled to eat, and that we can deceive ourselves into believing we don't eat too much, because that enables us to justify the rewarding behavior of overeating.

With so much suffering caused by excess fat gain and obesity, including medical conditions and emotional turmoil, it's important to be able to provide the right support, and realistic hope of success with evidence based reasoning.

Research shows overeating does cause fat gain.  There isn't any confirmed evidence that something else causes fat gain. If someone try's to claim otherwise, remember that such an outstanding claim requires outstanding evidence.  Don't accept patchwork claims that can't produce prodigious evidence of accounting for the mass.  We know how to measure the mass of molecules of food we eat and how to measure where those molecules go.  If someone claims fat gain without overeating, or that calorie deficit doesn't cause fat loss, they would have to be able to demonstrate this in a large study where a large number of people didn't lose fat on a measured and confirmed calorie deficit (not estimated). The researchers would also have to bear the burden of proof, showing where the molecules did or did not go. Don't hold your breath waiting for this because it isn't going to happen.  There is no evidence to even suggest that our understanding of physics is so wrong that we don't know how to measure mass.

The claim of fat gain without overeating is just another popular fad amongst a history of gimmicks and pseudoscience nutrition claims.

Research confirms that a calorie deficit is 100% successful at causing fat loss.  If a person isn't losing fat despite trying, research confirms they will be deceiving themselves about how much they eat and exercise.  This is human nature.  It's part of our human fallibility to avoid dealing with uncomfortable truths by creating diversions.

And that's fine.  It's ok to step back and accept our natural fallibility, then move forward by changing our habits.

Overeating is part of our culture, and so many of us are suffering the ill-effects of this.  Stopping overeating is what will stop the obesity epidemic.   We are deeply emotionally invested in defending eating too much.  Eating too much feels important to us.  It feels like it's needed.  Moving away from overeating feels unrewarding, feels uneasy, feels burdensome.  Eating too much feels good at the moment, and a lot of the time we're eating too much we do so in the company of friends and family, and so we contrive the conclusion that eating to much is a necessity for good times.

It's a repeated association we naturalize and don't challenge.  I ate a lot of food, I had a good time, therefore, more food equals more good, and consequently by extension, less food equals less enjoyment.  These are logical fallacies.  Where logic and reason are attenuated by a habituated emotional response to a dopamine producing reward (overeating).

We're naturally defensive about the connection we have to friends and family.  The strength of this natural defence can also easily override logic and reason.  We can feel emboldened to conflate the value of our family and friends with the perceived value of eating too much.  The result is we can feel that a suggestion to eat less equates to suggesting we will therefore devalue our enjoyment of social occasions.

And so we're conflicted.  We cherish eating too much but it's hurting us.  We don't want to acknowledge that hurt we're causing so we deceive ourselves into believing we're not eating too much or that eating too much is ok.

We rationalize that stopping eating too much equates to stopping enjoying eating, and stopping enjoying time with friends. We invoke the "you have to live a little" excuse to justify overeating, and it seems legitimate because of the enjoyment we experience when eating too much.  But it's all rationalization and self deception.  What we ignore is that of course the value of our friendships and enjoyment don't actually come from only eating too much.  It isn't as though someones story of how their day went has no value without eating too much.  It isn't as though a warm embrace is devalued by eating healthy.  It isn't the case that we won't laugh at a funny moment because we failed to eat twice as much food as we need.  We also ignore the fact that the "wow this tastes great" feeling we experience is actually abnormal excitement of our brains reward centre.  Sure, extra salty, fatty, sugary food tastes really good, but it actually tastes better than whole foods can taste and so we become used to this expression of reward intensity and are not satisfied with less.

We don't want to acknowledge this.  We want to keep that reward coming.

At the same time we're aware that too much fat gain is bad for our health so we want to lose it, but we don't want to stop the overeating that causes it because that can feel emotionally difficult, and it includes breaking the compulsive bond to rewarding ourselves through overeating.

When we move beyond the rhetoric, false claims, and enticing promises of false hope, we're less likely to become trapped in misguided beliefs that thwart our attempts at improving our health.

We have to get passed this self inflicted society wide curse of placing eating too much on a pedestal. We have to recognize our self deceptions where we rationalize eating too much, or we eat too much but justify it as normal and necessary for happiness.

We can do all the things we like doing without eating too much, and all those things will be enjoyable, if not more so.  And overall, life will be less stressful and more healthy because we won't be harming ourselves through chronic overeating.

Exhale to lose fat

Where does fat "go" when we burn it off?

Nearly all the stored fat we use as energy is expelled primarily through our lungs when we exhale carbon dioxide and water vapour (fat is made of carbon, hydrogen, and oxygen).

All of the food you eat can be accounted for by measuring everything that goes in and out of our bodies.  There are no mystery calories, and there is no mystery fat gain or fat loss.

If we eat too much, the extra food is stored as fat.  If we eat less food than the total energy we burn off in a day, we use energy from our fat stores.  We can measure the process of using food for energy in the carbon dioxide we exhale.

This is a normal measurement and is done daily in exercise labs all around the world.  I've been looking at this data for decades as a coach, and have had the testing done on myself many times. There's a description of this test at the bottom of the article (with photos).

It's all about accounting for mass.  We know the mass of molecules of carbs, fats, and proteins, and we know how we use the components of those molecules for energy, and we know how much energy is needed to move the mass of our bodies and keep our cells functioning.

It's an energy equation where we are able to accurately account for the mass of what we eat, and the by products of metabolism.  It's physics. Don't be misled by corny non-evidence based ideas that don't account for the mass of molecules.

I realize all this molecule stuff doesn't sound as promising or as exciting as the latest "fat loss breakthrough" claims, but it is reality.  All the fad fat loss claims out there are always proven to be fake anyway, so let's bypass the hype and go straight to the science.

Learn this reality so you can't be fooled by weight loss gimmicks. And more importantly, if you're trying to lose fat and are feeling frustrated about the process, learn how your body works (for real), so you can lose fat while by-passing the phoney promises, the hype, and all the crooks carefully constructing great sounding lies. We know fake news travels faster and reaches more people than supportable facts. Give the facts a chance.

Via a fairly complex chemical pathway, we breakdown fat molecules to make energy, and have some waste products left over, namely water and carbon.

The fat molecule: a triglyceride (right) is made up of atoms of carbon (black), hydrogen (grey), and oxygen (red).  Lot's of these are stuffed into fat cells in our "love handles", and aroud the rest of the body.

Carbon dioxide molecule (1 carbon + 2 oxygen).  We breathe out a bunch of these.  The black thing in the middle (carbon) used to be part of the fat molecule above.  After we break apart the fat (break the carbon-hydrogen bonds) for energy, there is carbon, hydrogen, and oxygen left over, the same amount as we started with, but no longer put together as a fat molecule. At the end of the energy production cycle, oxygen bonds with hydrogen to make water, and oxygen bonds with carbon to make CO2. We exhale the CO2.

Water and carbon mass, formerly fat in fat cells, former (too much) food on a plate, leaves our bodies through three primary paths.

Exhaling

The toilet

Sweat

A very tiny amount of the water is lost in sweat and through the bowel, some is recycled, and a fair amount is also exhaled as water vapour. The vast majority of the mass lost in fat loss goes out, a little bit at a time, in the carbon dioxide we exhale, save for the less than 1% that goes into urine.

Fat doesn't "melt" off, is not converted to muscle, can't be spot reduced with abdominal exercises (or triceps exercises or whatever), and isn't increased or decreased due to different genetics.

You also won't lose fat by exercising in a "fat burning zone", unless you have a calorie deficit, in which case it doesn't matter if you burn fat during exercise or not.  Only a calorie deficit, considering all calories consumed VS expended, will result in fat loss.  Consider this.  If you burn off 500 calories exercising in a fat burning zone, but the total calories you eat is the same as the total calories you expend during the day, no fat loss will occur because you have replaced everything you burned off.

The reasons why this is, are explained here.

We eat food, which has molecules of fat, carbs, and protein, which are made of mostly - you guessed it - carbon, hydrogen, and oxygen atoms.  When we eat too much we store the extra as fat (carbon, hydrogen, and oxygen atoms).   When we don't use the food molecules we eat as energy, we're literally left holding the bag.  We have left over molecules of food with nowhere to go, except our fat cells.  That's where we put the overflow.

We don't have anywhere else to put the fat.  We can't store it in our heads, though some might argue that some are capable of this feat. There's no room in our bones for lot's of excess fat from chronic overeating.  Our blood lipids can increase, but this is really a temporary thing as it takes time to shuttle excess fat to our fat cells.  Our blood can't handle all the extra food we overeat - it would simply become too dense and would't be able to be circulated.  We have adipocytes (fat cells) in our organs and do store some extra fat there, which is really bad for our health, but the storage capacity in our organs fat cells is very limited compared to the virtually unlimited capacity of our fat cells in our large adipose sites between our muscles and skin.  If we fill up our existing fat cells and keep over eating, our bodies just make more fat cells.

We don't poop it out - if we did we would have very oily stool every time we overate fat.  Sorry for the detail, just eliminating some of the common guesses out there.  When we do the drill down, all extra food we eat can be accounted for in the storage of fat in our fat cells.  It simply isn't biologically possible to put it anywhere else.  If it were, we'd see obvious evidence of this.

When we use up the stored fat, that mass has to go somewhere, it can't just disappear into nothing, that's not realistic.

Are you breathing?  Some of what you are exhaling used to be excess fat. Some of that carbon comes from using carbohydrates and protein as a fuel as well, so not all the carbon we exhale comes exclusively from fat.  If you have a calorie deficit, the molecules of fat used to make up for what you didn't eat come from your fat stores and are lost through exhaling carbon dioxide.

Without a caloric deficit or surplus, what you exhale matches what you ate. There is no net gain or loss of fat mass.

Visualize your foods in their microscopic form; a bunch of molecules. Follow the journey of these molecules through your digestive tract and into your body.  The molecules will be used for energy by every cell in your body.  If you ate more molecules than your cells need for energy that day, the unused molecules are shuttled to your fat cells.

Your living cells use energy 24/7 even if you don't eat enough for the day.  Your cells still use molecules of carbohydrate and fat for energy, but when what you eat isn't enough to supply energy needs for the day, your body uses fat stores, and every gram of fat used can be accounted for.  You exhale it as carbon dioxide and some water vapour.

Actually, fat is continually shuttled in and out of our fat cells. Kind of like a storage depot that receives and ships out product every day. When our energy consumption matches our energy use, fat cells have no extra fat stored or lost.  Like a storage depot receiving 10 boxes but also shipping out 10 boxes.  Eat too much, and more fat is stored than used (you receive 10 boxes but your customers only need 6 boxes from you), leaving you with extra inventory.  Have a calorie deficit, and more fat leaves the fat cells than is put in, and you lose weight, a few grams at a time.  You're always breathing, and when you have a calorie deficit, some of the CO2 you're exhaling comes from fat in your fat cells, even when you're sleeping.  You're still burning molecules of sugar, fat, and protein to make energy (measured in calories) when you sleep.

Through being a little more active and eating a little less anyone can create a calorie deficit, and reduce their extra fat inventory.  A calorie deficit can't fail at producing fat loss, but we can fail to accurately account for how much we eat and exercise, obscuring the truth of us eating too much.

In case you were curious about how much carbon dioxide mass we exhale- (and I know you are), here are the stats:

About 2.45 grams (0.005 lb) per hour at rest

Between 50 and 90 grams (0.11 - 0.2 lb) per day for the average sedentary person

350 - 400 grams for a moderately active person 

600 or 700 grams per day for a very active person exercising 1 - 2 hours per day.

In an hour of moderate to hard exercise the average exerciser will exhale about 350 grams of carbon dioxide (0.8 pounds).

A very active person will blow out about 700 grams of CO2 on the days they exercise for about 90 minutes.  That's nearly 2 pounds!  This accounts for the equivalent mass of food energy consumed for the day, if there is no weight loss or gain.  Despite nearly 2 pounds of CO2 being exhaled, if you eat more than you burn off, the extra goes to fat cells.  Ever gone for a run or going to the gym and justifying eating more because you worked out?  Sure, you burned off energy, but if you eat more than you burn off, fat gain occurs.  The gains can be accounted for, as can the losses if you burned off more than you ate.

You don't have to exercise 90 minutes a day to lose fat, I only used that example because it exaggerates the values making it easier to see the difference.  150 minutes of moderate exercise per week and being mindful of reducing food intake is enough.

This exhaling carbon thing has been butchered and abused by diet "gurus" who invent crazy diets that involve, yes, "special" breathing techniques to breathe your fat away.  Impossible, of course, but because we can become desperate to lose fat, we can become susceptible to believing these false claims.  When you look at the calories recommended in these corny methods, they all use a low calorie diet.  They don't address this fact, and use misdirections to convince you "special" foods or food combinations have a magic influence on fat loss.  It's eating less, not the "special" claims, that is causing fat loss. The crackpots who push this stuff are gladly being paid by their customers whom they are lying to.

Changing how you breathe has no effect on fat loss.  You have to eat fewer calories (food energy) than you burn off in order for some of the carbon you exhale to result in fat loss.

If we eat as much carbon (from food) as we exhale, our weight will stay the same, no matter how much we breathe or how we breathe.

If we consume less carbon (from food; this is all about eating food, and what happens to it) than we exhale, we lose weight. For many people, weight loss is difficult.  People make different claims or assumptions about why this is.  When investigated it's always found that people who make such claims or believe in common weight loss fallacies, don't realize they over-report their exercise, and under-report their food consumption.   This is easy to do in our overeating culture, and also easy to do when food is habitually used as a reward.  You're less likely to want to acknowledge overeating, because that would mean having to deal with eating less, which can feel like getting less reward.

Calories in, calories out.  All accountable by adding up the carbon.  Sure, it's complicated science to do the measuring to figure all this out, but that's what scientists do.  For us, the science is already done, and to benefit from the research, we need to eat less and move more, to achieve a calorie deficit.

While calories in, calories out is the sole equation for fat gain and loss, we also have to be mindful of meeting our energy needs without eating too little or exercising too much in desperation to lose fat. We need a certain amount of food to supply important nutrients, and to meet our healthy minimum energy needs.

Did you know that gas powered cars also use energy stored in hydrocarbons?  That's what we're blowing up in the cylinders of our automobile engines; hydrocarbons are in the molecules of gasoline.

Let's say you have 65kg (29.5lb) of gas in your tank when full.  Fill your tank, and your car weighs 65kg more.   Use half a tank, and you lose 32.5kg of mass.  As you burn gas driving, the gas level in the tank goes down, and the car weighs less.  Where does the mass go?  Out the tail pipe in the form of exhaust.  Every kilogram of fuel that goes into your engine can be accounted for in the exhaust.

Lets say you plan on a long road trip, taking a route where there aren't any gas stations for part of the trip.  You'll need to fill some gas containers and keep them in the trunk. Kind of like eating too much food and storing extra fat.  When the gas tank is near empty, you start using your stored gas, and now you have less gas in the trunk, and your car weighs less.  This is analogous to fat loss in people.

What if you had those extra gas containers in the trunk, but then came across a new gas station where you expected none to be?  Might as well take advantage and top up the tank right?  This might be like someone surprising you with a box of donuts (or whatever unplanned eating).  You "take advantage" and add to your fuel stores when you do that.  If you don't have extra energy expenditure to burn off the extra, you retain the excess in fat stores.  If you don't drive off the extra stored gas, It doesn't go anywhere.

Most of us manage our gas use in cars reasonably well, rarely running out of gas.  We pay attention to the gas gauge and have a fair idea of how much driving we get out of a tank (or range from a charge). Pretty much all of us drive our cars in this way.  We're already good at managing the daily energy needs of our cars. If we incorporated this skill into how we eat and exercise, seeing food as energy supply, it makes it easier to understand our food intake/ energy needs.  But we can still be find it frustrating to overcome the temptation to overeat.

To lose fat we have to fill up less when we eat so we can use the extra energy we already have stored in our "tank".  We still need to replenish our supply of carbohydrates, proteins, essential fats, and vitamins and minerals daily, so cutting back too much deprives us of essential nutrients we need every day.  Remember the storage depot analogy, it's a continuous cycle.  If we cut off too much of the supply to the storage depot, the depot can't perform it's function because it won't be able to supply its daily baseline customer demands.  If we eat too little we can get tired and sick.

The only way to deplete the stored fat is to eat less than we burn off.

On average an approximate 500 calorie per day deficit is safe and reasonably manageable for most people, especially with adding a little bit of physical activity.

Gas mass in, exhaust mass out.  Storage depot boxes of product in and out.  A couple of analogies that very closely reflect our calories in - out balancing needs.

Carbon-hydrogen bonds, calories, food.  Just different words to describe the same thing in greater or lesser technical detail. Calories refer to the energy potential of food.

A lot of the mass of food we eat is not extracted into our bodies through our digestive system.  Much of it remains as the bulk that we - leave in the toilet.  A lot of the food mass we eat is actually water, so a pound of food doesn't have a pound of carbon in it. For instance, a 70 calorie, 28 gram slice of bread has about 2 grams of fiber and about 11 grams of water. About 40% of a slice of bread has no calories in it, and most of that portion has no carbon in it (the water).

Of the 70ish calories in that slice of bread (mostly from sugars, a tiny bit of fat, and small amount of protein), about 15% of the energy is used for digestion. We're left with about 60 calories worth of energy stored mostly in the carbon-hydrogen bonds of the sugars, fats, and proteins.

Fats, carbs, and protein are each different combinations of carbon, hydrogen, oxygen, and in the case of proteins; nitrogen as well. Fat is the most densely packed.

Like a shrewd accountant, your body can reconcile every molecule of food you eat with every molecule you use for energy and store as fat.  There is no metabolism mystery that causes unexplained fat gain, no genetic trait that causes people to gain fat without over eating, no verified accounts of people having a calorie deficit and gaining fat (impossible), and no verified accounts of people having a calorie deficit and not losing fat (also impossible).

The reason I wrote about fat loss from this perspective was to show that fat has a known value.  There is no mystery as to what fat is, and where body fat comes from and where it goes.  My hope is that I can put a small dent in all the contrived, misleading, misunderstood, and urban myth idea's that are so popular.

I'm not suggesting we focus conceptually carbon atoms to control body fat. That's impractical.

In day to day practical application we’re thinking about portion sizes, number of servings, and matching that up with our activity level.  We also need to be mindful of how some foods that fire up our reward centres can cause us to feel really compelled to eat too much.  Noting the difference between feeling hungry because you need the energy and feeling a craving because you want the reward of a favoured food is important.

Healthy fat loss is about burning off more than we eat and to do so we need to be mindful of how many calories (food energy) we're consuming.  What I offer here is proof of the fact that we know what a "fat roll" is made out of, where it comes from, and where it goes.  Creating a caloric deficit works to lose fat, and it works because it can't not work; it works because of physics and chemistry that is real and measurable.

No tricks, no gimmicks, no mystery.  We know how this works. Fat loss is explainable. Don't let anyone fool you with weird ideas, alternative facts, or fake news.  Be wary; the gimmick pushers are practiced at seeming sincere, know about peoples vulnerability, and know how easy it can be to manipulate a person feeling frustrated and desperate.  They make themselves appear as though they are empathetic and are on your side.  They know how appealing this can seem.  But really they are scammers.

Eat less, move more, and address where your eating motivation comes from.

Mayo Clinic says what I just said here, but they do it in two paragraphs click here

What are you eating?  Use eatracker to find out, and Cronometer

Update! Apparently I made a scientific breakthrough without knowing it... - sort of.

A recent study in the British Medical Journal has published a study on this topic, but interestingly, they state that this is a novel perspective on how fat loss works.

Not really, since I posted this article a year before the study was published., - and also... yeah... um... -everything I've written here is standard, basic science- that has been known for several decades.

Study: When somebody loses weight, where does the fat go? 

So how do we figure out how much carbon dioxide (CO2) a person is exhaling?

Why, in an exercise lab, of course..

Below is a picture of me in the University of Manitoba's exercise lab having my VO2 max assessed.

The tube in my mouth delivers the gases I breathe in and captures the gasses I breathe out.

In the print out below there is a VCO2 column that shows how much carbon dioxide I was exhaling in liters per minute.  At my moderate pace I was exhaling about 330 grams of CO2 per hour, some of the carbon in the CO2 from fat, a lot from carbs, and a little bit from protein.

For you calculating types out there, the density of CO2 is 0.001977 g/mL

This carbon thing isn't my idea, it's proven through research, and we've been measuring this for many decades. It's no secret.

The most challenging part of successful weight loss isn't the mechanics of eating less; it's changing our habits, our thoughts, and our sense of reward with food and exercise.  Studies show that the single reason why many people regain fat after losing it- is because they stop the new healthy habits and return to previous overeating habits.  The return is made because, as many will be able to concede, it's very difficult to get past the strong internal drive to overeat.  I have a lot of posts on how to do this though, so read my blog articles and learn how to lose weight and get fit.

Calorie denial... why we can't face the truth of overeating. Click here for article