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Which would make me fatter 10lb of fat, or 10lb of celery.
July 30, 2009 10:57 AM   Subscribe

If I ate 1lb of fat each day for a week would I gain more weight than if I'd eaten 1lb of celery each day for a week, and if so why.
posted by zeoslap to Health & Fitness (47 answers total) 6 users marked this as a favorite
 
http://www41.wolframalpha.com/input/?i=calories+in+1+pound+of+celery

http://www41.wolframalpha.com/input/?i=calories+in+1+pound+of+chicken+fat

pretty much sums it up
posted by bobot at 11:00 AM on July 30, 2009 [2 favorites]


Well, celery is mostly water and fiber, so chances are you'd piss and shit away a lot of those pounds of celery.
posted by dersins at 11:00 AM on July 30, 2009 [1 favorite]


Fat is approximately 9 kilocalories per gram. Celery, on the other hand, is mostly composed of indigestible cellulose, and thus, much closer to 0 kilocalories per gram.
posted by NucleophilicAttack at 11:00 AM on July 30, 2009


Think about drinking 1lb of water a day, and how that would affect your weight.
posted by smackfu at 11:01 AM on July 30, 2009 [2 favorites]


Yes. Your body would absorb and retain more material from anything that you could you classify as "fat" than it would from celery, which is composed mainly of water and fiber.
posted by contraption at 11:01 AM on July 30, 2009


Fat has more calories than celery. Weight gain is basically math based on the fact that 3500 calories = 1 lb of weight with a little bit of hand-waviness based on what your basic metabolism is.

- a pound of celery has basically 80 calories.
- a pound of fat (let's say butter) has 3250 calories
posted by jessamyn at 11:02 AM on July 30, 2009 [5 favorites]


Cellulose cannot be metabolized by humans. Celery is mostly water and cellulose. Therefore, unless you are a a panda or some kind of alien, most of the celery you eat will come out your backside. You might gain some weight due to water retention.

fat, on the other hand, will metabolize in humans, and quite well at that. The problem, however, is that your body can only convert food into fat so fast, so if you are eating a pound of fat per day, you may be eating too much too quickly for it all to be stored -- your body will excrete unprocessed/under-processed food to make way for incoming food.
posted by trcook at 11:14 AM on July 30, 2009


Your body would store the fat for use as an energy source in case of future famine. As an inhabitant of a developed country, of course, you're highly unlikely to ever experience a time of famine, but your metabolic processes don't "know" that, having been shaped by millions of years of evolution when famine was a distinct possibility, and not so much by the last few hundred years when it was not.

Assuming you're already properly hydrated, the water from the celery (or at least, a roughly equal volume of water to that contained in the celery) and the indigestible fiber would be excreted, and those two account for most of the weight of the celery.

Now, if you were dehydrated before you started, and didn't have any other source of food or water during that week, you would gain some weight from the celery as your body took the water from it and held on to it.
posted by DevilsAdvocate at 11:15 AM on July 30, 2009


Perhaps celery was a bad example due to the water content, but take sugar for example

1lb sugar = 1700 calories
1lb fat = 3300 calories

Am I just retaining more of the fat? Is a calorie really a measure of how well my body is at disposing of it? So water = 0cal, body gets rid of almost all of it, fat 3300cal, body clings to it, and sugar at 1700cal the body can get rid of it half as well as fat?
posted by zeoslap at 11:25 AM on July 30, 2009


No. Calories are just a measurement of the amount of chemical energy stored in food; specifically:

The kilogram calorie, large calorie, food calorie, Calorie (capital C) or just calorie (lowercase c) is the amount of energy required to raise the temperature of one kilogram of water by one degree Celsius.

Fat simply has more chemical energy stored in it than sugar (or other carbohydrates.)

There can be some variation based on how your body metabolizes fat, carbohydrates, or proteins that may affect how many calories are stored/consumed, but in general there is a direct link between the number of calories consumed and calories used/store.
posted by theclaw at 11:37 AM on July 30, 2009


I think you're thinking that because a food has a higher fat content, you somehow are going to hold onto more fat. That isn't entirely true.

Like theclaw says, it's a measure of calories. Both the 1 lb of sugar and 1 lb of fat are going to get broken down to energy in your body - 1750 and 3300 that you mention.

Then, your body is going to use calories for it's daily needs. At the end of the day, since there are more calories from the fat, your body is going to have to store those excess calories, and it will become fat on your belly.

fat you ingest doesn't directly become fat on your belly there a lot of steps in between.

This is also why it's important to be aware of those "non-fat" labels. Oftentimes, they'll have a higher calorie content then their "normal" counter-parts because they use excess sugar to make the food taste good.
posted by unexpected at 11:42 AM on July 30, 2009


It sounds like you need to understand a little more about how calories and energy are used and stored by your body.

A calorie is simply the amount of energy required to raise the temperature or 1 gram of water by 1 degree Celsius. Thus, it's a measure of how much energy is in a substance. Food calories are actually kiloCalories (colloquially known as Calories with a big C).

When you eat something, your body breaks the chemical bonds in your food, and then uses that energy to do all sorts of useful stuff: keeping your heart pumping or muscles running, providing ATP for chemical processes, releasing heat to keep you warm, etc.

The molecules comprising your food can be broken down into just a few different types of molecules. Carbohydrates have simple sugars as their basic building blocks and include complex structures like starches. Proteins are built from amino acids and Nucleic acids are built up from nucleotides. Then there are fats, which are more accurately called lipids.

Being composed of different things, each of these molecule types have different amounts of energy stored in them. Lipds are, by far, the most energy rich, which is why sugars (fructose, sucrose, et al) have far fewer calories than fats (oils, butter, etc). In simple terms, there are just fewer high-energy bonds to break per gram of fat, than per gram of sugar.

Okay, so that's why different foods have different amounts of calories. Now, what about storing fat in our beer guts? Well, for most of our evolutionary history, food has not always been this abundant and cheap. As a result, when we're taking in loads of calories during a glut, our bodies are able to take some of that energy and store it away for lean times. The body does this primarily by adding fat. (remember, they're a very efficient and energy rich way to store energy). Later, if we're short on food, those fat reserves can be tapped, and metabolized so that our body doesn't shut down completely every time we get hungry.

You can think of the whole process as an equation:

   Calories eaten - Calories burned = net Energy gain.

If your net is positive, you'll begin storing energy (and gain weight). If it's negative, you'll begin to burn stored energy and thus, lose weight. This conversion to fat in the body happens at a rate of roughly 3500 Calories per pound of stored fat.

So, imagine you're currently eating 2000 Calories per day, and your weight is constant. If you start eating 250 less calories per day, you'll lose weight at the rate of about 1 pound every two weeks. Remember, there are two terms in that equation - energy in, and energy out. So, if you want to speed up the process, you could start exercising, and if you burn an extra 250 calories per day, you'll lose the weight twice as fast.

So yes, eating a pound of celery will result in far less weight gain than eating a pound of fat. It's not about the weight of the food, it's about the caloric content.
posted by chrisamiller at 11:52 AM on July 30, 2009 [8 favorites]


The Wikipedia article on human digestion is thorough, as always.

There are many different ways that food is broken down by different organs and transmitted across various membranes into our blood stream. Fat, Carbohydrates (sugar being one type), and Protein aren't just words made up by a nutritionist - they are different kinds of caloric energy storage molecules that are broken down from food and used in different ways.

So when you eat 1 lb of fat, that fat doesn't go directly to your stomach and thighs. In most cases, it is converted to fatty acids or tryglicerides which are stored and then used by various systems for energy. So no - 1 lb of pure animal fat will not be stored as 1 lb of pure human fat - lots will be burned now, some will be burned later, and some will be excreted. 1 lb of sugar does not follow the same digestive process and energy from carbohydrates is utilized differently than energy from fat or proteins. There is some cross-over, but there's also good reason why we're encouraged to eat a diet that's balanced in these three nutrients.
posted by muddgirl at 11:54 AM on July 30, 2009


That's kind of what I'm getting at - I can't quite visualize what exactly it is that the body is storing - i.e where the actual mass comes from, and what the body does with the extra 1/2lb of sugar mass.

food a = 1kg = 1000 calories.
food b = 1kg = 500 calories.

What is my body doing to get rid of the extra 500g of mass from food b- is it turning it into heat?

Because the way I see it, that mass is either turned into heat, or you flush it down the sewer.
posted by zeoslap at 12:00 PM on July 30, 2009


To piggy back on this question: Isn't the chemical energy measured by burning something a really poor approximation of the energy our bodies can use? Is it really supposed to be interpreted as an upper bound? Because I'm sure there are things that burn really well and can't be converted to energy by our digestive tracts - gasoline comes to mind.
posted by phrontist at 12:02 PM on July 30, 2009


is it turning it into heat?

Kind of. It's turning it into energy, which it uses to do stuff like cause your heart to contract, moving blood through your body, etc.
posted by dersins at 12:03 PM on July 30, 2009


On preview I think I get it.

"In simple terms, there are just fewer high-energy bonds to break per gram of fat, than per gram of sugar."

So it's easier for the body to burn the sugar - and hence get rid of the mass, than it is the fat. So the fat sticks around longer than the sugar, which means your weight goes up because the body can't burn it as quickly.
posted by zeoslap at 12:07 PM on July 30, 2009


Because the way I see it, that mass is either turned into heat, or you flush it down the sewer.

Yes.

Again, celery is the perfect example. It's almost entirely cellulose (indigestible, also known as fiber) and water. You excrete both of these things. The few molecules that aren't these substances (mostly sugars and such) are fed into your metabolism. If your body needs the energy, it's used by your body as a power source and turned into, say, mechanical motion, and ultimately heat.
posted by chrisamiller at 12:08 PM on July 30, 2009


zeoslap: The mass is either incorporated in to your body or is expelled via urination/defecation. No mass is turned in to heat, as this would require a nuclear reaction - absent fission/fusion, mass is conserved. The energy we get from food is from the chemical bonds between atoms, bonds being how we describe the way the tiniest constituent particles of matter with mass interact with one another. It turns out that energy is released by breaking atoms out of certain stable configurations (molecules) - and this energy is used by our bodies to do the things we do.
posted by phrontist at 12:08 PM on July 30, 2009


no, fat does not stick around longer. fat has more calories. if you don't use those calories, your body does not flush it down the sewer, it says "hey, save these for later!!" and stores them.
posted by unexpected at 12:09 PM on July 30, 2009


So it's easier for the body to burn the sugar - and hence get rid of the mass, than it is the fat.

I think you're too hung up on the mass thing. If you weighed all the food and water you ate, and then weighed all of your waste products, they'd be really quite close to the same mass. (Waste products include feces, urine, water lost through sweat, respiration, etc).

What we're talking about here is energy, which requires a little bit different way of thinking. Your body is much more concerned with how much work it can do with the food than how much the food weighs.
posted by chrisamiller at 12:12 PM on July 30, 2009


Ha! Sometimes it sure feels as though something is going nuclear down there :)

Okay, so if energy is the breaking of bonds why does fat - with fewer high energy bonds - produce more energy than sugars?
posted by zeoslap at 12:13 PM on July 30, 2009


ARGGGH - that was a massive typo on my part. The fats have MORE high energy bonds.
posted by chrisamiller at 12:15 PM on July 30, 2009


dreadfully sorry for clouding the whole issue with that typo
posted by chrisamiller at 12:16 PM on July 30, 2009


If zeoslap (or I) eat a pound of chocolate, the most weight that can be gained is a pound right?
posted by JohnnyGunn at 12:16 PM on July 30, 2009


Ah, then it all makes perfect sense now, thanks for being so patient guys :)
posted by zeoslap at 12:17 PM on July 30, 2009


Later, if we're short on food, those fat reserves can be tapped, and metabolized so that our body doesn't shut down completely every time we get hungry.

Fat is actually always used as an energy source. The level of intensity in activity largely determines what percentage of fat vs muscle glycogen is used. When walking, for example, more than half of our calories burned come from fat. Sprint, and it can be over 90% glycogen used.

Glycogen is a much more efficient fuel for muscles - so much so that the infamous 'wall' in a marathon is the almost total depletion of muscle glycogen. When you run out of it, you simply can't use fat stores to continue to run fast. But, basic body function can and does use fat to keep you alive. You can improve your ability to use fat as fuel, but it will never be a high-performance fuel.
posted by jimmythefish at 12:20 PM on July 30, 2009


If zeoslap (or I) eat a pound of chocolate, the most weight that can be gained is a pound right?

Not exactly. The weight doesn't matter, it's the caloric content.

Fat is actually always used as an energy source. The level of intensity in activity largely determines what percentage of fat vs muscle glycogen is used. When walking, for example, more than half of our calories burned come from fat. Sprint, and it can be over 90% glycogen used.

Exactly. People seem to miss the simple idea that aerobic means with oxygen. If you are exercising and become breathless you have entered into an anaerobic condition. That's simplified but correct for the most part.
posted by P.o.B. at 12:30 PM on July 30, 2009


If zeoslap (or I) eat a pound of chocolate, the most weight that can be gained is a pound right?

Yes, conservation of mass dictates this.
posted by merkuron at 12:40 PM on July 30, 2009


Try this: think about how different fuels burn. Some burn hotter than others, some slower. Some provide more energy, some less.

Burning a gallon of jet fuel will give you more heat and more energy than burning a gallon of regular gasoline. The regular gasoline has more energy pound-for-pound than coal. The coal has more energy pound-for-pound than wood.

Fat is like jet fuel. It's not "harder to burn" — it just releases more energy when you burn it. You get more miles per gallon, so to speak, on fat than you do on carbohydrates. That's good if your goal is to do a lot of work on a small volume of fuel. It's bad if your goal is to use up a large volume of fuel without doing much work.
posted by nebulawindphone at 12:55 PM on July 30, 2009


conservation of mass dictates this.

but "weight gain" involves water retention so all bets are off, mayhaps.
posted by @troy at 12:56 PM on July 30, 2009


some burn hotter than others, some slower cooler
posted by nebulawindphone at 12:58 PM on July 30, 2009


Not to mention that a pound isn't a measure of mass, but rather of force. The unit of measure of mass in English units is slugs.
posted by electroboy at 12:58 PM on July 30, 2009


If you ate a pound of chocolate it is possible to "gain" (fingerquotes) more than a pound if you had previously been on a ketogenic diet or had just completed a lot of exercise. In order to store energy in the form of glycogen in the muscles the body must use a lot of water, so the net increase in your body mass will be more than just the food input, i.e. you will retain more water. This is why people that just start a low or zero carb diet can lose crazy amounts of weight, because they are depleting their glycogen stores which causes a corresponding decrease in the amount of water the body has to retain. But since much of that loss is water it really represents a transient condition, and it will all return if they cease the ketogenic diet.
posted by Rhomboid at 12:58 PM on July 30, 2009


One thing that's useful is to understand what fat it is -- a collection of triglycerides, which can be a feedstock for . . . biodiesel!

The body can assemble blood sugars into triglycerides, stuff these fatty acids into fat cells for safe keeping, and later tap these triglycerides from fat cells when the body senses it needs more energy in the bloodstream.
posted by @troy at 1:00 PM on July 30, 2009


As an aside, this highlights why protein is such an excellent food - it gets metabolized to both carbohydrate and fat if there is already enough protein in your system to satisfy your requirements. Carbohydrate can be converted to fat. Fat will remain fat.
posted by jimmythefish at 1:06 PM on July 30, 2009


Not to mention that a pound isn't a measure of mass, but rather of force.

This is a really common mistake made by laypersons. Pound-mass is a measure of mass. Pound-force is a measure of force. On Earth at sea level they are conveniently equal. This isn't true on places like the Moon. It is entirely correct to speak of a pound as a unit of mass, as long as you keep your units straight.
posted by muddgirl at 1:11 PM on July 30, 2009 [2 favorites]


Mass (weight) does not equal energy.

Let's ignore the energy side of things for a moment, and concentrate on the mass. When you eat something, your body can do one of three things with the physical mass of it.

1) put it straight back out again. This is what you do with fibre (cellulose). Your body can't digest it as your stomach acids aren't strong enough in the time it spends in there, so what comes in, goes out the back. These things still serve a function; fibre is essential to keeping your digestive system moving, for example, so you can get rid of the toxic stuff too like dead blood cells (which is why poo is brown - otherwise, it'd be largely green or white)

2) borrow it temporarily. You do this with water; it comes in, you use it in your blood, sputum and sweat etc, then out it goes again in your breath, in your sweat, in the loo. This also applies with many trace nutrients.

These two cover a large amount of what you actually eat and drink in a day by mass; much of it is only in transit through you for a while.

3) You convert it to something else and use it directly or store it, then what's left over gets added to the waste stream.

Step 3 is where energy comes in. Some things have more energy than others.

Think of it like fuel; if you burn a log of wood, you get a certain amount of heat and light (forms of energy), and the waste (ash, cinders) is left over. Where did the mass go, as there's a lot less ash than log? Well, quite a bit of it combined with oxygen, and left as carbon dioxide.

You do the same; a lot of your waste is actually in your breath as carbon dioxide, a waste product from 'burning' it in your body. While you don't actually burn it to get heat, you do get the energy out in chemical reactions, and use that to do useful work, such as moving your muscles and heating your body (you're a warm blooded mammal remember). Some of that energy is also stored in chemical form in your body (fat) if you take in more than you spend.

So to return to my first line; mass does not equal energy.

In terms of mass, virtually all that comes in goes out; fibre in your poo, water in your piss and sweat and breath, carbon dioxide in your breath. A little bit is broken down and used to make muscles, repair bones, replace skin cells, fat cells, and that's what makes you, you.

In terms of energy, if you take in more than you use, your body will excrete some (sugar in your urine), and store the rest in fat cells.

So if you eat X mass of food in a day that's energy poor, such as celery, salad, lean meats, then you'll stay steady or lose weight, as your body has to burn fat in order to supply the energy you need to move around. If you move around a lot (exercise), then you need more energy, and again your body will tap your reserves as needed in order to supply that.

If instead you eat X mass of food in a day that's energy rich, such as sugar or fats or high fructose corn syrup, you'll still excrete about the same (though you will breath out more carbon dioxide from 'burning' more sugars) but some of that mass will go round your middle. But it's the energy in the food vs how much your spend that determines how much your body stores, not the mass it came in.

Let's assume you're a steady weight, and spending as much energy as you eat.

You now eat some extra food; what happens to it?

1 pound of lettuce has about 65 Calories in it (a tiny bit of sugar). Using the usual formula of 3500 calories excess = 1 pound weight gain, that pound of lettuce will mean you put on
an extra 0.02 pounds of fat. Much of the the rest of the mass will be pooped out. You may keep the water in it for a while, but that too will leave fairly shortly.

1 pound of cane sugar has 1700 Calories in it. That's easy to break down and store, so it will be converted to about half a pound of bodyfat. So you'll store half a pound of mass, and the other half of mass will go out in your urine and as carbon dioxide in your breath.

1 pound of butter has about 3200 Calories in it. You'll break it down, transform it, and store the best part of a pound of body fat. The remainer will go out as carbon dioxide.

There is another aspect, which is volume. How hungry you feel is largely a result of blood sugar, and stomach fullness. Small foods which break down easily leave your stomach quickly, and spike your blood sugar - you feel great after that cookie, but it's gone quickly, so you feel hungry again shortly after. Foods which are bulky and calorie light, such as salads, don't give you that immediate sugar buzz, but do stay around for a while and stop you feeling hungry.

Remember - mass does not equal energy.
posted by ArkhanJG at 1:22 PM on July 30, 2009 [3 favorites]


(and to keep the physics people happy, yes I know mass does equal energy, E=mc^2 etc, but for this problem we need to treat them as separate entities. mass does not tell you what the energy density is)
posted by ArkhanJG at 1:25 PM on July 30, 2009


This is a really common mistake made by laypersons.

Ooh, burn. Might explain why I sucked at dynamics.
posted by electroboy at 1:28 PM on July 30, 2009


I do know this - if you were prediabetic or insulin resistant (like me) a pound of sugar a day would make you fatter than a pound of fat. Why? Because insulin resistant people pump out more insulin in response to carbohydrates than they do to fat and/or protein, and insulin is the "fat-storing hormone." So that doesn't really answer your question for the general population, but for the insulin-resistant population this is how it works.
posted by chez shoes at 1:34 PM on July 30, 2009


I do know this - if you were prediabetic or insulin resistant (like me) a pound of sugar a day would make you fatter than a pound of fat.

Well, this is only true (and I'm making the assumption that it is true since I know little about insulin-related metabolic issues) in relation to the comsumption of other foods beyond the pound of fat and/or sugar. A pound of fat will definitely make you fatter than the pound of sugar when considered on its own, regardless of how you metabolize it or what function hormones have. You're still going to use 100% of the fat as fat, and that has way more calories than the sugar. Even if 100% of the sugar were converted to fat it wouldn't be as much fat as the pound of fat.

While it's certainly practical to consider metabolic issues in dieting, (and this specific medical condition in particular) the mistake most dieters make is to try to figure out the mechanism behind their own metabolism beyond the basic 'calories in - calories out' formula for weight loss. It throws in a bunch of irrelevant variables which need not be heeded if you simply follow the basic advice of focusing on eating less calories and burn more calories. Bodies have an excellent feedback system - if you are gaining weight (over a long term - not because you drank a gallon of water) then you need to eat less and/or exercise more. Doing things/eating specific things which do not contribute directly to burning calories or eating less calories in an effort to manipulate metabolism is a road littered with frustration.
posted by jimmythefish at 1:59 PM on July 30, 2009


To piggyback on this, I've always wondered how efficient the body is in processing what's put into it. For example, if I eat a pound of lard, will my body actually "find" all 3500 calories that are in that glob-o-fat? I assume there is some percent (perhaps tiny) of the potential calories that are missed and simply excreted without being processed, or is the body just very very efficient in converting raw materials into useful things?
posted by maxwelton at 2:11 PM on July 30, 2009


Because insulin resistant people pump out more insulin in response to carbohydrates than they do to fat and/or protein, and insulin is the "fat-storing hormone."

Actually, everybody has a higher insulin response to carbs over fat and protein. Insulin isn't exactly a fat storing hormone either. A quick look at the Wiki page for insulin gives a much better understanding.

Like most of the statements here the answers or questions are simplified and don't really take into account the nuances of food, diet, and body chemistry. As seen above the basics of physics although true, don't give us the best answers. So I agree with the idea that 'calories in/calories out' is a fundamental and easy to follow guide, but obviously leaves out plenty of small type that should be read as part of Human: The User Guide.
posted by P.o.B. at 2:19 PM on July 30, 2009


is the body just very very efficient in converting raw materials into useful things?

This is debated back and forth. Some people think it's a straight across process, others think there is a huge disparity in different people. We know from such things as Diabetes that obviously carbohydrate processing can fluctuate for different people. There's the Biological Value of proteins. Also an overview of human digestion may give you a better understanding. Beyond all that, it's not uncommon that people have undigested foodstuffs in their excreted solid wastes.
posted by P.o.B. at 2:31 PM on July 30, 2009


For example, if I eat a pound of lard, will my body actually "find" all 3500 calories that are in that glob-o-fat?

No, not by a long shot, but digestive inefficiency is already taken into account when converting from calories to weight gained. Eg. if you take in 3500 calories, then your body (running at about 25% efficiency) will obtain about 800 calories from that, which is enough for it to put on about 1 pound of fat.

Hence we say that 3500 Calories is about 1 pound of fat - because all the steps inbetween are beside the point when 3500 calories in still means about a pound in weight gained.

Same goes with exercise - like your car - you measure the caloric cost of exercise and activity by how much fuel is consumed to achieve it, not by how much of the consumed fuel actually gets put to work to that end instead of wasted, vented, or flushed.
posted by -harlequin- at 3:19 PM on July 30, 2009 [1 favorite]



No. Calories are just a measurement of the amount of chemical energy stored in food; specifically:

The kilogram calorie, large calorie, food calorie, Calorie (capital C) or just calorie (lowercase c) is the amount of energy required to raise the temperature of one kilogram of water by one degree Celsius.


When was the last time you took chemistry? And where? kilocalories/Calories are different than calories. A thousand times different.

Just saying.
posted by InsanePenguin at 3:35 PM on July 30, 2009


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