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Why We Get Fat (sciencebasedmedicine.org)
43 points by simonreed on Dec 8, 2012 | hide | past | favorite | 70 comments



"So, why does it get warmer in the summer?"

"Because our hemisphere takes in more calories than it gives off, causing it to get warmer."

"Well, I mean I suppose that's true in the strictest sense, but is there a reason we can come up with tha--"

"What, you don't believe in thermodynamics? What a crackpot!"


> "What, you don't believe in thermodynamics? What a crackpot!"

Come back to me when you've heard a few people say that it is physically impossible for them to lose weight regardless of what they do. They think they could be eating nothing but celery and water and still maintain an upwards trend.

Thermodynamics works. That means it is always possible to lose weight, not that it is always easy.

A weight-loss plan that works is an engineered calorie deficit. Calories in-calories out is the basic outline, but you need to get the details right to find a plan you'll stick to long enough to have a decent impact.

You can engineer a calorie deficit through diet only, exercise only, or a mix; personally, I had very good results with something that was mostly due to a major change in diet with no change in my exercise habits, which mainly consist of walking for a few hours a day. Other people are actually capable of exercising a huge amount more than they have been and making only a modest dietary change. And there are people in between.

And then there are specific foods. Ultimately, no food is bad in itself, and every diet has to meet all your needs, including emotional needs. It can be easier to lose weight and keep it off by banning certain kinds of food, but that is not necessary. Demonizing foods is psychologically unhealthy because it leads to a sin-guilt-redemption cycle that inhibits a rational approach to this engineering problem.

My point, again, is that once you get the details worked out, as long as you actually are in a calorie deficit you will lose weight. There is nothing more to it. The fad diet pushers can fuck off.


I agree with your remark, but would like to make an addition: apart from diet and exercise, there is a third variable that controls the calorie balance: culture/customs. For example, the amount of clothing one wears and the temperature at which one keeps ones living quarters in winter affects calories 'out', as does what one does while waiting for a cab/train/appointment (standing still vs walking around). Those are areas where I think easy gains can be made, even when forgetting about the elephant in the room 'get out of your car', which, apparently, is very hard to do for many people.

And, as with all dieting related stuff, for most people, there is no need for drastic action. Gaining 3 grams of body weight per day brings you 20 kg extra body weight going from 20 years to 40 years of age; that is what happens to most people. Your diet/exercise plan, similarly, is good enough if it leads to 3 grams of weight loss a day.


Except that it's not that easy. Your body will conserve energy if you're hungry, making you feel colder and more lethargic. If you go without a sweater, you'll burn more calories and end up eating more.


I think the point is to be healthy over being thin. Some people have bigger bodies and have a metabolism that leads to them carrying more weight. There's nothing wrong with this. I mean, obesity is another thing in itself - nobody is naturally obese unless they suffer from some sort of medical condition, but the point is if we eat healthy - a decent amount of nutrients without going hog-wild, avoiding shitty processed foods, and also doing a good amount of physical activity, it will make our bodies happy and we can be healthy. I do hate the social pressure to conform to some sort of mythical perfect body, but at the same time I think looking after your body - not starving or totally over-indulging it is important.


>Ultimately, no food is bad in itself

I think that may have been true at some point. But I believe that we are now manufacturing foods that are legitimately bad. Unless you are not counting those things as "food", which I would totally agree with.

I like Michael Pollans's advice: "Eat food, not too much, mostly plants." And "food" here is defined as you would expect (hint: Twinkies don't qualify) In the Michael Pollan definition of food, there is no such thing as bad food.


> Ultimately, no food is bad in itself.

Unfortunately, this completely depends on what your definition of "food" is.


The big mistake begins here:

"Simple physics requires that to lose weight, we must burn more calories than we ingest"

THAT fallacy is how the author leads the reader in to HIS strawman argument, that somehow Taubes is unaware of, or disregards, the laws of thermodynamics.

1) Ingesting calories is not relevant, digesting is.

2) We don't "burn" any calories whatsoever. We use various components of food as raw materials for various biological processes. One conceptual example: when you ingest some sort of protein, your body might break it down in to amino acid chains and then repair a muscle fiber using those raw materials.

Talking about the human body as if it is a closed system that burns food is just silly. We're accidentally taking our metaphors as literal. Yes, if we literally burned all the calories we ingest, the thermodynamics argument would be correct. However, that just a metaphor, don't mistake the map for the territory.


The calories in/calories out model does work as long as you properly count the calories going in. The number shouldn't be what's on the nutrition label since that assumes an ideal digestive system that can fully extract all the energy from the food that a person eats.

This number doesn't include factors such as the health of the person. If the person has digestive problems such an a malfunctioning intestine and can't digest and absorb the energy from the food, then amount of calories extracted from the food will be lower than what's on the label.

If the person has metabolic problems such diabetes or certain other hormonal imbalances, then the energy will be extracted from the food, but it will be stored as fat rather than being used as useful energy. The person will feel tired even though they are consuming enough calories.

Reducing food intake or increasing energy consumption will help a person lose weight if all other factors stay the same. However, as a person consumes less food, they might end up feeling tired and crappy due to the body trying to compensate. Alternatively, changing a person's hormonal balance (e.g. by consuming low glycemic load foods to reduce insulin spikes and allow better utilization of energy in the food) will also cause a person to lose weight. This is the basis of the good calories/bad calories model of dieting, the Atkin's diet, and Tim Ferriss's Slow Carb Diet.


* > 2) We don't "burn" any calories whatsoever.*

- It seems like you would know this but we very literally do "Burn" all of our calories that go into heat production -

The Mitochondrial pathways very literally burn/react carbon with oxygen to produce H2O and CO2 incredibly efficiently. (67% of usable energy from this reaction is captured and stored in ATP, the remainder is given off as heat)

This process is significantly more efficient than any 'burning' we do in industry for example, but is exactly the same process as what is happening in a coal power plant, just on a much more efficient scale.

Even if we take proteins -> amino acids -> back to proteins, we are using energy in the form of ATP (the cellular battery) that was the product of the burning in the mitochondrial power plants, in order to have allowed the amino acids to be ready to be formed into new protein.

So we literally DO burn ALL of our calories (You could argue that glycolysis isn't burning, but this process is very inefficient and is responsible for <<<0.1% of ATP production) This is undeniable scientific fact.


Cool explanation. I didn't conceptually get that the mitochondrial energy process is the same as a coal power plant. But if everything gets burned, how do I build new cell walls and stuff? Where does the actual matter come from?

Some of the matter must be used to create matter directly, rather than as simple an energy source. Or if all the matter in my body is grown/created entirely from energy and cell division (can't be true of essential vitamins, minerals, amino acids, and fatty acids, by definition) isn't growing and repairing my body going to be a huge factor in energy consumption?


Thankyou. It is quite amazing and fully understanding it carries a sense of deep beauty and appreciation for the complexities and interdependencies by which our body sustains life.

re your question: You have 2 overarching (and this is simplifying slightly) thermodynamic gradients operating in the body: Catabolism and Anabolism.

Catabolic processes break down polymers (of which everything is composed). For example: in the Carbohydrate family, we have Starches or Glycogen; a polymer of Glucose monomers. In the Fats family, Triacylglycerides (TAGs) and Fatty acids are 3 and 2 polymer complexes of the standard 'fat' chain. Proteins are polymers of the 20 biological amino acid monomers, which are combined in an infinite variety of combinations and lengths to create the different structures of our body.

We break Fats and Carbs down to their monomers to ingest them into the body (enzymes etc in the Gut). Malabsorption here will result in excess nutrients in our GIT which bacteria can then feast on, causing medical symptoms of maldigestion. Bacteria also operate in a complex synergy with our GIT to keep everything 'regular' however that's far beyond the scope of this discussion, and pushing the limits of the understanding of science even.

Further catabolic processes go on to take fats and carbs down to the burning stage in the mitochondria, which results in the production of ATP, the body's fuel source (you can think of carbs and fats as the crude unrefined elements and then ATP is the refined, useful fuel which every source in the cell which requires energy can utilise)

Production of ATP is in itself a Anabolic process by definition, as it is a more energetic molecule than it's precursors. Note that the production of ATP is coupled to a catabolic process, the burning of carbon in the Krebs Cycle inside the mitochondria.

ATP is the energy source which is then utilised by different proteins in the cell to provide the energy to catalyse the formation of monomers into polymers - this is the process that creates structural proteins, the elongation and duplication of DNA, elements of the Phospholipid Bilayer (the cell membrane - which has 2 fatty acids/fats as the tail) and all the other cellular components.

Note that Anabolism is an energetically expensive process, as you are building molecules which have more energy than the precursors, and so you require a fuel source for this. this is really what we mean when biologists say that the whole system is driven by thermodynamics.

---

TL;DR - We break everything down into it's monomer subunits to get it into our bloodstream. Special transports exist for Amino Acids, Vitamins, Nucleotides, Simple Carbs, Fats etc. Once inside, our protein cellular machinery stores some energy (in Glycogen or Fat), Burns some energy (Energy consumption is coupled to energy expenditure at the mitochondrial level - rate of production of ATP is limited by rate of consumption; O2 is the limiting factor when consumption is high), and uses amino acids and fats, and carbons from Carbohydrates as different structural and functional components in our cell.

So yes, you are right, we don't burn everything to H2O and CO2. But essentially everything that produces the useful energy in our body does go through this process.

I hope this sort-of answers your question even though I got a bit side-tracked


Lay(wo)man's understanding: You burn the oxygen, one molecule at a time. But there is more in your food than oxygen.


I think you mean carbon instead of oxygen, and it's 2 at a time, not one at a time.

Your analogy is roughly correct but in the base, reductionist biochemistry of which the body functions, you have fats (chains of carbons with hydrogens on them - directly burned this way), carbs (basic form C6H12O6) which are also directly burnt this way with water coming off, and protein, which has occasional nitrogen atoms and some sulphur atoms. Proteins can also carry metals - so bits of iron or copper or other things we need to make some proteins function correctly are 'carried' into the intestinal system this way. The only other thing we really need is lots and lots of Phosphate, which we take in largely through consumption of DNA in things we eat

If proteins are to be burnt in mitochondria the nitrogens are converted to urea and excreted.

Vitamins are just arrangements of carbon atoms with the occasional nitrogen and oxygen and hydrogen around. Some have a single copper or zinc atom there too.

We really don't use any more than this, our body literally does just run on carbon. To complete your statement, although there is more in food than just carbon, there really isn't much that we are interested in (biochemically speaking) than the carbon, although the body has uses for some of the myriad forms that are created in other plants and animals that we can't synthesise ourselves.


You know, I feel really crappy today. I am not finding anything that readily matches my recollection of the process, though glycolysis and atp come up in my search and that partially matches my memory. Maybe you could link me to something that fairly clearly shows what you mean? My understanding is "burn" = "consume oxygen".

Thanks.


burning is oxidation, and oxidation requires O2 (although it doesn't always require O2 -oxidation chemically speaking is stripping Electrons and Hydrogen atoms out of a molecule. Which liberates energy.

So you are right. My take on your comment was that you had confused Carbon and oxygen... Since Carbon is the fuel and Oxygen is the oxidising agent , and the convention is basically to talk about the fuel as the one that is being consumed.

I don't have any videos or anything but if you are interested I have attached a link to my old biochemistry notes which, especially if you have a rusty background in anything resembling science, should hopefully jump you along a bit

http://sdrv.ms/SHJQHs


Thanks. I will try to look for something some other time to clarify my understanding. Some time when I feel less crappy.


There's also the distinction between "losing weight" and "losing fat."

The calorie in vs. calorie out method is great if you're simply focused on losing weight, but if you're interested in losing fat, changing your body composition, or gaining muscle definition, you're going to have to dig a little deeper than just calorie counting – you'll need to look at the quality & types of foods you're eating.


Was waiting to see someone to make the distinction between ingestion and digestion.

Most people would consider me skinny... and I always eating and often things that most would consider fattening or unhealthy. People will remark, "How do you stay so skinny?! You're so lucky!"... Except, I would be willing to bet that I have a digestive disorder. Which one? I don't know and I don't care to find out. For the most part it hasn't/doesn't adversely affect me.

It seems that much of what I eat doesn't get digested and/or absorbed by my body.

tl;dr; There's a difference between ingestion and digestion. I ingest a lot but probably don't digest much of it.

Update: I have strong reasons to believe I have a digestive disorder since they run in my family. Also, I wonder how many calories I burn from being a "leg shaker".


I am someone who was diagnosed late in life with a condition which includes but is not limited to a digestive disorder. I have trouble with the idea that you can have a digestive disorder and see no real problems from it. From what I gather, they typically have serious problems associated with them. So it makes me wonder if you have some seemingly unrelated health issues?

You can email me if you would rather not say publically.


going to take this on a slightly weird angle here:

Does your faeces float or have oily discharge around it?

Malabsorption of fat is essentially defined by the clinical features that can be easily determined.

Do you get bloated, have excessive flatulus, or discharge? All signs of malabsorption as well.

It is relatively unlikely that people have digestive problems long term without developing consequences as there are pretty much always side-effects from having nutrients running around a 20m track inside your body loaded with bacteria but not being taken into your body.

What you don't absorb, your bacteria will run riot on, with subsequent symptoms;

And if you have a fat malabsorption problem you will rapidly develop symptoms (see http://en.wikipedia.org/wiki/Olestra or http://en.wikipedia.org/wiki/Lipase_inhibitors for induced fat malabsorption)


He's also completely overlooking the overfeeding studies that Taubes references in his books. Eating 10000 calories of cheese or pork chops is a lot harder than with ice cream.


It's easy to eat a stick of butter and a cup of sugar in the form of frosting.

It's really hard to eat the equivalent calories in butter alone.


Too many times have physicians, from my point of view, fall short of common agreement with regards to my health, especially when it comes to nutrition. I tend to be skeptical of their opinion on the matter, more even so since I switched to a paleo diet and literally dropped the weight that I was supposed to be "genetically" stuck with. So have several of my friends around me.

I doubt the answer is as easy as some would like it to be, but empirically it seems low carb diets have tremendous benefits. I'd recommend reading the Primal Blueprint (http://primalblueprint.com/) for a more thorough explanation of the theory behind it, I'll stick with with my current diet as all indicators (including regular doctor checks) show a drastic increase in my health.


Doctor here. I agree with you about being skeptical of physicians' nutritional advice; we generally aren't nutrition experts and internists, especially, are jaded by the vast number of hospitalized patients we see who have simply abused their bodies with food and drink for decades.

That said, you echo an argument that's as useless as me telling patients "calories in < calories out": that you switched to X diet and dropped weight, just like "several of your friends." That's doesn't provide utility to any public health stance. Of course, I will freely admit that I don't have the answer, either.

What I tell my fat patients who are starting out is this (and I use these exact words): eat the same shit you're eating now, just cut it in half. For educated, motivated people who aren't in denial (which I'm convinced represents < 10% of my patients), we have a more in-depth discussion about dieting ideas that might specifically work for them.


I lost about 50lbs this year. If someone told me to cut the shit I was eating in half, no way in the world a "diet plan" would have worked. Explain to your fat patients that a diet isn't eating less, its eating differently. And three words to end this: slow carb diet.


I'm pretty sure the calories in/out model works to a certain extent. But the paleo diet helped me structure my diet in a way that lets me focusing on simple, healthy food, instead of quantities.


Thing is , we don't know if that is due to paleo or due to being mindful of our eating and thus not overeating. So in a way, the diet can mask what really makes you lose weights, I.e. eating less and working out (if you do)

I think the more popular diets stick around because they are balanced enough to not make you sick and complex enough to make you watch how much you eat. The rest is due to personal preferences.


I was a vegetarian for 3 years before that and have been very careful with my diet for all of my adult life. I've cooked most of my meals in the past 15 years and have felt a striking contrast in health since I cut carb out of my diet, including weight loss.


Do you spend almost all of your day in front of a computer?

One more question, do you practice any sport regularly?


I spend most of my days in an office indeed, as I work in tech. That being said, I've always worked out regularly (especially cardio) and biked to work for the past 7 years. I would say switching to "lifting heavy things" instead of focusing on running probably helped too (though it precedes my paleo diet).


While this is highly non scientific and very subjective, my personal experience is pretty much exactly mirroring the article. A high-fat, low-carb diet makes it easy to lose weight and and fat at the same time. While running/pullups/... help with muscle definition and make me feel healthy in general, the weight loss for me seems to be 80% related to the food I eat.

Here are the graphs:

http://i.imgur.com/y0CJJ.png

I lost an additional 4-5 kilos before starting to use the withings scale that generates these graphs.


I fell like there's an awful lot of confirmation bias in people's reports of how well low-carb diets work, just like there was back when low-fat diets were the big fad. In general, any deliberate change in your diet is likely to lead to results, at least in the short term, as you're paying that much more attention to what you're eating. This is similar to the strength of the placebo effect in medical studies; one reason it's so strong is that even the people getting the placebo in the study are getting a lot more medical attention, and are paying more attention to their health.

Now, I suspect that low-carb diets do actually work better than low-fat, merely because it's easier to keep the calories down on a low-carb diet. "Carb-loading" is a popular way for athletes to give themselves plenty of energy to perform for a reason; carbs are the easiest way to boost calorie intake. So if you have an extreme low-fat diet, you wind up replacing the fat with even more calories in carbs; I can't count how many low-fat foods I've seen that just add a bunch of sugar to make it taste better.

But that doesn't mean that low-carb is a magic wand. In fact, it's fairly dangerous in some ways. Low-carb means you wind up replacing the calories from carbs with fats and proteins; a lot of people eat more meat as a result. Eating a lot of meat can increase your chances of getting certain kinds of cancer. I've seen studies that showed that in the long run, low-carb and low-calorie diets had about the same effects for weight loss, but the low-carb dieters were at a slightly higher risk for cancer due to the extra meat they ate.

I actually think that a large amount of the value of low-carb comes from cutting out the worst form of carbs, sugars. There is an awful lot of modern food that is being loaded with more and more sugar, especially given how cheap HFCS is. It's a very cheap and easy way to make mediocre food taste better; so we wind up eating a lot more sugar than our bodies can handle. Avoiding foods that have sugar added can help a lot.

There has also been a lot of diet fearmongering over something else that has traditionally been used to make food taste better: salt. Lots of foods are sold as "low-sodium" ever since people started blaming salt for heart disease. The problem is, most of the reason for that was based on correlation, where causation had never been shown; some groups of people at higher risk of heart disease were eating more salt, but there was never any good evidence that the salt was the reason for the risk. Reducing salt in food has meant replacing it with other things to make the food taste better, like sugars and fats.

There have been an awful lot of diet fads over the years. Many of them lead to more problems than they solve, as people take them to an extreme, and wind up replacing what they're cutting out with something equally bad or worse. And many of them have lots of adherents who proclaim their advantages, due to confirmation bias, while dismissing anyone for whom the diet doesn't work as not doing it properly (the "no true Scotsman" fallacy).

In the end, "eat less, exercise more" is the best way to lose weight. Yes, exactly what you eat can make a difference, but eating less (fewer calories) is a pretty good first step on the way to losing weight, rather than focusing on one particular source and winding up eating more or eating worse by doing so.


"with fats and proteins; a lot of people eat more meat as a result. Eating a lot of meat can increase your chances of getting certain kinds of cancer. I've seen studies that showed that in the long run, low-carb and low-calorie diets had about the same effects for weight loss, but the low-carb dieters were at a slightly higher risk for cancer due to the extra meat they ate."

I have yet to see a true scientific study that attributes cancer to high meat intake. The "studies" that I've seen which attribute high meat intake to cancer are observational in nature, following tens of thousands of people over 30 years, and pretending that the people who ate lots of red meat in the 70's and 80's have the same lifestyles as those who listened to doctors and ate more salads and fish. The kind of person who ate lots of red meat in the 80's was the same kind of person who probably ignored all sorts of medical advice. This inability to control for other variables is why observational studies are horrible. I'm a huge coffee drinker, but I'm not stupid enough to fall for the observational studies which link coffee consumption to living longer. All too often, the people who DON'T drink coffee DO drink soda, which is a simple example of how these ridiculous observational studies can be misinterpreted.


"following tens of thousands of people over 30 years"

That's called a cohort, it's a well studied method in statistics and depending on the size of the sample and the number of studies you can build correlations out of these.

As your sample gets larger the population for the proportion of heavy meat eaters and the rest of your sample tend to normalize in almost every variable[1], that means the median of every other observable variable will be close to the general population's value for both groups, and you can assume that the quantity of meat is the sole variable worthy of analysis.

Mind you that the use of statistics in health and social sciences is because these fields are not physics, we can't find general solutions based on the present state of affairs putting some number on a equation. How many people will get cancer or whatever.

I doubt this was the type of study that are used in this case because a cohort study is really expensive to conduct, generally this type of study is conducted more using the Case-control method which makes than more affordable.

The fact that if you conduct such a study and find that heavy meat eaters get more cancer or heavy coffee drinkers live more doesn't mean that every coffee drinker will live more or that there will be much more heavy meat eaters with cancer than the rest of the population, it will only means that some epidemiological indices are higher in a group than in the other.

If you really wish to test both hypothesis you must do the same study as many times as you can and try to use the median of these indices obtained in the same study for both populations, the median is a robust measure and see if they are too distant numerically one from the other.

Of course, this can still proves nothing and only find that correlations are in fact established. It can simply be that rich people live longer and get more cancer than the rest and both drinking coffee and eating too much meat be associated with income.

[1]: That's not exactly true you can have confounding variables in your data, which sadly sometimes are not included in the data, when they are you could read the methods of controlling this developed by Mantel and Haenszel.


> In general, any deliberate change in your diet is likely to lead to results, at least in the short term, as you're paying that much more attention to what you're eating.

The graphs in my original post were over the course of a year


>> Rather than jumping on the low-carb bandwagon before his ideas are properly tested, the precautionary principle suggests that it might be more reasonable to follow a moderate diet like the Mediterranean diet (or to follow Michael Pollan‘s stunningly simple advice to “Eat food. Not too much. Mostly plants.”), to limit “empty calories” from simple carbohydrates like sugar, to eat a variety of vegetables and fruits, to choose low calorie density foods that are more filling, to limit meat intake, to limit salt, and to keep looking for behavioral and environmental ways to change our calories-in/calories-out balance.

Ummm, why does the precautionary principle state that we should avoid Diet X (Mediterranean Inuit, Vegetarian,...), rather than Diet Y?

Doesn't the precautionary principle really say that nothing should ever change, since we can always gather more data to further remove risk? (Except, of course, the things the speaker really wants to change, in which case the principle won't be invoked.)


The Mediterranean, Inuit, and vegetarian diets (and presumably also the Pollan diet) are empirically well tested, because many people already live by those diets. This makes them conservative choices. There's no guarantee that they will work, but there is a high probability based on empirical evidence.


I challenge the author to load himself on steak and saturated fats and no carbs and come race me 100 miles on a road bike.

I burn in excess of 4000 Calories on a 80 mile bike ride. That's a kilogram of rice on a single ride. And honestly I find it incredibly hard to eat enough just to satisfy the energy requirements of racing. Not eating carbs and attempting an endurance race event is just suicidal and guaranteed way to abandon and not finish at all let alone place well.

Eating large proportion of your energy from meat is also a good way to kill racing performance, let alone if all your energy is from meat.

But even for sedentary lifestyle, no complex carbs at all is sure way to make yourself feel completely miserable. On the other hand living on saturated fat and protein is a sure way to give yourself a coronary disease.


Compared to the average person, you're a bit of an outlier. If you're not racing 100 miles, why would you consume those carbs?

If you've read Taubes' writing, he doesn't say to eliminate all carbs. He does, however, demonize "white" carbs that have become a staple of the modern western diet.

Even Tim Ferriss' "slow-carb diet" features legumes heavily, but eliminates sweets, bread, and other high-glycemic calorie sources.


I was deliberately flippant in my answer. Of course I would need to challenge one of my racing buddies who are on the same level as I am. But no need for that, I have tried some low carb diets (described in Ferriss' four hour body book) in the off season to try to lower my weight, and even though they work short term (I can do it for a couple of weeks), the performance on the bike started to suffer immensely. I just can't keep up my watts. But that is to be expected.

I will agree that the modern western diet is a horrible thing. I have grown up eating typical Mediterranean diet with mostly home grown organic ingredients, and I find it incredibly hard to continue to eat like that living in Canada.

I think the biggest problem in North America at least is economical. The fact that certain produce like corn are subsidized by the government to the point that they are so cheap they make it into everything where you would never expect. This means you have to exclude certain foods altogether unless you have the time to make them yourself every time you want to eat them, which is rather impractical.


> come race me 100 miles on a road bike

Because that's exactly what people do every day and what they should always be prepared for. I keep my racing bike and a bag of rice right next to the emergency kit.

Some people are into thousands of miles on a bike, or marathons, great for you, but most aren't. And, beyond enjoyment, there's no reason to be into that, there are better, cheaper and less time-consuming ways to maintain your physical fitness[1].

Instead of 100 miles on a bike, you could do 20 pull-ups, 50 push-ups, some leg rises, followed by an inferno omelete[2], save two hours to do something else, and still likely get better results if you're so worried about that coronary disease.

[1] http://medicalxpress.com/news/2012-09-short-intense-health-l...

[2] http://chefinjeans.com/2012/05/31/cooking-for-single-men-inf...


I'm not too worried about coronary disease, but I am concerned about my brain, my mental well being, Alzheimer's, cognitive ability, depression etc, esp. considering everyone on this site is at a higher risk for all of these due mostly to the stress of the profession and sedentary lifestyle.

Unfortunately, leg rises, push ups, pull ups etc (strength and resistance training in general) do nothing for your brain. On the other hand brain thrives on aerobic activity, esp. higher end of the spectrum near the aerobic threshold. And this is also great for your mood and general well being.

It also takes a decade to develop your aerobic engine (well there are really 3 - 4 metabolic systems available to you when you do aerobic exercise, but some are so short in duration that are negligible and the others respond to training very well). Developing power at threshold (i.e. put out as much power as you can at a level just at the edge between aerobic and anaerobic) is the slowest to develop.

For more on connection between brain health and aerobic exercise see Dr. Medina's Google talk on his "Brain Rules". It's quite enlightening in general

http://youtu.be/IK1nMQq67VI


If you're used to burning carbs sure, since you'll have high insulin levels. It takes time to build up to the point where you're able to burn fat easily.

http://www.endurancecorner.com/Fat_Burning_Essentials2

http://triathlon.competitor.com/2012/06/nutrition/inside-tri...


Peak aerobic performance requires carbohydrates. But most people expend less than 100 calories a day on peak aerobic performance, not 5000.

Carbohydrate-related hormones feel pleasant. Withdrawal is unpleasant. This is a good motivation for a hunter-gatherer, but not so much for someone with an unlimited supply of carbohydrates.


Weight equals calories in minus calories out. This ridiculously flawed concept is why people get fat.

It seems plausible. It's how our bank account works. Sounds like science. But is wrong. And easy to debunk:

Have you ever sat on a toilet?


"Calories out" includes what goes into the toilet.


As I understand it, one of the largest factors in low carb dieting is that carbs are less satiating per calorie than fats and proteins. Also that simple/highly processed carbs are even less satiating, largely because they lack any fiber. So if you aren't counting calories, you're much more likely to eat less on a low carb and high fiber diet.

Regardless of what you do, counting calories will probably be the most effective method for losing weight. And even then, calorie estimations are rough, change based on how the foods are prepared, and highly dependent on biological factors unique to each person.

I'm working on Eat This Much (http://www.eatthismuch.com/) as a way to automate my own diet. It still needs some work to get to the point where I'm never thinking about what to eat, but I've been using it to gain weight very successfully over the past few months. Gaining weight can be a lot simpler than losing it, but it still helps to pay attention to what you eat to avoid putting on fat as opposed to muscle.

</stealth plug>


This is a relevant and very informative video about the impact of sugar on humans: https://www.youtube.com/watch?v=dBnniua6-oM&feature=yout...

I'd say that if you were to just dramatically reduce sugar you'll get results pretty quickly.


This is the best article I've read on dieting:

http://blogs.scientificamerican.com/guest-blog/2012/08/27/th...

IMO, if you eat fewer calories than you expend, you'll lose weight. BUT I do think that you can eat more calories than you expend and still lose weight. Likewise, the amount of weight one loses/gains eating the same number of calories and expending the same number is variable based on the actual person and food.

That is to say some people/diets are more calorie efficient (which in our day and age is generally not a good thing). Additionally, some foods/behaviors are probably more likely to make people want to eat more/less.

We can't cheat thermodynamics, but there are other some things we can do to make us eat less and be less efficient.


> BUT I do think that you can eat more calories than you expend and still lose weight.

Then where does the energy go? The only way you can eat less than you expend and still lose weight is to not adsorb some of what you eat, and doing that, while possible with laxatives use, bulimia, and certain drugs, tends to have messy consequences.


Laxatives really are not necessary to have inefficient digestion or energy storage. There are plenty of skinny people who have a hard time putting on weight even though they regularly eat like hogs.


Gotta love any explanation and suggested resolution for being overweight and wanting to lose it that doesn't mention exercise.

If you exercise enough, your diet doesn't have to be so strict, and you're way more likely to actually lose weight and feel good. Some rough guidelines of eating higher quality foods helps, but certainly exercise or lack of it is much more the root cause of so many weight/health related issues.

Most of the time it's very simple. Basic healthy eating and exercise. The problem has always been people don't want to exercise, and there are consequences to that.


You don't need exercise if your diet is strict enough. Doing it all with diet might be the hard way for you but it was the easy way for me; fundamentally, it is calories in-calories out, but you do have to look at the details, and pick a specific plan to accomplish that goal based on the details.


Oh god, let's have this discussion again.


I know how you feel.


Tangentially, I don't understand why so many articles/diets get written about weight loss. At the end of the day, everything boils down to "eat fewer calories than you expend". Given enough time, this regimen will reduce your weight. Period. End of story.

Why must people continually try to create new weight-loss fads all the time?


>At the end of the day, everything boils down to "eat fewer calories than you expend".

Sure, if you stop eating you will lose some weight, but, you can die of starvation while obese. In animal studies, that Taubes cites in one of his books, it is possible to reduce calories and the animals won't lose weight and it is also possible to add a lot of extra calories and not become obese.

Calories have something to do with it because they are one part of the equation. Calories in does equal calories out. Calories In = Calories Stored + Calories Expended. But, the mistake is in thinking that the law of thermodynamics means that the type of calories in doesn't impact the ratio of calories stored/expended -- the variables are not independent. The content of the food you eat impacts: your hunger, your energy level, fat storage rates, and your metabolic rate, all of which mean that attempting to cut or add calories may not have the expected impact depending on what the food is.


> Sure, if you stop eating you will lose some weight, but, you can die of starvation while obese.

This guy[1] went for over a year on vitamins and water. He didn't die, and he did drop a lot of weight. Actually, "prolonged fasting in this patient had no ill-effects." Though it's probably one of those things you really shouldn't try at home.

[1] http://pmj.bmj.com/content/49/569/203.abstract


Taubes gives the example of rats bred or genetically modified to be fat - if you starve them, the body eats the heart and the brain before it gives up on the fat - the animal can starve to death while still fat. Getting fat changes you - a person who was 400 lbs and diets down to 200 has a very different metabolism than a person who has always been 200 lbs. It's possible that something we've been doing is making fat more prone to stick around than it was in times past.

The hypothesis that the problem is too many carbs is plausible but not proven and the full truth is certainly going to be more complex.

Starvation guy is an interesting data point in any cace.


Because it's not just about the calories.

Among other things, insulin spikes caused by carbohydrates influence how the body stores/doesn't store fat/sugars.

You can eat the same amount of calories in fat and carbs and your body will decide to do different things for both cases.


If you boil down what Taubes is saying you get something like the following:

Consciously counting caloric intake and expenditure and trying to target numbers generally doesn't work for losing fat and keeping it off. A good way to lose fat and keep it off is by restricting carbohydrate intake, which in turn will cause your body to spend more calories than it takes in. The first approach is more difficult than the second, and the second one will also help to keep one healthy in other respects.

...

So basically, it's a weight-loss/health strategy that tries to focus on what you're taking in as opposed to how much food in general you're taking in.


The thermodynamics are straightforward. The amount of calories you eat is a known quantity, the amount you expend is a function of a number of variables.

Perhaps something along the lines of: calories_in(food) => calories_out(activity_level, gender, age, weight, body_fat_percentage, protein, carbohydrates, fat, genetics)

I think the complicated part is altering your environment and/or yourself so that you, on average, don't eat more calories than you expend. That is, to fix the feedback loop to make calories_in equal to calories_out at your desired weight.

It's not the simplest of problems, for instance, two people can do the exact same activities and eat the same amount of food and gain different amounts of weight.

Ideally, people would simply stop being hungry when they had eaten enough food, but if that was true, there would be far less fat people. So what actually seems to be the problem is that the biological system that controls hunger is often miscalibrated. I believe that diets attempt to fix that, to make people feel the 'correct' amount of hunger.

For instance, if sugar caused people to become hungry, or to eat more calories than they otherwise would, or to burn less calories than they normally would, you could create a diet that contained no sugar. The average person, if they followed the diet, would hopefully have a more appropriate hunger level at any given time.


The thermodynamics are straightforward but the mechanisms for energy expenditure aren't.

The body is a dynamic system. It responds to the stresses placed on it and adapts. Remove calorie inputs from the system and it tries to compensate by reducing the calorie expenditure.

Low-carb diets work because they control insulin levels. If you can control/avoid the insulin spikes that regulate the absorption/storage of blood glucose, you can modulate your adipose tissue creation/consumption.

Weightlifters/bodybuilders have known this for a long time. If you're looking for answers and evidence, take a good look at the population that's been experimenting and learning how to effectively build muscle mass and avoid excessive body fat.


This is exactly what people don't understand, these consumption mechanisms vary greatly from one person to another.


What you eat affects how much you want to eat and how much energy your body expends, which is why "eat fewer calories than you expend" is overly simplistic. I'm sure you've come across this argument before, so I don't understand the confusion.


It depends on what your goals are, too.

To get down to a 'normal' weight where you look slender but kind of doughy you can probably just cut calories. If you want to be muscular, lean then it's not so simple.


It is not as simple as doing some backhand checkbook balancing of the calories. Metabolic pathways are not the same for every single individual.


If you are doing exercise for which you need energy, the fact remains that carbohydrates can give quicker access to energy than any other macronutrient.


Isn't this just Atkins?




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