Why Eating Fat Doesn't Make You Fat: Sources | Hacker News Reader

Why Eating Fat Doesn't Make You Fat: Sources

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57 pointsjaybol80 comments

Carbohydrates are the most accessible source of energy for your body, but they aren't the only one. For those interested in the mechanics of how fat can be used as an energy source instead of carbohydrates I recommend looking up Ketosis.

It is a huge misconception that "the more fat you eat the more fat you get." Simply having excess energy intake (from any source) will gain you weight -- although the energy requirements for body maintenance is different for everybody. Having a deficit will lose you weight. Of course it is a little more complex than this, but generalising like this makes it simpler to understand and follow.

Personally I keep a moderately low carb diet (I eat most of my carbs before strenuous exercise) and eat high protein/fat.

- http://en.wikipedia.org/wiki/Ketosis

- Alternate infographic about drinking carbonated drinks: http://imgur.com/w6C0s

Sand.

Interestingly, I was recently on a diet that (along with some basic points system that reflected glycemic index/load goals) utilized some innocuous looking pills... which had, as a main ingredient, silica.

These pills worked... when I ate them regularly, I ate less without effort. On reflection this makes sense... perhaps our overly-cleansed (and refined) diet lacks a very basic ingredient that our digestive tract had evolved to utilize (not unlike birds' gizzards) and is now lacking?

This brings new levels of irony to the "DO NOT EAT" silica packages in various packaged foods.

Wait... really? My instinctive reaction is that sand would not be good for your digestive system, but I guess I don't really know. Was (ahem) excretion an issue?

Can't remember, it was a couple of years ago. I don't remember anything extraordinarily different other than I didn't eat as much.

Cotton would have done much the same, or eating any other indigestible solid. You were filling yourself up (sending fullness signals to your brain based on stomach distention) without getting any calories from it. Paper would have worked as well.

This is the same thing UCSF Professor, Dr. Robert Lustig, says in his presentation, "Sugar: The Bitter Truth" (http://www.youtube.com/watch?v=dBnniua6-oM).

There is also a New York Times article on this entitled "Is Sugar Toxic?" (http://www.nytimes.com/2011/04/17/magazine/mag-17Sugar-t.htm...).

> Is Sugar Toxic?

When an article is written in this form, the answer is nearly always "no", as it is in this case.

If sugar were toxic, nothing that eats fruit could survive.

According to that presentation sugar is toxic, but remember that the quantity matters, too. Alcohol is toxic as well, but a glass of wine won't kill anyone, whereas a barrel might put you in a coma.

As per the presentation, the fiber in whole fruits provides the "antidote" to the fructose.

Whenever i read much of this anti-carb stuff, i'm always concerned about how different carbs affect the body. Taubes always blames the whole lot, but people like Lustig distinctly go after fructose. I get that carbohydrates probably affect the body in a negative light, but I certainly wish they would study sugars independently.

Lustig goes after fructose but points out that fructose and sugar are metabolically equivalent. I believe he does so because fructose is more prevalent in processed foods (cheaper, subsidized, and other policy-driven historical accidents behind this).

Slight correction: sucrose (table sugar) and fructose are not metabolically equivalent.

There's an enzyme in your duodenum which cleaves the sucrose molecule into one fructose and one glucose molecule semi-instantly. In both cases, your body ends up with a bunch of fructose. However, if you're eating table sugar, only half of the resulting calories are from fructose; the rest are from glucose.

"Fructose" in Lustig's case is HFCS. HFCS is (depending on the formulation) ~45% - 85% fructose, with the remainder being glucose, and a typical formulation being close enough to 50-50 that it's a wash. Sucrose is a bound molecule, HFCS is free fructose + glucose molecules.

So, while there are some differences (and I suspect there actually are significant differences between HFCS and table sugar), for the most part, eating a lot of foods formulated with HFCS is very, very similar, metabolically, to eating a lot of foods formulated with table sugar.

Indeed. Carbs are not the same just as fats are not all the same. If you spend your life eating crisco and sugar your body will be affected in much different ways than if you spend your life eating olive oil and whole wheat, even if the quantities are identical.

This is partially why the "glycemic index" is bogus.

that's not quite true. He implicates sugar more than anything as well, and has come around to that more and more over time. His next book is going to be about sugar. Part of the thinking is that while fructose may be causing a lot of problems, the fructose/glucose combination may be especially bad.

Excellent to see this, it's a western myth that eating fat makes you fat. It's carbs.

Carbs are cheap, carbs are bad for you and carbs are often marketed as health food.

We don't need carbs. We evolved eating meat and veg. Meat, veg and water is the perfect diet. It's hard to stick to that diet though as carbs are so highly accessible.

Vegetables are mostly carbohydrates, so I don't know how you can say we should eat vegetables but not carbohydrates.

Refined carbs / refined sugar seem to be the problem with most foods these days. With the fear of 'fats' many food producers replaced the 'fat' with refined sugars to add the flavour with less fat (on paper).

- http://www.globalhealingcenter.com/sugar-problem/refined-sug...

- http://lowcarbdiets.about.com/od/nutrition/a/fructosedangers...

"Sugar" isn't the problem. It's fructose. Hard on the liver, can't even be used by muscles.

That's only partially true, and would still be useless if it were totally true. When people say "sugar", they're referring to sucrose, which is half fructose. Even glucose on its own will spike your blood sugar, which will make it harder to burn fat.

Also, your body converts starch into glucose, so starch can spike your blood sugar the same way. Fiber makes your body absorb glucose more gradually, which is why it's important to eat starch and sugar as part of whole foods, rather than in refined form.

> It's fructose

So fruit is bad?

No, because fruit includes a lot of fiber and releases the fructose into your digestive tract over time. Fruit juice is bad, though. It's essentially uncarbonated soda, and sometimes has a higher sugar content than soda. Compare grape juice to Mountain Dew, for example.

That's somewhat misleading. It's true that in vegetables the carbohydrate:fat/protein ratio is much higher than in most other food sources, however the total amount of carbohydrates in most vegetables is still low. Vegetables are mostly water, but are also a source of a great deal of vitamins and minerals.

For their weight, vegetables don't contain a lot of digestible carbohydrates compared to the carb dense staples that are used world wide.

What about fruit? I know little about our evolution, but I'd be surprised if our ancestors skipped over any fruits they would have found in the wild.

The fiber helps a lot to moderate the hit, though this varies greatly among different fruits.

I keep my heavy carb intake (fruit, whole grains) to mornings and post-workout.

Fruit was available for about 2 weeks a year, so they ate some but not year round.

Fruit is fine, but it's not something you should eat huge amounts of. If you look at people drinking fruit juice, they're eating the equivalent of half a dozen oranges per glass.

Don't make the same mistake of oversimplifying diet that led to the "fat is bad" and "fat makes you fat" myths.

Neither fat nor carbs are "bad" for you. Eating too much saturated fats plus a sedentary lifestyle is bad for your heart, pretty much independent of your weight. Eating too many refined carbs (foods with a high glycemic index) is also bad for you and can facilitate weight gain and potentially lead to other health problems in people who are genetically predisposed (e.g. type 2 diabetes). However, eating a Mediterranean diet high in unsaturated fat and whole grains (fat and carbs) is one of the healthiest diets possible according to a huge volume of research, so just throwing around the "fat" and "carbs" labels is not necessarily helpful.

A lot of that research starts both sets of mice on high carb diets, then draws the wrong conclusions about how the little fat they received affected the groups.

http://en.wikipedia.org/wiki/Mediterranean_diet#Medical_rese...

I agree, fat does not make you fat, but carbs will not make you fat either. Excessive calories make you fat. Excess calories from any macronutrient will make you fat, including fat.

Can you please provide real studies, that do not involve Taubes that say or prove otherwise? Real studies, not blog posts. Pubmed or similar.

Here is a list of studies (some relevant, some not, but still interesting) that you may find interesting regarding diet, fat loss, etc:

http://www.reddit.com/r/Fitness/comments/nv8ip/do_you_have_a...

Also, you might be interested to read Martin Berkhan's low carb taliban's blog post. He is very highly regarded and everything he advises, does, and advises his clients are backed by real studies and science.

http://www.leangains.com/2009/02/low-carb-talibans.html

I'm not the most knowledgeable on these subjects, but I really believe stating, "It's carbs." is an outright lie, unless you can back up this with some sort of study or studies or legit real world proof.

I'm not sure why you would say not Taubes. The reason people like him is because of how relentless he is in quoting real studies and interviewing the actual authors of those studies. There are like 200 pages of notes in the back of GCBC.

Yes, I know this, but have you or anyone you know or can link to that has actually gone through and reviewed the studies in full? Not just picking out certain pieces or statements? From people I have talked to that have, they stated that he had taken out parts of the studies that agreed with his theories or were able to see how the studies were flawed and not setup correctly to begin with.

I'm just stating what I have been told and believe it since it was people in the fitness community that are highly regarded and much more knowledgable than I.

Edit: Spelling.

Have you done the same for every study that points to calories in/calories out? In fact, there aren't many such studies actually. Somehow this was given the benefit of being the null hypothesis, which is an underserved benefit in my opinion and many others including Taubes. One of the other things he does in GCBC is go through the anthropological evidence as well. We know quite well that our ancestors ate a very high fat/low carv diet because they mainly ate the organ meat. I don't think that is actually in dispute. Its also part of the foundation of the whole paleo/primal movement.

At the end of the day, Taubes might be wrong about some or all of what he thinks. But the reason why he is generally well liked on HN, a community of very smart, very analytical people, is because Taubes is highly analytical and highly rigorous in his approach. This isn't some woo-woo magic stuff. I've never met a more methodically and rigorously researched book than GCBC. I can't review every study he cites because that would take 5 years at least.

> calories in/calories out

This is a fundamental law of thermodynamics.

Your body reacts differently to different macronutrients. Thermodynamics isn't the last word here.

Not in the way you think it is. It's true that if you gain weight then you must have consumed more calories than you burned. It is not true that if you consume more calories than you burn that you will gain weight. This is not a closed system. You could literally poop out the difference.

As far as it goes, it is a useless statement anyway. The point of calories in/calories out rhetoric is not about the physics; it's about how animals regulate their weight. You could make the same case that body temperature is about heat in/heat out but that would be missing the point of how humans regulate body temperature. The criticism of calories in/calories out is in this vein. Do you think you control your body temperature by consciously monitoring heat transfer? Then what makes you thinks complex animals control their body weight and composition by consciously controlling their calorie usage and intake?

I certainly haven't been exhaustive, but after reading Taubes' Good Calories, Bad Calories and Why We Get Fat I pulled a couple dozen studies to read. Most were because I found his claims implausible, a few because they were just interesting. A couple times I thought he was full of shit (eg. claiming there's no link between increased saturated fat in diet and precursors to atherosclerosis) and tried to find studies to disprove his claims.

I didn't find him to be misrepresenting studies, and I didn't find research that disproved the claims I found implausible. I was underwhelemed by the rigor of a few of the studies he cited, but he was either citing them as historical curiosities or alongside other, more rigorous notes.

I regularly pull sources for the science I read and Taubes fared far better than usual.

Italians have a very high rate of carb consumption, yet the countries obesity percentage is 1/3 of North Americas.

Regarding 'We evolved eating meat and veg'. Anatomically modern man evolved eating cooked food, namely yams, roots and vegetables. Meat consumption was a relative luxury in man's early years.

>it's a western myth that eating fat makes you fat. It's carbs.

A western myth? I've lived most my adult life in east Asia surrounded by people who eat rice or dumplings 2-3 meals a day. I have yet to see any Asian city with as fat of a populace as the high-protein, high-fat loving western cities.

While Fat may not make you fat, all fats are not alike and some fats may be responsible for heart disease and cancer while others may actually be beneficial. This post by Kurt Harris does a good job of explaining why lumping together all fats is not a good idea: http://www.archevore.com/panu-weblog/2011/1/29/there-is-no-s... (PS: Unfortunately, he doesn't cite studies, but with some googling you can find most of the studies).

Obesity itself is a complex topic and blaming it all on carbohydrates seems too simplistic. Over at whole health source, Stephen Guyenet has written a series of articles on the current state of research on insulin resistance - http://wholehealthsource.blogspot.com/2011/11/what-causes-in... Worth a read if you're interested in this topic.

For those who have not seen it, I highly recommend the documentary "Fat Head (2009)". It covers a wide variety of these issues in great detail but in very entertaining way!

Here's a Youtube link to it: http://www.youtube.com/watch?v=UVEiYwFvKvU

East Asians who eat two bowls of rice everyday must be the fattest people in the world then.

This article is so ridiculous.

It's a common misconception that there are few overweight east Asians: http://www.hindawi.com/journals/jobes/2010/868573/tab1/

Further, much of the population of east Asia lives in poverty or near-poverty conditions. Their portion sizes are small (i.e., total daily carbohydrate intake is nowhere even remotely close to that of developed nations). In fact, half a billion Chinese are living on less than $2 / day: http://en.wikipedia.org/wiki/Poverty_in_the_Peoples_Republic...

Also, east Asians eat whole grain brown rice, not the fried, bleached, processed, white rice that Americans typically eat, which is largely devoid of nutrients and fiber.

For far more detail, visit page 226 of Gary Taubes' 'Why we get fat' book.

sigh yet another chapter in "X is bad for you! No, wait, X is good for you! it's actually Y that's bad for you. No wait, it's actually Z!"

After decades of this I've decided they're all full of shit until someone can come up with extraordinary evidence to the contrary.

I don't think there's been much change in this area, it's been "eat in moderation, eat a balanced diet and exercise" for as long as I can remember.

Yes, but what is "moderation"? What constitutes a "balanced diet"? They've been moving targets for as long as I can remember.

Meanwhile we've gone through endless cycles of "cholesterol is bad", "cholesterol is good", "only bad cholesterol is bad", "sugar is bad", "fat is bad", "fat is good, but saturated fat is bad", "carbs are bad". Eggs have gone through two complete revolutions of being bad for you and good for you. And now the new pariahs include white bread, white rice, and potatoes. Madness.

Here's the message I've been given, maybe it's changed without my noticing but I think it's remained consistent -

balance means giving each variable in an equation similar weight. Eating only one or two food groups is not optimal for health.

Moderation - not eating more calories than you burn throughout the day.

edit - I agree with you about the ever rotating axis of nutritional evil. It's BS. I think part of the reason we go through it though is people ignoring the basic advice I mentioned earlier that's held for so long. Why eat broccoli when I can eat McDonalds? Exercise is hard. ETC

It's not just that; it's the temporal nature of what constitutes a balanced diet (i.e. what the variables are, and what amounts are "correct"). Here's a short history of the USDA Food Pyramid, for example: http://www.healthy-eating-politics.com/usda-food-pyramid.htm... (note: this is from a site pushing the low-carb diet, and is suitably slanted in that direction, but is useful for illustrative purposes)

And that's just in the USA. Every country has their own ideas on what is "balanced".

It's ridiculous to claim that you can eat as much protein and fat as you desire and not gain weight.

And?

Is that the claim being made here?

What's your point?

What's your evidence for this? I've definitely lost weight going on a low carbohydrate diet, and I ate as much protein and fat as I wanted. (I tried to keep the fats mostly "good fats".) Maybe if you don't eat any carbohydrates, you just don't end up wanting to eat as much.

I agree that satiety from your macronutrient breakdown is a huge factor here. But some go so far as to claim you can eat FAR beyond your daily caloric burn in protein and fat and still lose weight. I have yet to meet anyone who can credibly back up that statement.

Part of the point here is that you don't know you daily caloric burn. It's not even possible to measure the calories in the food you eat precisely enough so that you could actually maintain weight homeostasis by literally counting calories. And if you get it wrong by even 20 calories a day? In 20 years you will gain over 40 pounds, by the calories in/calories out way of thinking. Clearly there must be some homeostatic mechanism controlling the weight in humans and other animals in the same way that homeostatic mechanisms control your body temperature. The Taubes argument in a nutshell is that excess carb consumption, especially fructose because of how it causes fatty liver issues, throws that homeostasis out of whack.

Make sure you're not simply stocking up on proteins. This can cause you to lose a lot of water, leading you to believe you're losing 'weight'. You might be, but in this case unfortunately, water != fat. Though if you're just 'eating as much [as you want]', you're probably fine.

Though, in all honesty, I don't care so much for special diets. Me, I prepare my own food and don't eat the refined crap, and I'm as healthy as a horse. My ancestors did not evolve to eat that crap.

I kept the weight off for quite some time, so I doubt it was all water. I also fit into my old jeans. My brother just lost about 75 pounds on a low carb diet. That is certainly not 75 pounds of water! I don't know if he also ate as much as he wanted, though.

I do have to say when I went on the low carb diet, it did make me very cranky for the first week or two.

Did you track caloric intake (accurately) on a daily basis? Do you have a base line estimate of how much you burn?

Eating as much as you want can be different things for different people. I know if you gave me a rib eye and eggs cooked in butter or eggs and bacon I could more than eat my fair share of calories burned for the day in that single sitting. No problem. I've done it, multiple times.

I found I got fatter on a too high fat diet. The amount of food, in quantity/volume, not calories, was less since fat has double the calories of carbs and proteins and I always could fit in more.

No I didn't track caloric intake. Why would I do that? One of the selling points of these low carb diets is that I wouldn't have to track such things -- that all I would have to do is not eat many carbs and that I would lose weight.

I'm certainly not claiming that this style of diet would work for everyone, but it certainly seems to work for many people. One thing I noticed is that when I wasn't eating carbs, that eating a rib eye with eggs and butter and bacon didn't seem nearly as appealing in large quantities as it otherwise would have. The diet did take away a lot of the pleasure of eating, which may be in part why it worked. I just ended up not being terribly excited by foods without carbs in them and consequently perhaps didn't over-eat. I would have killed for a saltine, though.

Another thing I noticed is that I wouldn't lose weight if I ate lots of nuts. It seems likely that the reason for this fact is that nuts are just too high in fat to eat in large quantities and continue to lose weight. But the diet warned against eating many nuts.

In any case, I think the point is not that you can eat any amount of fat and protein and lose weight, but rather than you can eat as much as you will end up wanting. (With the exception of nuts.) And that you won't end up feeling hungry.

It's ridiculous to claim that you can eat as much X as you desire and not gain weight, for most X except maybe celery.

The point is that protein and fat satisfy hunger in a way that our bodies have evolved to process. And the fact is, after eating a bit of protein and fat, you won't DESIRE to eat any more.

Seriously, read this book, it will change your life. http://www.amazon.ca/Why-We-Get-Fat-About/dp/0307272702

Satiety is mainly due to dietary protein intake because of its glucagon activity.

I'm going to get downvoted, I can see it coming. However, it must be said, because I'm sick of seeing Taubes used as reference.

Taubes is a loon.

He picks out pieces of studies to back up his statements to sell more books and make more money on speeches. What he says is basically what people want to hear.

Just because Gary Taubes says it's true does not make it so. Has anyone gone and reviewed the studies in full that he has referenced? Does everyone just take his word for everything he says? There is a lot of love for Taubes on Hacker News. I expected people on here to be much more knowledgable about this topic, but I'm severely disappointed to find out that it seems the majority of Hacker News users fall into the typical American fad diet beliefs (previously, it was no fat and now it's no carbs). What's next?

People who believe Taubes usually fall into one of the following categories being thrown around the fitness community: Ketard, Carbphobe, Carb Taliban, to name some.

Even if that's true, the food industry does all kinds of lobbying and has ties with agricultural companies and has instilled upon us this conventional wisdom that whole grains are great for you and calories in = calories out with no distinction between types of calories.

Yeah, so two wrongs don't make a right, but I think he's justified that he feels like making extreme conclusions will make people question the conventional wisdom that has been steering us in the opposite (and in my opinion, wrong) direction.

Every study I have ever seen that put low carb diets head to head with other diets result in at worst, equivalent weight loss and usually more weight loss, with better other bioindicaters. Unfortunately many of these studies are brain dead in that they only weight body weight and not body composition, but given that other studies have shown that high protein diets lead to better muscle preservation, and a low-carb diet is generally higher protein than a low-calorie diet, I would bet money that even in studies where low-carb diets produce equivalent weight loss they have produced superior fat loss and superior muscle preservation.

I'm going to get downvoted, I can see it coming. However, it must be said, because I'm sick of seeing Taubes used as reference. Taubes is a loon.

Yeah, well name calling isn't a good argument so the down vote foresight was an easy one to call. http://www.paulgraham.com/disagree.html

At least Taubes uses a few scientific studies to back up his point. If you have better science to backup whatever your position is I would love to see them.

Do you think the two hundred and fifty MDs and PhDs that just this month signed[1] his petition[2] are also loons?

Or perhaps you think Walter Willett M.D., Ph.D., and David Ludwig M.D., Ph.D., of Harvard--two of the foremost nutrition authorities in the US--who agree with Taubes, are also loons?

Maybe you think all of these individuals simply don't bother to do due diligence on what they read? Or maybe you think they are suffering from insufficient intellect such that they're incapable of detecting your accusations of cherry-picking and snake oil?

I'm also a bit lost with your characterization of a low carb diet as a fad diet. Surely you understand that this is the diet our ancestors were exposed to during millions of years of hominid evolution?

[1] http://www.ipetitions.com/petition/response-to-nytimes-the-f... [2] http://www.ipetitions.com/petition/response-to-nytimes-the-f...

Not really. Sure, if you're force-fed bacon and eggs, you might still gain weight, but the point is that fat uniquely "sates" us, and that they key word is "desire" -- you stop desiring more food.

In my experience, you can indeed eat as much protein and fat as you desire, and not gain weight, because you literally stop desiring to eat more, significantly before the point at which you would gain weight.

That's what's "special" about refined carbs -- you can keep wanting to eat slice after slice of pizza, day after day. Basically nobody can do that with fatty steak. Just try it, and you'll see what I mean.

Technically, it is energetically easier to store dietary fat as adipose as opposed to carbohydrate.

The problem most people have is that they eat enough carb to satisfy their daily energy demands, and the fat they've eaten will be stored. Keep in mind that almost all muscle tissue and the brain prefer glucose (which usually comes from starch) over anything else, although some vital organs run mainly on fat, particularly at night.

Our digestive system is very efficient. The bottom line is this: if you eat more calories than you expend, you will gain weight.

Your bottom line is true but not actionable, which makes it a poor bottom line. If you want to eat more calories than you expend, you should reduce your carbohydrate intake.

The useful bottom line is the bottom line of the infographic.

I'm confused by your statements. Are you basically saying one can eat more energy than their body burns as long as they reduce carbohydrates?

From my understanding, fats are the most easily stored as body fat of the 3 macronutrients. Carbs and protein offer a great TEF and satiety than fat.

The makeup of your diet, among other factors, determined how the body reacts to the extra calories and decides whether to store it more as fat and/or lean muscle mass.

Oops, I mistyped my comment. I meant fewer calories.

The hidden assumption here is that your body puts forth the same amount of effort to store fats vs carbs. This isn't borne out by the evidence. Cells uptake nutrients in response to insulin. Your body produces insulin in much greater amounts in response to carbs vs fats. This is necessary: free floating glucose is toxic to certain organs. Fats on the other hand can exist in your bloodstream without any acute damage.

are you sure? http://www.empowereddoctor.com/eating-fatty-foods-inflames-b...

Informative, thanks!

We've known fat isn't fattening for years.

Its nonsense.

Insulin.

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