
You Can’t Trust What You Read About Nutrition - fisherjeff
http://fivethirtyeight.com/features/you-cant-trust-what-you-read-about-nutrition/
======
jrapdx3
In line with the point of the article, I can attest to the difficulty of
tracking food intake. It's an experiment I've done several times in the past
20 years. The idea is not only recording everything eaten, but _weighing_
every item consumed to assure accuracy. Doing that for a week is a lot of
work, but also highly educational.

What's interesting, on repetition the experiment has shown 2 somewhat
contradictory results. Day to day there was wild variation in diet, always
found surprises in what or how much I ate. OTOH at the end of the week, the
average daily calorie intake was very consistent/predictable at 2100 +/-100
kcal/day. Of course there was a wealth of info about my diet composition as
well.

I'd understand how very difficult it would be to scale up my experiment to the
point of having enough participants to make it scientifically useful. In fact
I'm not at all sure I'd recommend it to anyone unless the individual was so
committed to the project to willingly put up with its arduous and tedious
process.

However, as a personal nutrition learning tool nothing else I know of could
possibly ever beat it.

~~~
dspillett
* Day to day there was wild variation in diet ... at the end of the week the average daily calorie intake was very consistent/predictable

I think this is quite normal and why people recommend not measuring yourself
every day. The average person's daily calorie burn is generally not as stable
as they think it is unless they are closely following a plan.

You can calculate base rate then add the standard percentage for a normal
relatively sedentary lifestyle to guestimate your normal daily output but that
ignores the fact that you body's daily routine is not fixed. In your working
day you will walk around more or less some days, the difference won't be
massive but if you are micromanaging (which you probably shouldn't: that can
lead to over-worrying and potentially to certain physiological eating
disorders) it counts, your social hours will vary too and probably more so on
a day-to-day basis then your working and "doing nothing" hours, your
environment will vary, particularly by temperature which will affect what your
body does to maintain internal equilibrium, and unless you eat exactly the
same food at exactly the same time every day there are differences there:
different foods take different amounts of time to digest, have their energy
extracted, and have their waste pass on through, have different water content
which adds to the natural variation in what you drink, different amounts of
drugs (caffeine and alcohol for most people) that affect water intake/output
in the body is an issue and so forth. There are extra complications for a
woman: changing hormone levels over the course of their regular reproductive
cycle can make quite a difference to water retention and hunger levels.

Basically: your body's routine does not follow an exact 24 hour cycle - this
is why your weekly diet is a lot more predictable than your daily one, over
the longer time the natural variances average out.

But we do have mechanisms that alter out hunger levels to try make sure things
do even out over time. There are things that these mechanisms don't account
for though: problems such as diabetes and other illnesses that affect energy
absorption and use, and it is generally believed that a high sugar diet
"breaks" these systems because they are geared towards slow-ish release foods
and the energy in compact food high in small sugars is very quickly either
used or stored away (so you have the energy ready for use, but you become
hungry because the food is so easy to break down that it has already passed
the parts that register hunger).

I monitor my intake very closely, having gone (over the last ~30 months) from
~18.5 stone to ~10 and wanting to stay somewhere near there. I weigh myself
every day or two but only really watch a fortnightly average as a key value
because I know there will be daily variations both that are due to either my
routine not being very routine or sometimes are far less intuitively
understandable.

It is actually easier for athletes because they can measure their extra
calorie output with some accuracy, and if you are training a lot then this
output is going to be more significant than the random daily variations. Their
incoming diet is likely to be far more predictable than that of the man on the
street too. I'm not an athlete by anyone's definition but I do exercise
"recreationally" these days (mostly running, some strength/tone work, some
cycling & walking for fun/exercise not just to suit commuting requirements)
and I do notice the results being more predictable in periods when I do quite
a bit of that compared to times when I do very little.

~~~
TeMPOraL
> _I think this is quite normal and why people recommend not measuring
> yourself every day._

> _I weigh myself every day or two but only really watch a fortnightly average
> as a key value(...)_

That's the key. I was always under the impression that the reason for advising
people against weighing daily is because you can't rely on general population
to understand the concepts of moving average and low-pass filtering.
Personally, I try to weigh daily (easier to keep a habit this way), but I care
only about the 7-day moving average.

~~~
jhallenworld
I've discovered that my sneaky digital scale has hysteresis: it shows the last
reading unless the new reading is more than 1/2 pound different.

~~~
TeMPOraL
All bathroom scales are witchcraft.

Analog ones always seem to have the precision of ±10kg and generate an aura of
untrustworthiness around themselves. Digital ones behave as if they were
haunted. Every once in a while, usually when the upward-opening crescent Moon
passes through an astral node on the sky, my digital scale just picks one of
two or three values at random. The values are around 1-2kg apart. I learned to
just step on and off it until it either settles on a single result, or I get
tired and just end up averaging last three or five measurements.

------
wanda
Nutrition is like SEO: lots of studies, lots of claims, lots of data... but
all the claims/conclusions seem to be based on post hoc ergo propter hoc
reasoning and anecdotal evidence where the true reasons for success were
either misunderstood or not known at all.

And both fields have a lot of "experts" who all somehow manage to disagree
with one another.

and then there are some basic/no-brainer principles that do seem to make
sense: don't eat loads of sugar, include a <title>.

~~~
spooningtamarin
This is completely false. Scientific studies, controlled, on nutrition and
health are going back at least 30 years, and in these 30 years you can find a
huge amount of quality research and quality data.

Problem is that no one looks at meta-analyses, no one reports about it. WHO
has reports that are sometimes half-assed and clearly * _put large food
industry_ * neutral.

Just take the newest biggest report on eating processed meat being equivalent
to 3-5 cigarettes per day (cancer up by 18%). They did a meta-analysis on 800
articles, and in those articles and conclusions authors clearly state that
meat can be substituted by alternatives that do not cause cancer, but WHO
decided to skip that and mention that there are health benefits to eating meat
(high iron which is not that high compared to plant sources, B12 which of
course, cannot be found anywhere except animals and fortified foods).

They do the same thing with milk, supplements etc.

~~~
trentmb
> milk

Oh god, I go through a gallon of milk a week- what do I need to know?

~~~
talmand
Current study says it's bad for you. Next study says it's good for you. Next
study says it's bad for you. Next study says it's good for you.

This study is good because group A paid for it. This study is bad because
group B paid for it. This study is good because group B paid for it. This
study is bad because group A paid for it.

And so on. And so on. And so on.

And, of course I'm generalizing.

~~~
noondip
The only studies you will ever find supporting milk consumption are funded by
the dairy industry. I challenge anyone reading this to prove me wrong.

~~~
rhexs
Unfortunately, the medical industry (and their lack of focus on nutrition) has
done a rather poor job illustrating why milk is bad for you. The studies do
support that, but due to poor communication, you get people hand waving away
the results suggesting it will be shown to be good for you next week, i.e.
this thread.

~~~
noondip
I can't help but draw parallels to the 60's, when the causal link between
smoking and lung cancer was absolutely apparent. Yet, most doctors smoked, so
few actually recommended people cut it out. As a result, millions of people
perished or had serious health complications. Yes, it's incredibly unfortunate
the medical authorities have failed us - but it's not entirely their fault.
Doctors receive no nutrition training during their education - none!

------
facepalm
At least I think nobody advises to increase intake of sugar? Maybe just
reducing sugar gets you 99% of the way...

The thing about humans is, they manage to live in all sorts of environments. I
think the Inuit have no access to vegetables at all, meat only? But other
societies probably don't eat meat at all (for example some castes in India,
afaik). So I suspect the human digestive system is actually very adaptive.

Problems may start if you try to manipulate the signals the digestive system
reacts to, as is happening with industrialized, processed food. If you lie to
the system, it can not (always) react in a healthy way. (That's my guess,
anyway).

On the other hand, comparing different societies might yield some valid
insights? If a whole country doesn't eat certain foods? Or what about the
result that general health declined with the advent of agriculture?

~~~
coldnebo
I think you have to be careful because there are two things that need to be
separated:

1) the human digestive tract is adaptable -- this measures the amount of
adaptation the individual is capable of.

2) evolutionary pressure selects individuals who are highly adapted to their
environment (I.e. The others simply die off!) -- this measures the adaptations
of a population towards diet.

Ex: Swedish ability to digest lactose in adults. Asian insulin response to
high carb/rice diets.

It seems that if we really want to crack this nut, we should be looking at DNA
data as well. I.e. This population gets this response with this diet, while
that population has a completely different response.

And yes, unfortunately adding DNA populations makes all of this research even
more complex than it already was.

~~~
facepalm
Absolutely, just because population A does well on some diet doesn't imply
everybody does.

Actually that is for me often a good heuristic to discard most nutrition
advice right away. A lot of recommendations I see include lots of diary
products. Yet 16% or more of the (European) population are lactose intolerant
(even more in other countries). So that advice simply can't be true, and it
seems like a good idea to regard the rest of it with suspicion, too. I guess
that at least shows it is not completely hopeless for the individual, some
common sense might go a long way.

A lot of people are Fructose intolerant, yet the "an apple a day keeps the
doctor away" advice won't die.

Then again there is a lot of fear mongering about milk going on. But the
ability to digest lactose (as an adult) spread like wildfire at some point in
time, seems to have had some evolutionary advantage.

"my body tells me what I need" doesn't reliably work either, because it might
crave for sugar, alcohol and nicotine :-/

Nassim Taleb avoids foods that haven't been eaten by his population for
thousands of years, for example Mangoes. Might be too extreme, but worth
thinking about. Atm there is a new craze in my country about some new healthy
grain from South America. I pass - it seems obvious that people can be healthy
without that grain (because people have survived in Europe for millennia), so
why risk it? So maybe if Bananas were a new fad I would feel the same way, I
only eat them because they were already a fad when I was born.

~~~
maxerickson
There's little to no lactose in many dairy products. Notably, cheeses and
yogurt have essentially none.

(I'm of northern European heritage and lactose intolerant)

What is fructose intolerance? Lactose intolerance is the lack of production of
a certain enzyme (lactase) in adulthood, but I wasn't aware that there were
humans that lacked the ability to metabolize fructose in the liver (which is
what I would expect given the analogous name).

~~~
facepalm
[https://en.wikipedia.org/wiki/Fructose_malabsorption](https://en.wikipedia.org/wiki/Fructose_malabsorption)

I know there are dairy products without lactose, but then the nutrition
guidelines should at least mention the issue.

------
ars
I see two solutions.

You can do nutrition studies on animals that are most like us.

And you can study people in structured environments like the military, space,
or prison and accurately track what they eat.

~~~
TeMPOraL
And the best option I think actually seems to be _mass surveillance_. Just
take that somewhat structured environment, where people stay all the time, and
surveil the shit out of it. _Without telling the subjects_. Task a group of
people to objectively observe and note what is being eaten and how it affects
people's health. A pure observation like this could provide a lot of useful
data, that would be free from biases introduced by subjects underreporting
things or simply changing their behaviour because they know they're being
studied.

~~~
deegles
How about grocery store loyalty cards? A big study could be done by offering
everyone a $x gift card if they fill out a survey about their family, get a
baseline medical test and promise to get another one in say 1 year. Changes in
diet could be induced by mailing them coupons for specific foods and tracking
their use.

~~~
TeMPOraL
An interesting proposal, but I see following problems with it:

\- You have both zero control and zero objective input on what subjects are
actually eating. They can ignore your coupons, they can lie or omit (by simply
forgetting about) what they've eaten. They can buy stuff without using loyalty
card (and probably will, in different stores - just how many people shop in
one and only one store?).

\- The data would be very imprecise - while individuals would do the medical
tests, unless you're targeting singles, their grocery shopping will go towards
the _household_ , and you have no idea who ate what.

\- I'm not confident that mailing them coupons would change their diet, unless
you've got yourself either very poor, or very cooperative subject. The outcome
I expect is that people would mostly ignore the coupons if they don't feel
like eating the thing you want them to.

In the end, while interesting, it seems less precise than the current
questionnaire/journal/self-reporting based approach.

------
henrik_w
I just finished reading "Why We Get Fat" [1] and was really surprised by it.
The research seems quite plausible to me, but the recommendations in terms of
not getting fat are not what I have heard as the common advice.

The advice in short is: avoid all carbohydrates as much as possible, and eat
protein and fat.

[1] [http://www.amazon.com/Why-We-Get-Fat-
About/dp/0307474259/](http://www.amazon.com/Why-We-Get-Fat-
About/dp/0307474259/)

~~~
maxerickson
There are multiple fad diets that are popular in the US that boil down to 'low
carb'.

I often wonder if it isn't anything subtle, just that processed carbohydrates
are incredibly energy dense. 100 grams of sugar or flour has twice the
calories of 100 grams of beef (prepared bread still has more calories per gram
than beef). 100 grams of greens or non starchy vegetables almost doesn't have
calories.

~~~
mod
That's my opinion. I use low carb diets because I go around at a calorie
deficit but I feel full all the time. Protein and fats are very filling.

~~~
noondip
Fat has more than twice the calories of carbohydrates.

~~~
Ded7xSEoPKYNsDd
By what measure? I assume you refer to mass whereas gp talked about the effect
on satiety.

~~~
noondip
By the measure of calories.

> Carbohydrate provides 4 calories per gram, protein provides 4 calories per
> gram, and fat provides 9 calories per gram.

[http://fnic.nal.usda.gov/how-many-calories-are-one-gram-
fat-...](http://fnic.nal.usda.gov/how-many-calories-are-one-gram-fat-
carbohydrate-or-protein)

~~~
Ded7xSEoPKYNsDd
So that's calories per mass as I suspected. Now how much does 1g of carbs
affect satiety in comparison to 1g of fat?

(I'm not aware of any useful studies in that regard, but I'd be very
interested.)

~~~
noondip
Think of it this way - for the calorie price of a tablespoon of olive oil (all
fat, nothing nutritious), you can have a huge, ~10 oz salad filled with
veggies, fruit, whole grains and legumes. Have a look at PubMed for "low-fat
vegan" clinical trials - people are put on plant-based diets with no calorie
restriction and end up losing weight. Also, this recent video does a great job
explaining energy density in foods: [http://nutritionfacts.org/video/eating-
more-to-weigh-less/](http://nutritionfacts.org/video/eating-more-to-weigh-
less/)

------
jordanpg
Putting in a word for common sense, and Pollan's condensed advice: "Eat food,
not too much, mostly plants."

I have been astonished at how just not eating _quite_ so much makes a
difference.

------
bmajz
It's great that Five Thirty Eight called out the lack of rigor behind these
studies. Most of them are indeed shoddy. However, that's not to say that we
don't have a pretty good general idea of what's good for you. Here's a pretty
well-balanced article on the topic, with this awesome TL;DR:

“Eat food. Not too much. Mostly plants.”

[https://www.nytimes.com/2015/04/21/upshot/simple-rules-
for-h...](https://www.nytimes.com/2015/04/21/upshot/simple-rules-for-healthy-
eating.html)

~~~
HelloMcFly
That line by Michael Pollan is the most universally applicable line to any
diet. My grandmother had a similar saying: "Beans and greens first, everything
else second."

------
mokkol
This book really made it much clearer for me: [http://www.amazon.com/The-
Enzyme-Factor-Hiromi-Shinya/dp/098...](http://www.amazon.com/The-Enzyme-
Factor-Hiromi-Shinya/dp/0982290039)

Advise of a doctor called Hiromi Shinya, who studied/observed intestines all
his live. He is one of the best in his field and the explanations he gives in
his book are really really logic and inspirational. I highly recommend it, it
changed my perspective of food. Counting calories never done it for me. Not
all calories are not the same.

Hiromi Shinya also made it clear that we only think about our outside and not
about. The inside and the inside is all what counts to stay healthy and live a
long live. You can be thin and extremely unhealthy. It is the inside what
counts and we shouldn't exhaust our organs.

------
Gatsky
As a science I find nutrition grossly deficient, despite food being so
obviously important and occupying so much of humanity's attention.

It seems that something like this would be at least as good as food diaries:
[http://www.digitaltrends.com/photography/google-calorie-
coun...](http://www.digitaltrends.com/photography/google-calorie-counter-
news/)

EDIT: Can't find any trace of it since that one press release in June 2015.
Looks like it isn't being developed.

~~~
stinos
_As a science I find nutrition grossly deficient_

Imo it's not really the science itself, but rather the results which are
deficient and the article lays out pretty well _why_ that is. That, combined
with the _huge_ amounts of pseudo-science and almost-religious takes on what
and how to eat (esp. by people who read a popular food book and think it is
The Sole Truth) definitely creates an image that the whole of food science is
utter BS.

 _It seems that something like this would be at least as good as food diaries_

It would be relatively easy to test properly how correct the calory estimate
is. Which wouldn't be bad maybe, I know a bunch of people who sort of swear by
it for estimating clary intake. (not sure if it's the same app, but they
definitely use something like it. And also tend to think everything it says is
100% correct..)

~~~
legulere
Don't forget that there's also tons of misinformation spread by companies that
have an interest in it: coca-cola spends millions to tell us that drinking as
much cola as we want is okay as long as we exercise enough. But they don't
tell us the ridiculous amount of exercise we would need to do to burn the
calories of a small glass of cola.

~~~
phalangion
It's not really a ridiculous amount of exercise for a small glass of soda. A
can of Coke has 140 calories. 30 minutes on an exercise bike will burn around
300 calories for an average sized man. So it's around 15 minutes of exercise
to burn off a Coke. Hardly a ridiculous amount.

~~~
Vraxx
Fair point, but a small glass of soda isn't exactly the typical serving size.
Go to any gas station and that small glass of soda option got turned into 3 or
4 as your default option. As for the claim of drinking as much as you want as
long as you exercise, I could see that easily getting out of hand with those
types of conversion ratios.

------
mbrock
David Chapman wrote about the pseudoscience of nutrition in context with
scientism:

[http://meaningness.com/nutrition](http://meaningness.com/nutrition)

An older essay on a similar topic, with a critique of cognitive science too:

[http://meaningness.com/perfection-salad](http://meaningness.com/perfection-
salad)

~~~
cableshaft
Perfection Salad explains a lot about the attitudes of my parents and
grandparents about food and how it seems so contrary to more modern
"knowledge" about nutrition. How Crisco ever came into existence and was once
popularly used finally makes sense to me.

Also the actual Perfection Salad, basically a salad encased in a jello mold,
looks pretty disgusting.

------
the_economist
I can use diet to cause or fix acne in myself or another person in a week. It
works every time.

People who don't eat western diets don't get heart disease, acne, or many
other inflammatory related conditions.

Just look at this study Loren Cordain ran in Papua New Guinea:
[http://www.ncbi.nlm.nih.gov/pubmed/12472346](http://www.ncbi.nlm.nih.gov/pubmed/12472346)
\- 0 incidents of acne in the entire cohort.

Pinning down the long term effects of individual nutrients is very difficult,
but we know a lot more about the positive and negative effects of diet choices
than this article lets on.

~~~
brandonmenc
Acne is thought to be largely genetic [1], which could explain why no one in
that study had it.

Anecdotally, I had cystic acne as a teen and was cured after a single cycle of
Accutane. It never returned, even though I kept eating the same diet - which
included a lot of dairy and a lot of fast food.

[1]
[http://onlinelibrary.wiley.com/doi/10.1111/bjd.12149/abstrac...](http://onlinelibrary.wiley.com/doi/10.1111/bjd.12149/abstract;jsessionid=3A9F532B7ADB09F31B44D85A25CE3811.f02t02)

~~~
the_economist
Sugar is the real culprit when it comes to acne.

~~~
brandonmenc
As far as I understand, sugar and carbs _may_ worsen existing acne, but do not
necessarily _cause_ acne.

~~~
the_economist
The pathogenesis (cause) of acne is still unknown.

However, you can take 80% of human beings, feed them nothing but sugar,
deprive them of sunlight and sleep, and they will have acne within a week.

------
hias
I counted my calories for a half year and successfully lost 14 kilos. But
since I like to feel full and I enjoy eating I only ate foods with low
calories/gram ratio. These foods are generell also healthy as well.

Calorie-couting definately works, you just have to be honest with yourself and
count everything you eat and measure always exact.

I recommend you workout a bit while doing this though, I lost not only fat but
muscle mass and my daily calories intake my body need went down about 400
calories.

~~~
enraged_camel
>>But since I like to feel full and I enjoy eating I only ate foods with low
calories/gram ratio. These foods are generell also healthy as well.

Yes. Berries are great for this, especially blackberries. They have very low
sugar compared to other fruits, and high fiber. So they are good for satiety.
They go bad relatively quickly though, and tend to be expensive out of season.
:)

------
cauthon
Lemonade is associated with a positive belief that Crash deserved Best Picture
and iced tea is associated with a negative belief that Crash deserved Best
Picture. I wonder what the consensus on Crash's Oscar is among Arnold Palmer
drinkers.

------
justncase80
The only diet advice you'll ever need:

[http://muller.lbl.gov/TRessays/22-ThePhysicsDiet.htm](http://muller.lbl.gov/TRessays/22-ThePhysicsDiet.htm)

------
np422
According to the statistic available the number of drowning accidents among
children and sale of ice-cream is highly correlated, we must take measures to
lower sale of ice-cream, please think of the children!

Most of the time a journalist will easily believe a statement like above and
rewrite into a newspaper article.

And soon thereafter official recommendations and legislation will follow.

I'm looking forward to [http://nusi.org/](http://nusi.org/) publishing some
results, they appear to be intellectual honest.

~~~
plafl
I'm always wary of articles that try to support their point by showing some
ridiculous correlations. It's very easy to look at thousands of correlations
and select the few most ridiculous, ignoring the vast amount of them that
maybe make sense. Suddenly it seems like statistics are irrelevant and we
cannot trust anything. I suppose that nobody is free from personal bias since
even Fisher, yes the great statistician, rejected correlation between smoking
and lung cancer as a spurious correlation (look up in Wikipedia)

~~~
TeMPOraL
> _It 's very easy to look at thousands of correlations and select the few
> most ridiculous, ignoring the vast amount of them that maybe make sense._

The reality is in fact reverse. Out of thousands of correlations you could
pick, only very few actually make sense. It's trivially easy to find - or
accidentally stumble upon - a meaningless correlation.

------
wmnwmn
There's no value in nutrition studies that don't identify an actual physical
mechanism for the effect. Virtually all past and present nutrition advice is
just superstition. Since we are only just now gaining an understanding of the
microscopic mechanisms that actually run the body, we can hope for truly
valuable nutrition advice in the future.

------
sangeronimo
nutrition/fitness arguments are always so hilariously awful in this website

~~~
trowawee
TFA: "Most nutrition advice is based on badly-structured or (possibly
willfully) misinterpreted studies."

TFC: "HERE'S A STUDY THAT PROVES THAT
PROTEIN/CARBS/FAT/FIBER/VEGETABLES/VEGEMITE/GUM IS THE DEVIL AND GIVES
EVERYONE BRAIN CANCER!"

------
xcambar
But can I trust a nutrition article about the need to avoid trust in nutrition
articles?

It's the liar paradox all over again.

~~~
TeMPOraL
It's not a nutrition article, it's a _statistics_ article. From 5:38. They
have a pretty good reputation so far. That's besides the fact that their point
is absolutely obvious, and the biggest value of that article is that some
widely recognized outlet put the problems with nutrition "science" in terms of
actual numbers.

~~~
coldpie
Just FYI, "538" is a reference to the number of electoral votes in the United
States, since the blog was born while covering the 2008 presidential election.

~~~
TeMPOraL
Thanks for the reference. I didn't know where it came from, but since posting
the comment above I've learned the correct way to write it :).

