
A Mathematical Challenge to Obesity - ckuehne
http://www.nytimes.com/2012/05/15/science/a-mathematical-challenge-to-obesity.html
======
koeselitz
"Well, what do people do when there is extra food around? They eat it! This,
of course, is a tremendously controversial idea. However, the model shows that
increase in food more than explains the increase in weight."

This doesn't actually follow logically. I know Mr Chow is implying that
there's a lot of data that this interview obviously doesn't present, but there
are serious problems with this thesis on the face of it. For one thing, if
obesity correlates directly with the availability of food, then the _most_
obese people ought to be those to whom food is most available. But the rich in
our society are proportionally not as obese as those who face periodic food
shortages; and low-income children are proportionally shown to be at much
higher risk of suffering from obesity. [1]

Not only that, but the statement that food production has _simply_ gone up and
therefore food prices have _simply_ gone down is incredibly... simplistic.
There have been arguments for years [2] about _what_ food prices have gone
down or up and how that may or may not have affected obesity.

I want to believe that there's data behind this fellow's claims, but I can't
help but feel as though, no matter what the data is, summarizing it in the way
he does is deceptive.

[1]
[http://jama.jamanetwork.com/article.aspx?volume=303&issu...](http://jama.jamanetwork.com/article.aspx?volume=303&issue=1&page=2)

[2] For example, [http://www.good.is/post/the-inconvenient-truth-about-
cheap-f...](http://www.good.is/post/the-inconvenient-truth-about-cheap-food-
and-obesity-it-s-not-farm-subsidies/)

~~~
redwood
The rich can _afford_ to eat at restaurants with routines that simulate a
robust meal without truly ingesting too many calories, and because it's
healthy to do so, this is precisely what the rich do. This is why portions are
so tiny at gourmet restaurants so the middle class balks at them as a total
rip-off. In a sense you pay to be given pomp and circumstance and less food!

~~~
2muchcoffeeman
With a degustation you'll probably have quite a few courses. 9, 10 maybe more.
Maybe matching wines.

If you are just fine dining you will get larger portions but will still go
starter, entree, main course, dessert.

The portions are small because you cannot eat that much. The prices are high
because at a good restaurant they are serving food that is hard to make and
they do it well.

A lot of fine food can be very rich. So I am not sure about not ingesting too
many calories. Perhaps relative to eating an entire pizza on my own. But not
to eating a regular balanced meal.

------
lukifer
Math alone is the wrong tool to solve a problem that is biochemical and
behavioral in nature. On an individual level, the fix is straight-forward: eat
more "good" fats, and little or no grains and sugars. I have yet to encounter
someone who has done this and not seen dramatic results.

It's a trickier problem on a broad sociological level, though. The sugar
peddlers have an incentive to create and maintain the addiction, and yet
they're also just giving people what they want, and at the end of the day,
it's still a free country. We can't ever expect all people to abandon sugar
any more than all people have abandoned smoking.

As much as I hate to agree with libertarian dogma, I think the USDA is a big
part of the problem. They've been been promoting high-carb diets and
"moderate" sugar consumption for decades, and it certainly smells like yet
another government-industrial complex protecting existing profits.

~~~
dkarl
We shouldn't get so worked up about exactly what we eat. When we look around
the world, we see that people who eat a modest diet and are physically active
every day live long, healthy lives.

If we go back to what we would think of as the dark ages of nutritional
knowledge, there were lean, healthy, athletic people back then. And it wasn't
just people who ignored all the nutritional dogma of the day, either. The
people who swallowed it most conscientiously were lean as well. It seems like
so much has changed since then, but has it? Go to the gym today and you'll see
a bunch of people who work out, eat paleo, and have low body fat. Thirty years
ago they'd still be lean and in great shape, but they'd believe an entirely
different dogma about nutrition.

If _what_ we ate was anywhere near as important as _how much,_ then the people
who were most disciplined about following the old low-fat, relatively-high-
carb diets would have been at a disadvantage compared to people who paid no
attention and half-assed it. Or, if the low-fat guys were right, they should
have been leaner than the guys who thought milk and eggs were the secret. But
consistently, decade after decade, people who are disciplined about diet and
exercise are lean and fit no matter what they believe. When people let their
discipline slip, most of them end up overweight to some degree. The entire sum
of our nutritional knowledge has yet to change that.

~~~
stdbrouw
> But consistently, decade after decade, people who are disciplined about diet
> and exercise are lean and fit no matter what they believe.

Proof?

------
csmeder
_"What caused the obesity epidemic?"_

    
    
      "And it’s something very simple, very obvious, 
      something that few want to hear: The epidemic was 
      caused by the overproduction of food in the United 
      States. ...This, of course, is a tremendously
      controversial idea. However, the model shows that 
      increase in food more than explains the increase 
      in weight."
    
    

This is analogous to saying: _"What caused the increase in car accidents?"_

    
    
      "And it’s something very simple, very obvious, 
      something that few want to hear: The car accident 
      epidemic was caused by the overproduction of cars 
      in the United States. ...This, of course, is a
      tremendously controversial idea. However, the model 
      shows that increase in cars more than explains the
      increase in car accidents."
    
    

By using the phrase "overproduction of food" he is using too broad of a
statement that doesn't describe the problem in an addressable way.

It makes it sound like we could just cut food production across the board and
prevent obesity.

.

I would argue the problem isn't the quantity, rather the quality. Quality in
regards to:

\- Nutrients vs Fat and sugars

\- Number of meals a day and the time we eat those meals

\- Sugary drinks vs Water

\- Appropriate meal size

\- Fast food vs home made meals

The solution for the 21st century is going to take more than cutting food
production. Just as curbing injuries from car accidents will take a different
approach than limiting US car production.

~~~
alexandros
> I would argue the problem isn't the quantity, rather the quality

But you didn't, argue. You simply asserted. You threw out the article's theory
by constructing a straw-man you didn't even bother tearing down, then
proceeded to inform us of your views.

~~~
brady747
You are right, but he didn't say he was arguing in his comment, he said he
would. :)

------
Almaviva
"An extra 10 calories a day puts more weight onto an obese person than on a
thinner one."

It needs to be explained how he determined that this isn't related to _why_
they are obese in the first place, i.e. whether these are purely correlational
facts. It would be nice if the New York Times wasn't susceptible to elementary
statistical fallacies like this but... well this is nutrition after all.

~~~
streptomycin
An interview in the New York Times is not an academic research paper. In this
context, it's reasonable for the interviewer to take the mathematician's word
for it rather than hammering away at a pedantic detail that may or may not be
relevant.

~~~
Almaviva
This would be reasonable if people who ought to know better didn't commit this
kind of elementary error constantly, particularly in nutrition. It is your
attitude, that it's reasonable to publish a scientific article in a major
publication without independent thought and fact checking, that I am
challenging.

~~~
scott_s
_it's reasonable to publish a scientific article in a major publication
without independent thought and fact checking_

The person you are replying to did not say or imply that.

------
opiumden
It's nice to see that people are developing new models and ways of thinking
about weight loss but I wonder how effective this research is going to be. The
conclusion of the article is the same old "eat less and eat healthier" which
is fantastic advice ... and advice that a great many people don't bother to
follow.

As a culture we're eating ourselves to death while worrying that low
probability events like terrorist attacks are going to kill us. We're killing
us and we're doing it slowly.

~~~
potatolicious
> _"which is fantastic advice ... and advice that a great many people don't
> bother to follow"_

At least a large part of this is due to lack of education. For all the time we
spend on math and science in public schools, we spend _none_ of it on some
basic principles like nutrition.

I was rather obese in high school, and the (Canadian) government foot the bill
for nutrition courses and consultations with a dietitian (this is a big can 'o
worms too: preventative programs like this are way easier in a single-payer
system).

I now have the ability to judge what's good for me, and what isn't, as well as
effective alternatives to existing choices. That knowledge has been
instrumental in my weight loss.

The problem with that "fantastic advice" is that it's rarely coupled with real
constructive suggestions. "Eat less and eat healthier, fatass" is unproductive
when the person lacks the knowledge to make effective choices, and
alternatives to break entrenched habits aren't presented. Sure, a Big Mac is
universally unhealthy, but what do you replace it with? A grilled cheese
sandwich isn't much better, nor are a lot of "healthier looking" alternatives
(anything with mayo slathered in it is dietary suicide, regardless of how much
greens you stick in it also). How do you curb hunger when in the process of
downsizing your portions? Curling up in a corner isn't super effective. Blood
sugar management throughout the day to get you through the rough patches? None
of this is trivial knowledge.

Of course, the factor making all of this substantially worse is that the
signal to noise ratio in dietary literature is horrific. For every real,
researched book on effective diets, you have 3 more fad diets backed up by
voodoo and pseudoscience.

~~~
krupan
Actually, I was taught a lot about basic nutrition in school. Low fat was
good, complex carbohydrates were good. 4 food groups. Now apparently that is
all wrong?

------
brd
The Omnivore's Dilemma (Michael Pollan) goes into more detail on the history
of the food boom in the 1970s and its link to obesity. Its a great read for
anyone interested. Essentially we got hit with a one-two punch of food price
paranoia and the high fructose corn syrup innovation.

~~~
saddino
I'd also recommend The End of Overeating (David Kessler) which posits that the
obesity explosion is due to recent advances in food science re: foods
engineered (precise ratios of fat, sugar and salt) to make you want to eat
more ("conditioned hypereating").

If you want to lose weight, stop eating packaged food, cut out fast-food and
cut back on restaurants/take-out.

Make your own food (like everyone did 40 years ago for most meals) and you'll
find yourself controlling your portion intake by default.

~~~
wpietri
I second that. In April I tried an experiment: home-cooked meals at least
twice a day, and nothing with a human-boosted glycemic load. E.g., nothing
with added sugar, no refined carbs, no fruit juice.

Portion control was much, much easier. I still ate until I felt full; I just
felt full a lot sooner, and experienced a big drop in between-meal cravings.

------
paul-woolcock
The "calories in/calories out" argument is based on the assumption that the
human body is a closed system. This is simply not the case, and touting it as
a diet strategy is irresponsible. You might lose weight if you lower your
caloric intake by only eating 1 McDonalds cheeseburger a day instead of 2, but
in the end you are still eating crap food "product", and you won't be as
healthy as you could be by focusing on the _quality_ of your food as opposed
to the _quantity_.

~~~
getsat
There's a few National Institute of Health studies that back the calories in
vs calories out argument. Keep your calorie intake below your BMR (basal
metabolic rate) + what you burn during the day if you want to lose weight.
Very simple. You don't have to "balance saturated and unsatured fats", get ten
hours of sleep per day, or whatever other ridiculous microoptimisations people
come up with.

Eat 500 calories below your MBR + burn rate and you lose one pound per week.

You can do it while eating garbage food (fast food, heavily processed food
products) or you could do it while eating a totally vegan diet. It doesn't
matter for _weight loss_.

~~~
Drbble
Look up "compliance" and how it relates to self-applied medical care for
nutrition, acne, exercise, birth control, etc. Vasectomy is more effective
than pill is more effective than condom, not because of chemistry or biology
or physics, but because of psychology.

------
dbecker
I was unable to find original source material by the researcher (only finding
the abstract for his presentation at
<http://aaas.confex.com/aaas/2012/webprogram/Paper6155.html>)

If anyone can find the author's slides or related article, I'd appreciate a
link to them.

~~~
notJim
This is the obesity section of the author's website:
<http://sciencehouse.wordpress.com/category/medicine/obesity/>

He links to the slides from that conference:
<http://sciencehouse.files.wordpress.com/2012/02/aaas122.pdf>

------
mhartl
You are an M.I.T.-trained mathematician and physicist. How did you come to
work on obesity?

 _...I didn’t even know what a calorie was._

I call bullshit.

~~~
DanBC
We tell lies to children because the truth is too hard for them to understand
at their level of knowledge. (See, for example, models of atoms that have a
nucleus and protons and electrons buzzing round it.)

So, with that in mind, children learn that one calorie is the amount of energy
needed to raise 1 g of water by 1 degree c.

But what does that actually mean for a human body? How is a calorie in fat
worked out? How is a calorie in sugar worked out? How do we know they're
equivalent?

~~~
mikeash
> So, with that in mind, children learn that one calorie is the amount of
> energy needed to raise 1 g of water by 1 degree c.

I find this to be wonderfully ironic, because the nutritional calorie is 1000x
larger than the physics calorie. In nutrition, one calorie is the amount of
energy needed to raise 1kg of water by 1 degree C. So yes, it's entirely
possible that this fellow didn't know what a "calorie" was in the realm of
nutrition.

~~~
DanBC
Wait, what? That would be one kilocalorie. And that's what's listed on most
food?

~~~
mikeash
Yep. When you see "calorie" on US food labels, that's actually a big-C
Calorie, or food calorie, which is equal to a kilocalorie from regular
physics.

If it were regular physics calories, the energy content of food would be
nowhere near enough to sustain us. A typical human body at rest will consume
around 8 megajoules per day, or about 2 million calories. But that's only
about 2 thousand big-C food Calories.

Forgetting or ignoring this difference results in amusing things like the beer
and ice cream diet: [http://training.fitness.com/weight-loss/beer-ice-cream-
diet-...](http://training.fitness.com/weight-loss/beer-ice-cream-
diet-1243.html)

------
nazgulnarsil
sugary drinks. I've never known someone to drop these and not lose weight. It
is SO EASY to consume an extra 500 calories a day of liquid sugar. It has
close to zero satiety. A 500 calorie surplus is a pound of weight gain a week.

~~~
jrockway
I gave up sugar a few years ago and there was pretty much no effect. I didn't
have much sugar before, and there are plenty of other sources of calories.

~~~
nopassrecover
Yeah likewise. I almost never have a sugary drink (maybe a softdrink can once
every 3 months) and it's made zero difference to weight. Stress on the other
hand is highly correlated personally with weight (I've lost ~10kg in 3 months
every time I've quit a job).

~~~
nazgulnarsil
wtf guys obviously if you didn't drink a lot of this stuff before then losing
it will have a correspondingly small effect.

Calories in calories out.

~~~
derleth
> Calories in calories out.

Every time someone says that, the people with a hobby-horse to ride come out
and beat on the person for a bit. Especially if they imply that honey (no,
sorry, the correct term now is HFCS) isn't the Devil's own temptation sent to
corrupt and impurify our precious bodily fluids.

~~~
jrockway
Indeed. The reason why _I_ don't like HFCS is because its presence in a
product says, "to make our profit margin as large as possible, we used a bunch
of artifical ingredients that are slightly cheaper than the real things.
that's just how much we care about you, the consumer." Have you ever heard
anyone say, "we use HFCS because it tastes better than cane sugar?" Nope. So
why use it?

------
optymizer
if someone else is having problems launching their Java Applet, but you have
Java installed, download the jar from:
[http://bwsimulator.niddk.nih.gov/WeightAppletv10.4.6.signed....](http://bwsimulator.niddk.nih.gov/WeightAppletv10.4.6.signed.jar)

then run the following command:

    
    
      java -cp WeightAppletv10.4.6.signed.jar weightapplet.MainPanel

------
robomartin

      "And it’s something very simple, very obvious, 
      something that few want to hear: The epidemic was 
      caused by the overproduction of food in the United 
      States."
    

Overproduction? Does a factory intentionally produce more cars than it can
sell? Probably not. How about a baker? Does a baker produce more cookies than
she can sell? Not for long. Maybe a farmer? No. Not really. That is not an
economically sustainable position to take.

If we take the "overproduction" assertion as fact, this begs the question: Why
is this happening?

One answer is that consumers have more money to spend and they are choosing to
spend some of it buying (and consuming) more food. Fair enough.

Another answer could be that, in certain segments, government geniuses decided
they know better than to let free market work. They go in and throw money
around to make producers do what they would not under normal circumstances.
That triggers over-production of certain goods. Which triggers lower prices.
Which triggers higher consumption. And so on.

Another possible answer is a combination of the above. I am, admittedly,
against government meddling in our lives. I want them out of nearly
everything. Go throw parties for foreign dignitaries and balance our books.
Maybe do a few more things. Oh, yes, those borders. Deal with them will ya?
Any time these guys dip their ignorant toes into the water of our lives they
invariably create a mess that our children and our children's children will
have to pay for.

Of course, this philosophy extends to self-responsibility. In my family we
might have a soft drink or two at parties here and there. Just like having
ice-cream, in moderation it is an occasional treat. Aside from that, water
only. What the hell is wrong with people that go into a gas station and order
a 64 ounce soft drink? That's like consuming a cup full of sugar while you
drive to work.

This is where another angle in this equation comes into play: A third-payer
system of health does not penalize bad behavior. Someone who is a complete
moron when it comes to how they take care of their bodies and what they put
into it should suffer the financial consequence of having to pay a lot more
for healthcare. Today, those of us who try to be sensible are paying for the
idiots who are not. That is fundamentally wrong.

If you want a healthy and slim population, again, get government the hell out
of the way. Yes, it can be that simple. Don't manipulate markets and don't get
involved in healthcare. People should buy and pay for their own health
insurance, just like they do car insurance. If you drive like a mad-man and
get tickets and accidents your insurance goes up or it could be cancelled. The
end result is that people modify their behavior to what is a financially
sensible state.

The same would happen with healthcare if people were directly responsible for
their own insurance and suffered the consequences of their dumb decisions.
Smoke and destroyed your lungs? Your insurance should cost you $50K per year.
Enjoy. Drink alcohol like an animal and turned your liver into mush? $75K a
year. Have fun. The rest of us would have sensible policies which would reward
us for being responsible while covering us in the case of catastrophic events
or serious illness outside of our control.

To be clear, I don't have a problem contributing to the pot to help out those
afflicted with cancer or similar horrible diseases. A portion of everyone's
premiums would cover these out-of-the-norm cases. Then there's the case of
obesity caused by diseases like Cushings Syndrome (pituitary gland tumor)
that's potentially deadly and has nothing to do with over-eating. We need to
collectively help those people. Nothing wrong with that.

I do have a problem supporting the moron who has a Double Big-Gulp every day
chased by a large pizza and no exercise other than playing XBox for hours
every day.

That said, the app for the model looks interesting. I had my basal metabolic
rate measured last year before I started a Master's Swimming program. I like
numbers and wanted to have some data. It was 1850 kcal/day. According to the
Human Weight Simulator I have to consume 2576 kcal/day to maintain my weight.
That, for some reason, feels way too high. I haven't counted calories in a
long time, but might do it for a few weeks just to get a sense of what this
model is doing. I doubt that I am consuming much more than 1700 kcal/day on
average. But, I could be wrong.

I'd be nice if they released a paper with this equation the article mentions.
Is that published anywhere?

~~~
Drbble
Http://begthequestion.info

~~~
robomartin
I know. I went back to edit that but it was too late. I meant to say "raises
the question" but fell into an all-too-common trap. This is easy to do in
English if you are not on your toes because the word "question" has two
meanings and "beg", in my opinion, makes it even more confusing. In other
languages, for example, Spanish, the equivalent phrase is not ambiguous at
all: petición de principio

I actually studied Logic in Spanish while my family was living abroad.
Sometimes that does a number with my brain because I actually think about the
fallacies in Spanish!

Thanks for pointing that out.

------
its_so_on
I disagree with the article, and don't believe mathematics has the answer to
obesity.

However, if someone would like to start a diet-centered startup with me, I
believe I have an insight that invalidates every diet book on the planet.

Every diet book on the planet makes one very false assumption. Before we get
to the assumption, let's review something uncontroversial:

\- You put on fat by eating more calories than you use; and you lose fat by
using more calories than you eat.

In other words, losing fat (beating obesity) would seem to be a combination of
"diet and fitness". If you like, you can view every diet book on the planet as
a combination of strategies that fall into those two categories (eat less or
use more of the calories).

So how can ALL those strategies be wrong?

Let's turn the equation "net fat gain = calories in - calories out" into
something more familiar. "net bank account gain = money in - money out."

is it really so simple? Yes. Everyone who weighs more than they want has more
money in their bank account (more Calories on their body, ready to burn off)
than they want.

Now to get to the big diet books' fallacy, let's turn this around. You're a
multimillionaire and want to lose half of your money. What's the easiest way
to do it? The easiest way to do it, if you're a millionaire, is to call up
your accountant and say, "I would like to donate half of my money to Bill and
Melinda Gates foundation, please arrange this."

That's a strategy. You can write it down on a piece of paper and fax it to
your accountant with your signature on the bottom, after a few more signatures
it's done.

So, what is the difference between THIS strategy and a DIET strategy? Simple:
When you wrote that down to fax your your accountant (or booked a hotel room
by email, or booked an appointment with a repairperson, contractor, whatever,
basically anything like that) then the strategy you wrote down and faxed, in
that fax, had the effect that the person it addresses WILL OBEY YOUR COMMAND.
They will follow your strategy.

Whereas, if you decide "every morning 5 pushups" and write it down, even if
you fax it to yourself that does NOT mean that its recipient (you) will do 5
pushups the next morning.

In other words, every diet book on the planet thinks that you are the boss of
the person doing the dieting and exercising, and simply have to micromanage
what they do.

But you are NOT the boss of you. Let's recap.

Writing:

"Dear ---, After careful deliberation I have decided that I will immediately
be donating 1/2 of all of my wealth to the Bill and Melinda Gates foundation.
Please liquidate an appropriate portion of my investments in stocks, bonds,
and mutual funds (in equal measure) for me to to be able to donate half of my
net worth, and then prepare the donation for my signature. Yours truly,"

now it will start to happen, and another signature or two and it's done. (Even
if this was considerable work for the accountant!!!)

Now write down: "Starting tomorrow morning, as soon as you wake up please
ensure your first action is to do 5 pushups and 5 situps. For seven days do
so, then for the next week do 10 of each, the next week 15 of each, then 20,
and os on, until you reach 50 of each (after 10 weeks), which you should keep
doing indefinitely. Yours truly, yours truly."

Simple strategy, right? Only problem is, if you fax it to yourself, I can
almost guarantee you that the recipient of the fax will not do what you want.
Even if you sign it. Even if you really, really want you recipient to follow
through. They won't.

Every single diet book makes the SINGULAR mistake of thinking that its reader
is free to choose a strategy of consumption and of exercise. Not so: the
reader can agree with every word. Unlike agreeing with every word of
investment advice that a rich person can order an accountant to follow through
on, the reader of any diet book has no such power to order that a strategy (of
either diet or of exercise) be executed.

\- read about Tahiti, decide you want to see it, call your travel agent and
have them book a room in Tahiti, and a room will be booked in Tahiti.

\- read a fad diet, decide you want to see the results, and... no guarantee
you will have a chance to see them.

In sum, if you see what is wrong with the present offering, please email me
for collobaring on an interesting alternative.

~~~
Drbble
You aren't wrong, but you could cut 70% of the words from your post without
losing the point. Trim the fat.

~~~
its_so_on
Sorry, I've waited a day before this reply since I think the mods didn't like
that I seemed a bit like an infomercial. see sister post, you may also be
interested.

------
vsviridov
tl;dr - eat less

------
Pressenter
These articles are so amusing. As a regular cyclist eating too much has never
been a problem for me. If people really wanted to be thin they would get their
ass out on the bike trail with the rest of us ridiculously fit people instead
of sitting in front of the television. Since its pretty lonely out there most
of the time its clear what choice people are making and I don't feel one bit
sorry for you when you have to live with it. Fatty.

