The Case for the Food Reward Hypothesis of Obesity, Part II

In this post, I'll explore whether or not the scientific evidence is consistent with the predictions of the food reward hypothesis, as outlined in the last post.

Before diving in, I'd like to address the critique that the food reward concept is a tautology or relies on circular reasoning (or is not testable/falsifiable).  This critique has no logical basis.  The reward and palatability value of a food is not defined by its effect on energy intake or body fatness.  In the research setting, food reward is measured by the ability of food or food-related stimuli to reinforce or motivate behavior (e.g., 1).  In humans, palatability is measured by having a person taste a food and rate its pleasantness in a standardized, quantifiable manner, or sometimes by looking at brain activity by fMRI or related techniques (2).  In rodents, it is measured by observing stereotyped facial responses to palatable and unpalatable foods, which are similar to those seen in human infants.  It is not a tautology or circular reasoning to say that the reinforcing value or pleasantness of food influences food intake and body fatness. These are quantifiable concepts and as I will explain, their relationship with food intake and body fatness can be, and already has been, tested in a controlled manner. 

1.   Increasing the reward/palatability value of the diet should cause fat gain in animals and humans

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The Last Self Portrait

I usually take photographs during the day.  I was challenged to come up with something at night.  However, I didn't want the usual street scene with lights, neon, and car headlights.

A friend of mine likes to play a game inspired by the tv show, "I shouldn't be alive."  Or as I like to call it, "I should be dead."  This game is to choose one of the most extreme weather situations to see which one you would rather try to survive in.  The choices are (you are all alone with nothing in these situations) in the middle of the desert, in snow, in the middle of the ocean or the rainforest.  We debate on which would be the least painful and perhaps the most "survivorable."  I chose the rainforest and maybe the desert second.  What would you choose?

Anyway, back to the assignment.  I struggled on what to photograph until I passed by some chopped up pieces of wood in a small industrial area.  The first thought that came to my mind is the scene in the movie Fargo where a person gets fed to the wood chipper.  What if I drove by and saw an arm or leg mixed in with the pile of wood?  Well, why not recreate what was already on my mind?

So I did.  After the wood pile, I was excited to do more self portraits of scenes where you might see legs in areas where you least expect.  Perhaps these are murder scenes as viewed by people passing by or perhaps it's suicide and the camera documents the photographer's last self portrait.  Either way, its what you interpret in your head that makes up the story.

So, this might veer from my normal "style" but a welcome one in my mind.  It's a piece of my inside being reflected in a photograph.  The "last self portraits" were taken in order of the wood, wood chipper, by the telephone pole, and hung from the stairs.  As soon as I began, I couldn't stop thinking of more scenes.

Maybe these scenarios should be included in the "I shouldn't be alive" game.  Well, I suppose these photographs are from the "I didn't survive" program.  Either way, it was fun to do.  As I showed these images to my class, one student shouted out, "you're sick!" That was the best compliment I could have received.  I think he's right.

The Case for the Food Reward Hypothesis of Obesity, Part I

Introduction

When you want to investigate something using the scientific method, first you create a model that you hope describes a natural phenomenon-- this is called a hypothesis.  Then you go about testing that model against reality, under controlled conditions, to see if it has any predictive power.  There is rarely a single experiment, or single study, that can demonstrate that a hypothesis is correct.  Most important hypotheses require many mutually buttressing lines of evidence from multiple research groups before they're widely accepted.  Although it's not necessary, understanding the mechanism by which an effect occurs, and having that mechanism be consistent with the hypothesis, adds substantially to the case.

With that in mind, this post will go into greater detail on the evidence supporting food reward and palatability as major factors in the regulation of food intake and body fatness.  There is a large amount of supportive evidence at this point, which is rapidly expanding due to the efforts of many brilliant researchers, however for the sake of clarity and brevity, so far I've only given a "tip of the iceberg" view of it.  But there are two types of people who want more detail: (1) the skeptics, and (2) scientifically inclined people who want mechanism.  This post is for them.  It will get technical at times, as there is no other way to convey the material effectively.

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Art Inspired By Art

This past week I was asked to come up with a photograph inspired by another painting or photograph. My mind instantly went to one of my favorite images of all time, featuring John Lennon and Yoko Ono taken by Annie Leibovitz.  I am currently reading her book, "at work" in where she describes how this photograph came about.  Sometimes, the best shots you take are the ones where you are not in complete control.  You will have to read the book to learn why.  Unfortunately, this was one of the last photographs of John Lennon before he was shot the next day.

I love it when my friends are up to participate in my crazy requests.  I asked Jamie and Traci if they wouldn't mind recreating this photograph, but with a modern spin.  I didn't expect them to jump on board right away but they both agreed and thought it would be fun.  It was.

I came over with a large ladder, sheet and my camera.  We moved all of the furniture out of the way to place the sheet on the ground and then they put their comforter over the sheet.  I have a sliver of the couch showing and instead of jeans thrown over, their dog Ollie decided that the blanket looked like a nice place to lay down so he curled up next to them.  In this photo on the right, you can see the ladder with my foot and ollie's tail on the bottom of the sheet to give you an idea of what the scene looked like.

This photograph at the top is my favorite of the bunch.  It shows the love between these two.  A big thank you to two of my dearest friends for playing along.

Humans on a Cafeteria Diet

In the 1970s, as the modern obesity epidemic was just getting started, investigators were searching for new animal models of diet-induced obesity.  They tried all sorts of things, from sugar to various types of fats, but none of them caused obesity as rapidly and reproducibly as desired*.  1976, Anthony Sclafani tried something new, and disarmingly simple, which he called the "supermarket diet": he gave his rats access to a variety of palatable human foods, in addition to standard rodent chow.  They immediately ignored the chow, instead gorging on the palatable food and rapidly becoming obese (1).  Later renamed the "cafeteria diet", it remains the most rapid and effective way of producing dietary obesity and metabolic syndrome in rodents using solid food (2).

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Bringing The Past And Present Together In A Photograph

This week I am challenged to photograph my family in a unique way.  The timing of this project couldn't be more perfect.  As I blogged about it earlier, I am going through all of the boxes in my garage to either donate or sell.  This also means going through boxes and boxes of old photographs.  Many of these photos I haven't seen since I packed them away...whenever that was.

I read an entry on the Lenscratch blog about another site called, Dear Photograph.  This site posts photographs of photographs taken in the past into the present.  I loved the idea and decided to go through the box of photographs I collected to see if I had any from my childhood home taken outside.  I sorted through what I had and found a few taken in the front of the house and in the backyard.  I decided to take a trip to my childhood home to see if I could line up the photographs I had.

I haven't been to this house in over twenty years.  Even though it's only thirty minutes from where I live today, there hasn't been a reason to be in that area.  As I drove near, my instincts took over and directed me to my old home.  Needless to say, it was quite the experience.  Everything seemed so big as a child.  The neighborhood was the same but different at the same time.  I must have been driving about 10MPH in the neighborhood recalling experiences as a child as I approached the house.  I parked, gathered some photos and knocked on the door, not knowing what to expect.

A soft voice behind the door asked, "who is it? who's there?" What do you say to that?  I just said, "hi, I used to live here." She opened the door slowly to see who I was and what I wanted.  I extended the photos and said that I used to live there and wanted permission to take photographs around the house.  I don't think she really understood what I was trying to do but once she saw photos of her home and what it looked like in the 70's and early 80's she smiled and greeted me.  She wanted to see everything I had.  I showed her the photos, identifying myself, neighbors, my mom, grandparents and told her what it was like living there as a child.  She took me out to the backyard to show me what it looked like. I haven't seen that backyard since I was 14.  My father built a koi pond that is still there today.  She said that birds would eat all of the big fish so it's filled with smaller fish.  My dad also loved to take care of his bonsai and all of the plants on the property.  She said that she loves the flowers in the front and loves the koi pond.  She told me to tell him thank you.  He has since passed, but it was sweet to hear.

She saw a photograph of my mother standing next to the olive tree in the front and kept looking at it saying how beautiful my mother is.  I asked her if I could take he photograph and she said yes.  As I snapped it, I noticed her standing in the same way as my mother stood, as well as wearing stripes and jeans (see above).  We chatted for a long time and she even moved her car out of the driveway so I could take photographs and she also let me walk in the backyard to take more pictures.  She even came out with a bag of apples for me to take home.  I am very fortunate to have had this experience.  I will remember it forever.

Letting go of my things gave me much more than I expected.  I am grateful for the fifteen years I had in this home and for the experience I had yesterday.  Even though my father and grandparents are not longer with me physically, I feel them coming back to life through these photographs.  Below are a few I found and recreated.

How did I do it?  There really isn't a trick but just try to line up the photograph with the scene.  It's not as easy as it looks, especially if you are the person holding it and shooting it.  They aren't all perfect, but as perfect as I could get it. These are all straight out of the camera taken with my iphone and point and click.  I would highly recommend this experience to everyone.

One thing I know for sure...life goes by too fast.  Not to get all preachy on you or anything, but try to enjoy all of the moments you have now with your loved ones.  Listen to what your parents and grandparents say, take photographs, appreciate what you have and don't obsess about the things you don't have.

Me and my grandmother, "Mama Lois" in the backyard

With all of the kids on the block on our first day of school

All of us on our way to school

Being silly in front of the camera

Leaving on our family road trip.  That's my mother, me, my brother, grandmother "Mama Lois", and grandfather "Big John."  My dad took the photo.  Yes, we all got in that car and drove from Los Angeles to Vancover, B.C.

The backyard, then and now

My brother and I

My close neighbors, Carrie, Sandy and Chris the first day of school.

Riding a pony on the front lawn.  A guy with a pony would walk around the neighborhood asking if you wanted to take a photograph on it.

Me with my really sweet haircut in my extra cool swim sweats

My mom, haming it up in her satin pants

Me holding our family cat, colors

First day of school (seems like the only time we took photographs in the front)

And finally, on my big wheel.  I loved this thing...jumped on it right when I got home from school every day.

Primal Docs

Chris Armstrong, creator of the website Celiac Handbook, has designed a new non-commercial website called Primal Docs to help people connect with ancestral health-oriented physicians.  It's currently fairly small, but as more physicians join, it will become more useful.  If you are a patient looking for such a physician in your area, or an ancestral health-oriented physician looking for more exposure, it's worth having a look at his site:

Primal Docs

Update 9/22: apparently there is already another website that serves a similar purpose and has many more physicians enrolled: Paleo Physicians Network.