What Properties Make a Food "Addictive"?

Although the concept of food addiction remains controversial, there's no doubt that specific foods can provoke addiction-like behaviors in susceptible people.  Yet not all foods have this effect, suggesting that it's related to specific food properties.  A new study aims to identify the properties that make a food "addictive".

Introduction

Read more »

Is Refined Carbohydrate Addictive?

[Note: in previous versions, I mixed up "LGI" and "HGI" terms in a couple of spots.  These are now corrected.  Thanks to readers for pointing them out.]

Recently, a new study was published that triggered an avalanche of media reports suggesting that refined carbohydrate may be addictive:

Refined Carbs May Trigger Food Addiction
Refined Carbs May Trigger Food Addictions
Can You be Addicted to Carbs?
etc.

This makes for attention-grabbing headlines, but in fact the study had virtually nothing to do with food addiction.  The study made no attempt to measure addictive behavior related to refined carbohydrate or any other food, nor did it aim to do so.

So what did the study actually find, why is it being extrapolated to food addiction, and is this a reasonable extrapolation?  Answering these questions dredges up a number of interesting scientific points, some of which undermine popular notions of what determines eating behavior.

Read more »

The Neurobiology of the Obesity Epidemic

I recently read an interesting review paper by Dr. Edmund T. Rolls titled "Taste, olfactory and food texture reward processing in the brain and the control of appetite" that I'll discuss in this post (1).  Dr. Rolls is a prolific neuroscience researcher at Oxford who focuses on "the brain mechanisms of perception, memory, emotion and feeding, and thus of perceptual, memory, emotional and appetite disorders."  His website is here.

The first half of the paper is technical and discusses some of Dr. Rolls' findings on how specific brain areas process sensory and reward information, and how individual neurons can integrate multiple sensory signals during this process.  I recommend reading it if you have the background and interest, but I'm not going to cover it here.  The second half of the paper is an attempt to explain the obesity epidemic based on what he knows about the brain and other aspects of human biology.

Read more »

Food Variety, Calorie Intake, and Weight Gain

Let's kick off this post with a quote from a 2001 review paper (1):

Increased variety in the food supply may contribute to the development and maintenance of obesity.  Thirty-nine studies examining dietary variety, energy intake, and body composition are reviewed. Animal and human studies show that food consumption increases when there is more variety in a meal or diet and that greater dietary variety is associated with increased body weight and fat.

This may seem counterintuitive, since variety in the diet is generally seen as a good thing.  In some ways, it is a good thing, however in this post we'll see that it can have a downside.
Read more »

Book Review: Salt, Sugar, Fat

Michael Moss is a Pulitzer prize-winning journalist who has made a career writing about the US food system.  In his latest book, Salt, Sugar, Fat: How the Food Giants Hooked Us, he attempts to explain how the processed food industry has been so successful at increasing its control over US "stomach share".  Although the book doesn't focus on the obesity epidemic, the relevance is obvious.  Salt, Sugar, Fat is required reading for anyone who wants to understand why obesity is becoming more common in the US and throughout the world.

Read more »

Your Brain on Potato Chips

Or, more accurately, a rat's brain on potato chips.  Last week, PLoS One published a very interesting paper by Dr. Tobias Hoch and colleagues on what happens in a rat's brain when it is exposed to a highly palatable/rewarding food (1).  Rats, like humans, overconsume highly palatable foods even when they're sated on less palatable foods (2), and feeding rats a variety of palatable human junk foods is one of the most effective ways to fatten them (3).  Since the brain directs all behaviors, food consumption is an expression of brain activity patterns.  So what is the brain activity pattern that leads to the overconsumption of a highly palatable and rewarding food?

Read more »

Salt Sugar Fat

I'd just like to put in a quick word for a book that will be released tomorrow, titled Salt Sugar Fat: How the Food Giants Hooked Us, by Pulitzer prize-winning author Michael Moss.  This is along the same lines as Dr. David Kessler's book The End of Overeating, which explains how the food industry uses food reward, palatability, and food cues to maximize sales-- and as an unintended side effect, maximize our waistlines.   Judging by Moss's recent article in New York Times Magazine, which I highly recommend reading, the book will be excellent.  I've pre-ordered it.

Food Reward Friday

This week, Food Reward Friday is going to be a little bit different.  I've received a few e-mails from people who would like to see me write about some of the less obvious examples of food reward-- foods that are less extreme, but much more common, and that nevertheless promote overeating.  Let's face it, even though they're funny and they (sometimes) illustrate the principle, most people reading this blog don't eat banana splits very often, much less pizzas made out of hot dogs.

So this week's "winner" is something many of you have in your houses right now, and which was also the subject of an interesting recent study... potato chips!

Read more »

Food Reward Friday

This week's "winner"... the Banana Split!

Read more »

Food Reward Friday

This week's lucky "winner"... an unnamed hot dog-laden Pizza Hut monstrosity with tempura shrimp and mayonnaise!

Read more »

Why Do We Eat? A Neurobiological Perspective. Part VIII

In the (probably) last post of this series, I'll take the pieces that I've gradually outlined in previous posts, and put them together into a big-picture, common-sense framework for thinking about human eating behavior, and why we eat more today than ever before.

Why is Eating Behavior Regulated?

Let's start at the most fundamental level.  To be competitive in a natural environment, organisms must find rational ways of interacting with their surroundings to promote survival and reproduction.  One of the most important elements of survival is the acquisition of energy and chemical building blocks, either by photosynthesis, or (in the case of animals) eating other organisms.  This imperative drove the evolution of rational food seeking behaviors long before the emergence of humans, mammals, reptiles, amphibians, fish, worms, and even eukaryotes (organisms with nuclei).

Read more »