First off I wanted to link to my latest podcast; this one is with Michael Ostrolenk at the Voices For Hope Podcast. I had a great time talking to Michael, and we managed to squeeze a lot of me talking in the lean 17 minute interview. It's funny - since in my line of work I typically do a lot of the listening, sometimes when people ask me questions I can really get going…
Evolutionary Psychiatry at Voices For Hope
And now onto the gentlemanly duel of mild-mannered, gorgeously-referenced, thoughtful posts between Stephan Guyenet and the Jaminets at Perfect Health Diet - if "food reward" is a dominant factor in obesity, should we be eating a new brand of "bland" paleo? Is obesity regulation in the brain, the liver, the adipose tissue, or the gut?
I will approach the question(s) a bit from the hip and from a clinical perspective, focusing on the far end of the food reward and obesity spectrum (which certainly will not describe all those who are obese) - the binge eaters. For a little (referenced) perspective on the neurobiology of binge eating, read my posts here and here.
So… what do I like about the "food reward" theory of obesity - (in the briefest of nutshells, the idea that constant exposure to overly palatable food overwhelms our natural feedback mechanisms and causes us to overeat)? This theory is brain-centric, and I'm a brain-centric sort of person. It is similar to addiction (and involves many of the same neurotransmitters and brain areas) - an addiction is also tough (or impossible) to shake, involves inflammation as part of the brain pathology, and seems to afflict people along genetic lines. Some folks can shoot up a bit of heroin, for example, and never feel the urge again, while others get a prescription for percocet after a work-league softball injury and are off to the races, snorting oxycontin and spending $300 bucks a day. The numbers for addiction and dieting are comparable - quitting smoking cold turkey, for example, has somewhere around a 5-12% success rate long term. Any and all diets seem to be similar - 95% of people regain the weight within 5 years.
The treatment for addiction is to abstain, one way or another. A certain percentage of alcoholics can, one day, go back to moderate drinking, but some will never be able to touch alcohol again or end up back in the sober house without driver's license, job, or family - even 15 or 20 years into sobriety. If "food reward" is a problem of overly palatable food, then the solution seems to be to go bland. A compelling argument, really, and seems nicely in line with an Eastern philosophy of striving towards the state of wanting nothing. Kessler in The End of Overeating: Taking Control of the Insatiable American Appetite calls the sugar/fat/salt combo in industrial, processed, and restaurant food "hyperpalatable" - and for him the solution is "food rehab" - abstaining and developing a sense of disgust about that sort of food.
The Jaminets are concerned that our brains have a food reward system for a reason - succulent lovely amazing fruit and bone marrow and drippy yummity steak are highly nutritious and good for us. Should we be deliberately trying to go bland in the name of dropping pounds?
Here's where my clinical brain and experience with patients gets involved. I've talked to a lot of people struggling with addiction over the years, and a lot of people struggling with binge eating, bulimia, or some variation in between. And, I have to say, the struggles and cravings and relapses and descriptions people relate to me about their bingeing have very similar flavors, whether you are bingeing on Little Debbies, Taco Bell, or Jack Daniels.
There's a love affair with the food or drug - thinking about it, craving it, desiring it, then a shift into automaton binge so that the lead-up is typically far more pleasurable than the actual event. And always along for the ride comes some sort of awfulness, even putting aside the guilt and recrimination. Often when people shoot up heroin for the first time, they vomit. Cigarette smoke - it's nasty, you cough, you smell - it's unpleasant. Cocaine stings the nose and leads to sudden euphoria followed by a much longer period of irritability and depression. And, for the most part, the food that humans typically binge on is.. well… kinda nasty (seriously, look at that bag of creamsicle oreos in that link to Melissa's blog!). It's too sweet, has crappy texture, smells of chemicals - it's Taco Bell meat "product" or rancid oily Pringles or gut-bursting amounts of slippery pasta. For most people (including myself), those healthy, magnesium and copper containing richly flavored low in O6 bars of 85% dark chocolate (intense, addicting chocolate) can be lovingly divided and savored over a week or two - but if I buy the toffee version (34% cacao, milk chocolate) I have to divide it with my kids or I will easily gobble down the whole bar and end up with a sickly feeling and a tummy ache.
So I don't know that straight-up palatability is the end all be all - though Stephan's experiments in treating obesity with low-reward food that he references are fascinating, and he might well prove me wrong. I think the similarity between the hyperpalatable industrial food and the hard drugs is that they are all (somewhat metaphorically) poisons, but we take the dose anyway, and need bigger and bigger amounts.
So far as obesity - and now I'm talking about the general problem, not just the subsection of serious binge eaters and subclinical versions of that - I think that in some people, the problem is in genetic vulnerabilities in the reward system in the brain. In others, it's a methylation problem in the liver. In others, and issue with gut flora. Or combinations of all of the above, and many other things I'm certainly not an expert in. All the pieces are related, all could affect the ultimate downstream leptin areas in our noggins. So perhaps some folks will need to go bland, or at least do so for a while as the inflammation goes down. Others can dive into the bone marrow salad dressing, eat nectarines dripping with juice, and use the pepper with gusto.
These are my speculations. Take them as you will.