Food addiction's a hot topic these days.
Proponents posit that food addiction is a real phenomenon that leads people to almost irresistibly eat.
Opponents believe that it doesn't exist, and it's just a means with which people justify their difficulties with food.
What if they're both right?
A recent study's got me thinking. Now be forewarned, it's an animal study and therefore not necessarily attributable to human beings, but nonetheless....
The study looked at minipigs (which as evidenced by the photo up above are almost unbearably cute), where brain activation of seven diet-induced obese minipigs, were compared to brain activation of nine lean minipigs following an overnight fast.
The findings were striking. The obese minipigs had a great deal more activation of their prefrontal cortices compared to the lean minipigs, where the prefrontal cortex has been shown to be involved in addictive behaviour in humans.
They also found decreased activation in the reward centres of the obese minipigs (the ventral tegmental area and the nucleus accumbens), which suggests the possibility that food "addiction" might in fact cause some sort of habituation in these brain regions which in turn would lead to individuals to require larger hits of food, to get the same brain-based reward.
But here's the thing. The minipigs, with clearly different brain chemistries, didn't self select for being obese, they were chosen to be fed more. At first they ate fairly normally, despite having ready access to food all day long (as opposed to their brethren), but then over time, and living in their all-you-can eat buffet hutches, they started to eat more. By the end of the experiment, they weighed nearly double the weight of their peers. And by the end of their experiments, their brains had changed.
This may suggest that while food addiction indeed has neurophysiologic foundations, that it's the chicken and not the egg. Meaning that these pigs weren't born addicted to food, they developed food addictions after living in what might be described as a toxic food environment.
That's exciting to me, in that if we can help people regain control over their food environments, if we can help people ease into more satiating patterns of eating, maybe we can rewire their brains, and in so doing, short-circuit these unnaturally derived neural pathways and responses.
And ultimately, I think we can. Why? Because I see it in my offices on a very regular basis (though not every time mind you, there are some folks who seem to truly struggle with these behaviours regardless of the tweaks we try).
Which is why I think both proponents and opponents are right, where food addiction has a real physiological foundation, but where there is certainly a pattern of eating that may, in some cases, predispose people to heightened neurophysiological drives to eat.
Of course when you think about it, none of this is particularly surprising. After all, couldn't the same can be said about pretty much every addiction?
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Val-Laillet D, Layec S, Guérin S, Meurice P, & Malbert CH (2011). Changes in brain activity after a diet-induced obesity. Obesity (Silver Spring, Md.), 19 (4), 749-56 PMID: 21212769
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Very interesting blog post and link. You must have some access to more information than in that reference though because I don't see where they discuss the fattening of the pigs over time through free feeding. Can you provide that reference?
ReplyDeleteI'd also have questions as to what they were feeding the pigs to get them to eat to the point of becoming obese. And if that could have caused the addiction along with the obesity. In other words, is there something in the food altering the brain chemistry that could be causing both the food addiction and as a result the obesity. The cause and effect is not necessarily clear.
You mention the 'toxic food environment'. Do you believe it is toxic simply because of the unlimited amount of food available to these pigs or because of the quality of food or both?
Hi LCL,
ReplyDeleteThe feeding protocol's in the methodology.
Toxic food environment wise - great question.
I'm no expert in minipigs so can't comment on the healthfulness of the chow they were fed.
Ultimately though, and as I concluded, people aren't born with addictions, they develop them, and whether or not these pigs reflect pathways that are shared by humans or not, I'd wager that food addiction is something that develops as well, and like other addictions, is likely beatable by means of modifying behaviour.
I would have thought this fairly obvious? While perhaps, a child born of someone with an addiction may be predisposed to also develop it, addictions are created through habits.
ReplyDeleteAs for food environments, if you have a Mars bar or an apple at school...yet at home you only ever have Mars bars...it is 99% likely that you will also choose a Mars bar to snack on at school. One has to wean themselves off sugar and salt and only once you have are you able to actually TASTE the sweet and the salty again and realize just how sweet or how salty something was.
It has been shown in studies that portion size and our perception of being full are related. If you have an endless bowl of soup versus a once filled bowl of soup, you are more likely to continue eating and missing your bodies ques that you are full, especially if 'unlimited' food is common in your life. This is a major difference between North American food culture and Japanese or French. They have different ways of knowing when to stop eating whether it is when 80% full or just by limiting portion size, yet improving food quality.
So here's the problem with the behavioral approach. If, for example, we free fed these pigs with their natural chow (whatever that is) mixed with amphetamines. Assuming they had a similar addictive response to the drug as humans, they would be come addicted and eat more than they need to support their life and they would become obese.
ReplyDeleteYou could attempt a behavioral approach by forcing them to eat less of the amphetamine mixed chow and they would probably lose weight but the addiction would not go away. They would be fighting the urge to eat more, or unable to follow that urge because of limited food supply.
On the other hand, you could remove the amphetamine from the chow and two scenarios are possible. They would eat less because they are not getting the buzz they used to and either maintain or lose weight. OR because the behavior of eating more than they need has been re-enforced in the past by the buzz of the drug, they would continue to eat more than they need.
The point is, IF it is something toxic in the food that is causing the food addiction and subsequently the obesity, then just going at a behavioral approach may cause improvement but at the cost of fighting urges to eat more. Removing the toxin (the Mars bar in Reuby's comment for example) may result in behavior modification on it's own to some extent as the addictive element is gone. It may require behavioral changes after this point but they should be easier as the addictive toxin is no longer present.
I do not disagree with behavioral approaches (eat less and exercise) but ONLY in combination with looking at what in the diet is causing the problem in the first place. Obviously from my pseudonym, I believe that it is carbohydrates (especially refined grains and sugars) that should be removed as being addictive (amongst other things).
Now, I will add that I am making an assumption that the overeating is the result of something other than just the free feeding of the pigs. I may be wrong but I don't think that is any less valid an assumption then that the free feeding of the pigs caused the pigs to eat enough to become obese. The cause and effect should really be determined though before coming up with a treatment though, shouldn't it?
A quick comment on Reuby's comment. Addiction is not always behavioral. As with drugs, alcohol, etc, it is chemical as well. If it is chemical, a behavioral approach may work but in the case of drugs and alcohol for example, this approach is always accompanied by a removal of the addictive substance. With food addiction, often behavioral approaches do not remove specific foods that cause the addictive behavior. Imagine trying to treat an alcoholic by having them reduce the amount they drink rather than telling them not to.
I have met (and lived with) two people that I consider food addicted. We were all patients in a bariatric program in a nursing home/rehab center. I have no idea how they became addicts but I have no doubt, based on my interactions with them that they were indeed addicted to food. Unlike the rest of us chunkies in the program, these two would have been better off in a substance abuse type program designed for addictive personalties. They needed more supervision and more behavioral help then the program we were in could provide.
ReplyDeleteI would agree that food addiction is likely caused by overeating. Having been an addict of various things in my life, I have felt that urges to eat have definately felt addictive, though not so much these days. Now I can take it or leave it, and maybe it's because most of the "addictive" foods aren't a huge part of my regular diet. I may still overeat them at times, just because they taste so good, and I have them so rarely, but I would no longer consider that anything resembling addiction.
ReplyDeleteI congratulate you on getting past your addiction. I would not however that the statement "food addiction is likely caused by overeating" is odd. Is it cause effect or is there something causing the addiction that is resulting in over eating?
ReplyDeleteAfter all, we don't really say that alcohol addiction is caused by over drinking alcohol and that if we just drank less we would kick the addiction.
Some interesting comments.
ReplyDeleteI think looking at some of the ways in which we define addiction can be helpful. Primacy of the behaviour, tolerance to the effects, escalating the dose to achieve the required effect, recognised withdrawal symptoms etc. Does increased food consumption share these characteristics?
If we're talking changes to the brains reward systems through eating, then quite a lot of research has gone into looking at the dopamine system. I particularly like the way regular eating keeps the dopamine system 'topped up', theoretically reducing craving driven eating.
found it!
ReplyDeleteThanks for the link!
ReplyDelete"Topping people up" is exactly our strategy here, augmented with ensuring protein at every meal and snack and making sure that meals and snacks don't fall below a minimum number of calories.
I love your blog and have read it many times. What great information!
ReplyDeleteBased upon my own experience, food used to beg me all day long to take another "hit." The only thing to make it stop was to take ALL the refined food out of my diet for about 3 weeks until the cravings completely stopped. (And yes, I was a light-headed mess during those 3 weeks of rehab.) After those weeks of agony, I was able to walk straight by cookies and other treats.
Several months later, I don't have cravings at all anymore, but that is because I quit eating all the refined foods. (I try to eat only 300 cal/day of refined foods). I get no more "zing" in my brain from my food, but it's even a bigger pleasure to feel in control of my food.
Marion@affectionforfitness.blogspot.com
Great post.
ReplyDeleteThis is something that I often wonder about due to what I used to beleive was my "addictive" nature (i.e. addiction to smoking, then addiction to drinking after quitting smoking, then addiction to food after quitting smoking). My need to replce one method of instant gratification with another.
However, when I was growing up I never had any "addictions". I beleive half the problem these days is the over availability of things and too much choice.
I go through periods of being extrememly healthy and then periods of huge binges that go on for weeks or months even. What usually happens is I'll think "ooh, I feel like eating some chocolate" but there is none in the house so I go to the supermarket. When I get there I think "Oh, do I want chocolate or ice cream?" and then I don't want to miss out so I get both...then I wander past the potato chips and I think "hmmm, maybe I want chips?". See where this is heading? Yep, to the checkout with a basket full of goodies!
We are spoilt by choice and that makes some of us want a bit of everything in fear of "missing out". Some of us have trouble stopping at "just a bit" and end up eating until it's all gone (I seem to have missed the common sense gene that tells me "you feel sick so stop eating!". Then we do it again the following day when we get the same cravings, it becomes habitual and the habit is hard to break. For some people it does become an addiction but you are right, we are not born this way.
Right now I'm working on "the chocolate will still be there next week - the world won't run out overnight and leave me regretting not chowing down on this family sized block RIGHT NOW!!"
:)