Friday, February 22, 2013

Emotional Eating


First off, while a lot of the feedback from the Orthorexia series was quite positive (and here is a really thoughtful blog post offshoot from the series), I got some comments and emails accusing me of being silly and judgmental about people’s concern about their diets. So I do want to clarify one point: I care not one whit what you eat*. I do care about you as a human being, but I don’t judge whether you eat skittles for breakfast or you painstakingly raise and consume special pellets of moss species that flourish only on the carefully collected dung of endangered Himalayan goats. If any of those things makes you happy and productive and healthy and wonderful, I’m thrilled. My only concern was to suggest that some folks are trapped a bit by anxiety about what they eat, some to an extent that it negatively affects their lives and functioning. If you aren’t anxious about your Himalayan goat dung moss diet and you are happy and healthy, you do not have a problem. 
So let’s jump from the frying pan and right into the fire. “Emotional eating” is a soft phrase. There’s nothing to hold onto with it, no mineral deficiencies, no magnesium in receptors, no quick solution. It doesn’t hold the heaviness, wonder, despair and artistry of the human soul soaring in love, suffering in loss. There’s none of the poetry of nuzzling of a baby’s soft skin or hands caressing a loved one or the terror of violence in emotional eating. But I’ve sat with people in the midst of killing themselves with binging. I’ve sat with people who barely eat enough to survive and who can’t eat a meal without shame. Who are facing below the knee amputation for sores from diabetes but walk into clinic with a bag of candy. Emotional eating is an important thing to comprehend, but even the description of it brings along the dreaded spectre of “gluttony and sloth.” I don’t believe the entire Western human race was infected with a sudden onslaught of gluttony and sloth! But let’s look more at “emotional eating.” 
It’s just food. Food is life. Let food be your medicine…one of the reasons I like Dallas and Melissa Hartwig’s “It Starts With Food” so much is that they don’t begin with macronutrients, a long tale of a diet success story, or discussing the evils of different food toxins. No, the entire first section of the book is devoted to the psychology of food and eating, and one of the main criteria for an acceptable “Whole30” food is that it must promote a healthy psychological response. No weird cravings. No sweaty withdrawal dreams. Just eating for eating’s sake and enjoying the flavors, then letting it go and moving on to the next thing in life.
I’ve spent quite a bit of time on this blog discussing the parallels between addiction and binge eating. The book will have whole sections exploring that…but addiction is also a cold and measurable term. Use despite harm. Consuming more than intended. Spending a lot of time and resources finding and using. Using in secret. Sure, most people would agree that is a problem. 
But what about the plain old vanilla grazing and thoughtless eating while bored, or the friendship of a bowl of ice cream on a lonely Friday night? Grazing even though you don’t mean to at the holiday party. Not really a massive binge, no terrible secret, but over time these small overages seem to add up and have an unfair cost. So what does it mean to emotionally eat?
In the literature (1) “emotional eating” is equivalent to “comfort eating” or “stress eating.” Obviously, people who eat when stressed derive some sort of benefit from the eating, and for the most part, they are not eating celery sticks and steamed broccoli, or even a wholesome baked potato. When you are stressed or scared or bored what do you want to eat? Sugary snacks, cheesy bread, coffee, Doritos, or wine. Or sometimes the foods Mom used to make (which encode happy, secure memories, presumably).  “Comfort eating” is not clinically defined for happy situations, oddly enough. All the clinical scales refer to eating in response to stress.  However, there may well be sex differences in comfort eating, with men being more positively driven and craving familiar, savory foods, while women are more driven by negative emotions and crave sweets or wine. It shouldn’t surprise you that estimates of the incidence of emotional eating in the population are nebulous at best. Studies have used different questionnaires, different populations, different validities. Emotional eating does tend to happen more in women than in men, and more in adults than in children. Interestingly, in a general survey of the Dutch population taken 25 years apart, in 1983 23% of the population admitted to emotional eating. In 2009, 36% did so.
It is actually more common in these various studies for those under stress to report a suppressed appetite than a desire for comfort foods. Binge eaters are more likely to report cravings for food under stress, and non-binge eaters more likely to report decreased appetite under stress.
Emotional eating has long been used to try to define the cause of obesity in general, starting with Hilde Bruch, the psychiatrist who first wrote books on obesity and eating disorders as psychiatric phenomenon. Since obese individuals were seen more often in studies to eat when they were not hungry, or to have intake divorced from hunger, it seemed a logical conclusion that emotional factors were at play. Measures of dietary restraint (that is, the ability to turn down food even when hungry) are higher in those with high BMIs, and emotional eating (giving up dietary restraint) is seen much more often in people with higher levels of dietary restraint. As in restraint may beget emotional eating on the other side.  Of course, folks with higher BMIs are incentivized to attempt to turn down food, whereas many lucky folks with naturally low BMIs have never needed to exhibit much dietary restraint. It’s a messy business, trying to sort out natural food cues, hormonal dysregulation, and societal influence. But I do think it is a valuable exercise to determine how emotions cue us to want to eat, particularly unhealthy foods, even when we don’t need to.
In animal studies, there are certain protections against stress-induced eating, such as cutting out the adrenal glands (not recommended) or lack of an “energy dense” diet (lack of sucrose or high fat diet availability). In rats, activation of the HPA axis in the stress response is associated with more cravings for sweet foods than for fat. In humans, stress (such as exams or higher workload) has, not surprisingly, been associated in many different types of studies with cravings for sweets and higher energy-dense foods. Fast food consumption and chocolate increases during high stress weeks, fruit intake seems unaffected. Cortisol levels and urinary cortisol excretion are correlated with energy intake, and in women given solvable or unsolvable puzzles along with snacks in a controlled trial, those with the unsolvable puzzles ate more M&Ms and fewer grapes than those who were given solvable puzzles. In a study of women in San Diego, those with higher depression rating scores ate twice as much chocolate as those with normal depression rating scores.
The obvious question when looking at all this negative mood leading to emotional eating data is whether or not comfort eating actually improves mood. Not surprisingly, the data is mixed and the data collection confusing. Binging might actually improve mood because it results in a parasympathetic rebound of digestion, sleepiness, and relaxation. However, in an emotional binge eater, feelings of guilt and shame are liable to come to the forefront as well. 
Chocolate is the most commonly craved food during negative affect, and the sugar, caffeine, and theobromine could actually directly lift mood. Chocolate, eaten on an empty stomach with the high fat content, low protein content, and sugar content could result in an increase of tryptophan being shuttled into the brain, increasing serotonin levels. In rats, craving for chocolate can be shut off with opiate receptor blockers. And in female students, the main food that has been shown to alleviate pain and the main food craved by emotional eaters during a stressful task is chocolate chip cookies. Chocolate could reverse the sad feelings induced by watching a tear jerking film, but the effect was short-lived, only 3 minutes. (I think a fun job would be to dream up stress eating measurement studies). 
More evidence that food can improve mood is found in following people with seasonal affective disorder, who eat and crave more sweet foods during the winter. The cravings are decreased with light therapy.  Per capita sugar consumption is highly correlated with depression rates in countries (Why might that be???  PLEASE someone do a large study on fructose malabsorption and depression.)
Does comfort eating cause harm? Among studies of obese patients, generally less than half consider themselves comfort eaters, suggesting that it is an issue in a minority of people. In several studies (including the Dutch one mentioned earlier), emotional eating has increased with the prevalence of obesity, suggesting a connection.  Emotional eating is also strongly correlated to increased incidence of depression, sensitivity to stress, and impulsivity.
Genetic studies have pointed to issues with dopamine, serotonin, and all the usual suspects with respect to appetite and reward in the brain, but the pathway forward so far as treatment is far from clear. In some emotional eaters, an SSRI is helpful and decreases BMI. In others there is insidious weight gain. Wellbutrin, naltrexone, and topamax have all had some evidence for binge eating reduction. Naltrexone blocks opiate receptors and thus some reward pathways. Wellbutrin modulates the dopamine system (and thus affects the reward pathways). No one is really sure how topamax works but it does seem to blunt appetite and reduce binge eating, and also reduce that tricky problem that some have of night eating. These are not FDA approved uses of these sorts of medications, but there is nothing FDA approved for “emotional eating.” And for some people, literally killing themselves with binges despite major cardiovascular risk factors, or binging and purging constantly, the benefit/risk discussion changes with respect to using medication.
So far as non-pharmacological approaches to emotional eating, I’m aware of two major contenders. One is mindful eating (described in detail in the HBO documentary “Weight of the Nation.”) The other is “Food rehab.” Almost every diet from Atkins to South Beach to Whole30 or 21 Day Sugar Detox has a strict “buy-in” period that is a kind of food rehab, blocking access to trigger foods. I think different sorts of people will benefit from different strategies, and will discuss this further in another post.

*unless you are a murderous cannibal. Then I disapprove.

9 comments:

  1. Insidious weight gain? Where have I heard that before? Shall I add it to my MDA chart of progressive carb intake/creeping death imminence?

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  2. "“Emotional eating” is a soft phrase. There’s nothing to hold onto with it, no mineral deficiencies, no magnesium in receptors, no quick solution. It doesn’t hold the heaviness, wonder, despair and artistry of the human soul soaring in love, suffering in loss. There’s none of the poetry of nuzzling of a baby’s soft skin or hands caressing a loved one or the terror of violence in emotional eating. "

    Man, you can really spin a phrase, doc.

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  3. There are many great books based on the recounting of strong and destructive emotions. Is there a great novel of emotional eating?
    I can recommend The Debt To Desire by John Lanchester as a brilliant foodie novel, a cookery manual and travelogue interlarded subtly with dramatic recollection, very much in the erudite, self-absorbed style of Nabakov (does for recipe books what Pale Fire does for poetry, perhaps) but emotional eating... any recommendations?

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  4. Sorry, the correct title is The Debt to Pleasure. the narrator starts by saying his literary model is Brillat-Savarin. But you can't trust a lot of what he says, except the recipes, which are simple and excellent versions of classic dishes.

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    1. Good vegetarian orthorexia treatment in a short story - The Claxtons by Aldous Huxley (In the Brief Candles collection) which covers themes you addressed in the Orthorexia series. Starts before WW1 but nonetheless familiar territory.

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  5. First, thank you for this series of posts. I think it's a very important thing to talk about, and you're doing it rationally and non-judgmentally (as expected), which is rare and equally important.

    Second, re: It is actually more common in these various studies for those under stress to report a suppressed appetite than a desire for comfort foods.

    That's me exactly. I have heard so often that women "eat when stressed" that I've always thought I must be some strange aberration, because when I get stressed -- even when it's the mild stress of airplane travel -- my appetite completely shuts down. I was so stressed the last month of my PhD I lost about 15 pounds (that I didn't have to lose) because I ate almost nothing the entire month. It is reassuring to hear that suppression of appetite when stressed is not actually a shockingly rare thing.

    Third, I don't know how this fits in, but I was drastically underweight for most of my life -- between 100 and 110 lbs at 5'8" -- entirely because I had no appetite. Eating was a chore, something I did because it was necessary to stay alive, not because I had any desire to eat whatsoever. I literally did not feel hungry. About five years ago, in my early twenties, I was put on an antidepressant, and my whole world changed. All of a sudden, I knew what hunger was, and eating because enjoyable instead of unpleasant. I'm now 130 lb, putting me right in the middle of a "healthy" BMI. (Fortunately, I still exhibit no tendency to overeat, it's just given me a healthy appetite.) I was prescribed the antidepressant for insomnia and depression, which it has helped, but it's "side effect" of increasing appetite has been the most dramatic improvement in my quality of life. There is obviously some kind of link there between the brain chemistry of depression and the brain chemistry of eating.

    BTW, if anyone wonders -- and I used to get this a lot from people who struggled with being overweight -- there is nothing enjoyable at all with being 20 to 30 lbs underweight. It is not something to strive for. Being a healthy weight, not underweight, not overweight, is what allows you to live your life to the fullest.

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  6. "Theories that diseases are caused by mental states and cured by will power are always an index of how much is not understood about the physical terrain of a disease."

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