Although records of numerous food-related human-animal dilemmas now fill my files, four situations that occurred relatively early in my veterinary medical career remain fixed in my mind because of what they taught me about the connection between food and human and animal emotions. The first involved an overweight dachshund with pancreatic problems that responded well to medical and dietary changes. Even so, periodically the dog would experience sudden bouts of incapacitating pain. And always the cause was the same. Even knowing how it would affect her cherished pet, the owner would succumbed to the dog’s pleading looks and perfect execution of every trick or command response he ever learned sans command. And she rewarded him with ice cream, chips, or whatever treat she happened to be eating herself at that time. The owner offered these deadly foods and the dog accepted them with both knowing the consequences.
Because neither owner nor dog was stupid, I wondered what compelled the two of them to display such destructive behavior. What possible emotional benefit gained from offering or eating that food could exceed its devastating emotional, physiological, and (for the owner) financial cost?
Score one point for emotions and zip for logic.
In the second incident, another very intelligent client and animal (an obese black Lab) co-created a food-based mutual adoration society. Like two old pals who regularly do lunch to affirm their relationship and in the process eat rich deserts they wouldn’t otherwise, this human-canine duo similarly injudiciously over-consumed. However in their case, they did it 3 times a day plus a bedtime snack every day, week after week, month after month. Back then I repeated the standard “fewer calories, more exercise” mantra that most veterinarians still repeat today, specifically mentioning that the shared peanut butter toast, heaping bowl of ice cream, and mac’ and cheese had to go. But even though tears trickled down his cheeks, my client made it clear that no amount of guilt-mongering on my part was going to work. “No,” he said. “I won’t do it. I can’t do it. It would kill us both.”
Score: Emotions 2, Logic 0
Then there were the weekend food-bingers who shared this activity with their pets. They would call late Sunday night or early Monday morning because their animals were throwing up. Was it something serious or merely a case of mild dietary indiscretion? Because they also were co-creators in the animals’ medical ailment, they didn’t want to go to work and leave the animals if their pets needed more immediate medical attention. Sometimes the calls would repeat, but most binge-food suppliers learned to recognize the signs and how to treat them at home. Note that they didn’t learn not to repeat the food-binging with their pets. They merely learned how to treat its effects themselves.
Score: Emotions 3, Logic 0
The forth incident sealed my determination to write my first book, The Weekend Dog. In addition to the Monday Morning Barfers (and Limpers, but that’s a different story), I noticed an uptick in the number of calls or appointments involving dogs with GI upsets mid-week. Being one of those possibly annoying people who want to know why something happens, it didn’t take long to determine the factors that combined to create this phenomenon. For one thing, all of these dogs attended the same training class the evening before, a class taught by one of the few area trainers who preferred to use the punishment option offered in behaviorism’s limited reward-or-punishment repertoire. For another, all these animals and their owners lived in the same part of town. Third, simultaneously the general public increasingly was being exposed to a blitz of food-equals-love advertising which made food seem like the very best reward one could possibly offer. The final factor took this particular food-related interaction beyond its tipping point: between the recreational center where the training classes were held and where these folks and their dogs lived stood the town’s first fast-food restaurant, a shiny new, highly advertised, easily accessible McDonald’s with its convenient drive-through window.
Need I say more? To owners distressed from watching their dogs jerked around or yelled at, those golden arches loomed with all the allure of El Dorado. They ordered burgers, fries, and shakes that they naturally shared with the canine pals who had endured this ordeal with them, as well as to relieve their own guilt for putting the dogs through that. But the dogs normally didn’t eat that kind of food, let alone under those highly emotionally-charged conditions. Their already emotionally stressed digestive tracts rebelled and responded with vomiting or diarrhea, and sometimes both.
Final score: 4-0, emotion wins.
As a naïve young practitioner I couldn’t understand how intelligent people who said they loved their animals could continue to engage in feeding practices that undermined their animal’s health in spite of the fact that they knew better. But eventually experience taught me that trying to impose a negative emotion like guilt on this process only would make the situation worse. What I didn’t understand was why.
Later when I started following articles about the placebo effect, then read about those matched fMRIs in empathic clinicians and patients (see last month’s commentary) I got an inkling of why co-created emotion-based food-related effects could be so potent. Because of this, when I received Franklin McMillan’s article “Stress-induced and emotional eating in animals: A review of the experimental evidence and implications for companion animal obesity” in the Journal of Veterinary Behavior, I couldn’t wait to read it.
In this article, McMillan does an excellent job of overviewing most of the causes of overeating addressed in the human and veterinary literature. Of the three causes—hunger, food restraint/restriction, and disinhibition—research indicates that disinhibition is strongly associated with weight gain and obesity in humans.
Disinhibition itself takes different forms. Habitual disinhibition refers to weight gain that results from exposure to readily available, palatable foods. McMillan points out that although most of the veterinary literature refers to caregiver overfeeding, i.e. habitual disinhibition, as the primary cause of obesity, this ignores the fact that not all animals overeat when provided with an abundant food supply as all those optimum-weight dogs and cats fed free-choice prove.
Individuals with situational disinhibition more likely overindulge under certain social circumstances, such as parties, sporting events, movies, etc. Although once again companion animal studies are lacking, I readily can recall animals whose owners commented on how the presence of another animal caused their otherwise picky-eaters to clean their bowls. Similarly there’s no shortage of animals who refuse to eat or eat only a minimal amount in their owners’ absence. Sometimes that person must even perform a specific mealtime ritual before the animal will eat.
Once again and as often happens in behavior, the opposite response may occur: some animals will eat more or in a more leisurely, less stressed manner if certain animals or people aren’t around during their mealtimes. Similarly many of the dogs I see with serious behavioral issues will obey commands flawlessly for food rewards in a secure physical and mental environment, but completely ignore that same command and reward in more stressful circumstances. Because those “other circumstances—such as when the dog spies the meter reader or the neighbor’s Chihuahua—are the ones in which obedience really matters, those who have no other teaching options often are reduced to trying more or “higher value” foods and even punishment. They don’t realize that the dog’s response makes sense because establishing and/or protecting the territory takes precedence of eating and drinking… But not always as we shall see. Suffice it to say that situational disinhibition may overlap with emotional disinhibition, the third form disinhibition may take.
Those experiencing emotional disinhibitiontend to overeat for emotional reasons, but the line between emotional- and stress-related eating is fuzzy at best. This occurs because stressed individuals typically display enhanced emotional states compared to those not stressed under those same circumstances. Human and laboratory animal research reveals that the elevated levels of glucocorticoids associated with stress trigger food consumption as well as emotional processing. Consequently those studying human overeating and obesity now accept that eating, and especially overeating, provides a mechanism that enables people to alleviate or cope with stress and negative emotions. In these situations, eating triggers the release of opinoids (substances with effects similar to that of opium) and as such serves as a form of self-medication.
Putting these two physiological components together, we have stress-related changes spiking the desire for food in some individuals, and eating calming that response via the release of opinoids. Because of the relationship between synthetic opinoids and addiction, it seems reasonable to suggest that failure to address the underlying stress or negative emotions associated with over-eating won’t resolve the problem no matter how many dietary and exercise changes are used.
And speaking of exercise, its addition to the decreased-calorie approach to weight-reduction also challenges the notion that weight-reduction possesses no emotional component in animals. One study that offered tantalizing clues to the role emotion may play in the exercise-weight puzzle takes us all way back to research conducted in 1963 by D. Premack and A.J.Premack. The Premacks discovered that rats with access to an exercise wheel significantly reduced their food intake, but significantly increased their food consumption when the wheel was removed. The rats didn’t eat more when the wheel was available to replace the calories lost during exercise; nor did they eat less when the removal of the wheel eliminated the need for so much food. On the contrary they did exactly the opposite. This suggests that the exercise benefited the rats in some way that exceeded the benefits of food consumption. McMillan notes that this is what one would expect if the exercise provided emotional benefits such as relief from stress or negative emotions.
Other conclusions from human and laboratory animal studies of value when considering a comprehensive approach to the problem of overweight and obesity in companion animals include:
- In human subjects, eating doesn’t seem to reduce distress or increase psychological comfort in the long run. A friend who still struggles with her weight after multiple cycles through the increased-exercise-decreased-food-intake approach refers to this as “Trying to fill the Big Empty.” This is understandable given the results of studies of emotional eating: the less food available to soothe the emotions, the greater the desire for food.
- Although stressed individuals prefer certain foods for comfort, they’ll eat more of what’s available if these are not. This includes dogs and cats who will overeat when fed nothing but commercial pet foods, many of which are nutrient dense. And although McMillan notes that, unlike humans, dogs and cats are unable to choose their preferred foods to alleviate emotional stress, I disagree. It seems reasonable to me that a lot of those counter-surfers and trash-can scroungers seeking leftovers, to say nothing of those who eat an amazing array of nonfood items carrying the owners’ scent could fall into this category.
- Putting an animal with stress- or emotion-induced overeating on a diet may create three negative side-effects. It a) fails to deal with the stress and negative emotional factors causing the excess eating, b) decreases the animal’s ability to cope with said stress and negative emotions, and c) makes the animals desire for food even greater. Additionally and as several of my opening examples demonstrate, people who engage in emotion-induced feeding of animals may experience those same negative effects. That is, they need to give the food as much as their animals need to accept it.
One point that McMillan’s otherwise comprehensive article failed to address was overeating and obesity as these relate to the use of food as a reward, even though a Google Scholar search for “food reward overweight obesity children” turned up more than 22,000 hits. Why was this part of the problem ignored? This could be because, in spite of the human data regarding this connection in kids, few may wish to explore this possibility in animals for emotional or practical reasons. Emotional reasons could include the increased belief in behaviorism with its reward or punishment dichotomy as the only way to teach animals, followed by a shift toward reward as the only morally viable option when using it. Among the societal changes in the U.S. that facilitated this was the decreased knowledge of normal animal behavior and learning that accompanied the transition from a rural to suburban and urban society, which made it easier to assign companion animals a more symbolic identity. In such an atmosphere, behavioristic food-training seemed an enlightened way to go.
Further enhancing its allure, when food-training worked it provided a relatively fast teaching method that trainers and pet-owners found emotionally rewarding and researchers found practical. The more emotionally rewarding a teaching method the more people will offer it, and the more people will seek it for themselves and their animals. Within the research/academic community, a recurring response (including from some nutritionists) when I asked about the use of food-training in their laboratories and projects was, “I use it because it’s fast, it’s cheap, and it’s easy”. In academia where funding may be limited and time is money, this may be an important consideration. So in this case, too, it made good economic and practical sense to deny any negative effects of the food-reward approach.
Call me a pessimist, but much as McMillan’s article provides an overview of the eating-related scientific literature as it relates to stress and emotions that’s sorely needed, I suspect that the take-away message many veterinarians, behaviorists and trainers will get from it will be, “What drug(s) can I put these animals on to eliminate the stress and negative emotions that are causing them to overeat?”, the same question asked when food-reward training fails for some reason. Once again the focus will be on treating the effects instead of the causes because it’s easier and more convenient for us.
So while seeing McMillan’s article in a veterinary behavior journal made me feel hopeful that addressing the stress/emotional side of eating disorders in animals ultimately would receive the attention it deserves, I won’t hold my breath. It will require a major paradigm shift among the general public and the animal care professions before individuals can question the soundness of giving food to stressed animals during veterinary visits or training sessions. Or giving more psychoactive drugs to them to ensure their willingness to accept the food if the animals resist for some reason. Or recognizing the role the human-animal bond and human and animal emotions play in the entire spectrum of weight-related problems.
When any food-related approach is fast, easy and otherwise emotionally gratifying to us, it’s easy to rationalize that it’s an equally all-positive experience for the animal too. Not until the evidence regarding any damage to the animals outweighs those benefits will it be worth the time and energy to explore the full physiological, behavioral, emotional, and bond implications of our food-related choices as individual pet-owners and animal care professionals. As the response to any negative effects of pre-adult companion animal spay and neuter and over-vaccination makes clear, this could take a very long time.
If you have any comments regarding subject matter, favorite links, or anything you’d like to see discussed on or added to this site, please let me know at mm@mmilani.com.
Although records of numerous food-related human-animal dilemmas now fill my files, four situations that occurred relatively early in my veterinary medical career remain fixed in my mind because of what they taught me about the connection between food and human and animal emotions. The first involved an overweight dachshund with pancreatic problems that responded well to medical and dietary changes. Even so, periodically the dog would experience sudden bouts of incapacitating pain. And always the cause was the same. Even knowing how it would affect her cherished pet, the owner would succumbed to the dog’s pleading looks and perfect execution of every trick or command response he ever learned sans command. And she rewarded him with ice cream, chips, or whatever treat she happened to be eating herself at that time. The owner offered these deadly foods and the dog accepted them with both knowing the consequences.
Because neither owner nor dog was stupid, I wondered what compelled the two of them to display such destructive behavior. What possible emotional benefit gained from offering or eating that food could exceed its devastating emotional, physiological, and (for the owner) financial cost?
Score one point for emotions and zip for logic.
In the second incident, another very intelligent client and animal (an obese black Lab) co-created a food-based mutual adoration society. Like two old pals who regularly do lunch to affirm their relationship and in the process eat rich deserts they wouldn’t otherwise, this human-canine duo similarly injudiciously over-consumed. However in their case, they did it 3 times a day plus a bedtime snack every day, week after week, month after month. Back then I repeated the standard “fewer calories, more exercise” mantra that most veterinarians still repeat today, specifically mentioning that the shared peanut butter toast, heaping bowl of ice cream, and mac’ and cheese had to go. But even though tears trickled down his cheeks, my client made it clear that no amount of guilt-mongering on my part was going to work. “No,” he said. “I won’t do it. I can’t do it. It would kill us both.”
Score: Emotions 2, Logic 0
Then there were the weekend food-bingers who shared this activity with their pets. They would call late Sunday night or early Monday morning because their animals were throwing up. Was it something serious or merely a case of mild dietary indiscretion? Because they also were co-creators in the animals’ medical ailment, they didn’t want to go to work and leave the animals if their pets needed more immediate medical attention. Sometimes the calls would repeat, but most binge-food suppliers learned to recognize the signs and how to treat them at home. Note that they didn’t learn not to repeat the food-binging with their pets. They merely learned how to treat its effects themselves.
Score: Emotions 3, Logic 0
The forth incident sealed my determination to write my first book, The Weekend Dog. In addition to the Monday Morning Barfers (and Limpers, but that’s a different story), I noticed an uptick in the number of calls or appointments involving dogs with GI upsets mid-week. Being one of those possibly annoying people who want to know why something happens, it didn’t take long to determine the factors that combined to create this phenomenon. For one thing, all of these dogs attended the same training class the evening before, a class taught by one of the few area trainers who preferred to use the punishment option offered in behaviorism’s limited reward-or-punishment repertoire. For another, all these animals and their owners lived in the same part of town. Third, simultaneously the general public increasingly was being exposed to a blitz of food-equals-love advertising which made food seem like the very best reward one could possibly offer. The final factor took this particular food-related interaction beyond its tipping point: between the recreational center where the training classes were held and where these folks and their dogs lived stood the town’s first fast-food restaurant, a shiny new, highly advertised, easily accessible McDonald’s with its convenient drive-through window.
Need I say more? To owners distressed from watching their dogs jerked around or yelled at, those golden arches loomed with all the allure of El Dorado. They ordered burgers, fries, and shakes that they naturally shared with the canine pals who had endured this ordeal with them, as well as to relieve their own guilt for putting the dogs through that. But the dogs normally didn’t eat that kind of food, let alone under those highly emotionally-charged conditions. Their already emotionally stressed digestive tracts rebelled and responded with vomiting or diarrhea, and sometimes both.
Final score: 4-0, emotion wins.
As a naïve young practitioner I couldn’t understand how intelligent people who said they loved their animals could continue to engage in feeding practices that undermined their animal’s health in spite of the fact that they knew better. But eventually experience taught me that trying to impose a negative emotion like guilt on this process only would make the situation worse. What I didn’t understand was why.
Later when I started following articles about the placebo effect, then read about those matched fMRIs in empathic clinicians and patients (see last month’s commentary) I got an inkling of why co-created emotion-based food-related effects could be so potent. Because of this, when I received Franklin McMillan’s article “Stress-induced and emotional eating in animals: A review of the experimental evidence and implications for companion animal obesity” in the Journal of Veterinary Behavior, I couldn’t wait to read it.
In this article, McMillan does an excellent job of overviewing most of the causes of overeating addressed in the human and veterinary literature. Of the three causes—hunger, food restraint/restriction, and disinhibition—research indicates that disinhibition is strongly associated with weight gain and obesity in humans.
Disinhibition itself takes different forms. Habitual disinhibition refers to weight gain that results from exposure to readily available, palatable foods. McMillan points out that although most of the veterinary literature refers to caregiver overfeeding, i.e. habitual disinhibition, as the primary cause of obesity, this ignores the fact that not all animals overeat when provided with an abundant food supply as all those optimum-weight dogs and cats fed free-choice prove.
Individuals with situational disinhibition more likely overindulge under certain social circumstances, such as parties, sporting events, movies, etc. Although once again companion animal studies are lacking, I readily can recall animals whose owners commented on how the presence of another animal caused their otherwise picky-eaters to clean their bowls. Similarly there’s no shortage of animals who refuse to eat or eat only a minimal amount in their owners’ absence. Sometimes that person must even perform a specific mealtime ritual before the animal will eat.
Once again and as often happens in behavior, the opposite response may occur: some animals will eat more or in a more leisurely, less stressed manner if certain animals or people aren’t around during their mealtimes. Similarly many of the dogs I see with serious behavioral issues will obey commands flawlessly for food rewards in a secure physical and mental environment, but completely ignore that same command and reward in more stressful circumstances. Because those “other circumstances—such as when the dog spies the meter reader or the neighbor’s Chihuahua—are the ones in which obedience really matters, those who have no other teaching options often are reduced to trying more or “higher value” foods and even punishment. They don’t realize that the dog’s response makes sense because establishing and/or protecting the territory takes precedence of eating and drinking… But not always as we shall see. Suffice it to say that situational disinhibition may overlap with emotional disinhibition, the third form disinhibition may take.
Those experiencing emotional disinhibitiontend to overeat for emotional reasons, but the line between emotional- and stress-related eating is fuzzy at best. This occurs because stressed individuals typically display enhanced emotional states compared to those not stressed under those same circumstances. Human and laboratory animal research reveals that the elevated levels of glucocorticoids associated with stress trigger food consumption as well as emotional processing. Consequently those studying human overeating and obesity now accept that eating, and especially overeating, provides a mechanism that enables people to alleviate or cope with stress and negative emotions. In these situations, eating triggers the release of opinoids (substances with effects similar to that of opium) and as such serves as a form of self-medication.
Putting these two physiological components together, we have stress-related changes spiking the desire for food in some individuals, and eating calming that response via the release of opinoids. Because of the relationship between synthetic opinoids and addiction, it seems reasonable to suggest that failure to address the underlying stress or negative emotions associated with over-eating won’t resolve the problem no matter how many dietary and exercise changes are used.
And speaking of exercise, its addition to the decreased-calorie approach to weight-reduction also challenges the notion that weight-reduction possesses no emotional component in animals. One study that offered tantalizing clues to the role emotion may play in the exercise-weight puzzle takes us all way back to research conducted in 1963 by D. Premack and A.J.Premack. The Premacks discovered that rats with access to an exercise wheel significantly reduced their food intake, but significantly increased their food consumption when the wheel was removed. The rats didn’t eat more when the wheel was available to replace the calories lost during exercise; nor did they eat less when the removal of the wheel eliminated the need for so much food. On the contrary they did exactly the opposite. This suggests that the exercise benefited the rats in some way that exceeded the benefits of food consumption. McMillan notes that this is what one would expect if the exercise provided emotional benefits such as relief from stress or negative emotions.
Other conclusions from human and laboratory animal studies of value when considering a comprehensive approach to the problem of overweight and obesity in companion animals include:
One point that McMillan’s otherwise comprehensive article failed to address was overeating and obesity as these relate to the use of food as a reward, even though a Google Scholar search for “food reward overweight obesity children” turned up more than 22,000 hits. Why was this part of the problem ignored? This could be because, in spite of the human data regarding this connection in kids, few may wish to explore this possibility in animals for emotional or practical reasons. Emotional reasons could include the increased belief in behaviorism with its reward or punishment dichotomy as the only way to teach animals, followed by a shift toward reward as the only morally viable option when using it. Among the societal changes in the U.S. that facilitated this was the decreased knowledge of normal animal behavior and learning that accompanied the transition from a rural to suburban and urban society, which made it easier to assign companion animals a more symbolic identity. In such an atmosphere, behavioristic food-training seemed an enlightened way to go.
Further enhancing its allure, when food-training worked it provided a relatively fast teaching method that trainers and pet-owners found emotionally rewarding and researchers found practical. The more emotionally rewarding a teaching method the more people will offer it, and the more people will seek it for themselves and their animals. Within the research/academic community, a recurring response (including from some nutritionists) when I asked about the use of food-training in their laboratories and projects was, “I use it because it’s fast, it’s cheap, and it’s easy”. In academia where funding may be limited and time is money, this may be an important consideration. So in this case, too, it made good economic and practical sense to deny any negative effects of the food-reward approach.
Call me a pessimist, but much as McMillan’s article provides an overview of the eating-related scientific literature as it relates to stress and emotions that’s sorely needed, I suspect that the take-away message many veterinarians, behaviorists and trainers will get from it will be, “What drug(s) can I put these animals on to eliminate the stress and negative emotions that are causing them to overeat?”, the same question asked when food-reward training fails for some reason. Once again the focus will be on treating the effects instead of the causes because it’s easier and more convenient for us.
So while seeing McMillan’s article in a veterinary behavior journal made me feel hopeful that addressing the stress/emotional side of eating disorders in animals ultimately would receive the attention it deserves, I won’t hold my breath. It will require a major paradigm shift among the general public and the animal care professions before individuals can question the soundness of giving food to stressed animals during veterinary visits or training sessions. Or giving more psychoactive drugs to them to ensure their willingness to accept the food if the animals resist for some reason. Or recognizing the role the human-animal bond and human and animal emotions play in the entire spectrum of weight-related problems.
When any food-related approach is fast, easy and otherwise emotionally gratifying to us, it’s easy to rationalize that it’s an equally all-positive experience for the animal too. Not until the evidence regarding any damage to the animals outweighs those benefits will it be worth the time and energy to explore the full physiological, behavioral, emotional, and bond implications of our food-related choices as individual pet-owners and animal care professionals. As the response to any negative effects of pre-adult companion animal spay and neuter and over-vaccination makes clear, this could take a very long time.
If you have any comments regarding subject matter, favorite links, or anything you’d like to see discussed on or added to this site, please let me know at mm@mmilani.com.