EP 2.2: Biology and food
Welcome back to the second season of Triad Warriors: The Podcast!
On the last episode, we talked about what to expect in the upcoming season, More Than Food, and we also provided a brief overview of the many factors which contribute to the development of disordered eating… and honestly, any of our relationships with food, whether we struggle with a degree of disordered eating or not.
Our relationships with food (and bodies) do not exist in a vacuum. In fact, the way in which we experience food and view our bodies – whether that be our own bodies or other bodies – is largely influenced by cultural ideals, upbringing, and life experiences.
Moreover, the way in which we experience food and view our bodies is also often influenced by genetics and physiological processes – this is especially true for those who struggle with disordered eating, which is exactly what we are going to be talking about on today’s episode!
Today, I will be talking about the biological influences in disordered eating and eating disorders.
With that said, we are going to be getting into some of the science surrounding disordered eating and eating disorders, and regardless of whether YOU personally struggle with these issues or not, my hope is that you can still take something away from the episode. In fact, it was estimated that 40% of all Americans at least know one person who has struggled with a clinical eating disorder as of 2019. And this number is likely now higher due to the spike in cases that we have seen throughout the pandemic.
Further, 50% of all women and 45% of men are on a diet at any given time, which as we discussed last week, is a form of disordered eating.
Thus, this information will be valuable for everyone to hear, even if it cannot be applied directly to yourself.
The goal of this episode (and quite frankly, this entire season) is to remove the shame and stigma that surrounds disordered eating, eating disorders, and other mental illnesses. Ultimately, struggling in your relationship with food is nothing to feel guilty or shameful or embarrassed about.
Although, I completely understand those feelings if you have them. I myself have been in that place of shame and embarrassment. I myself have hidden disordered eating behaviors, and I myself refused to even admit that I had a problem for so many years. There is SO much stigma surrounding disordered eating and, consequently, SO many people are overlooked, undertreated, and pushed into the dark.
SO many people are told to simply “eat a burger,” or on the flip side, to simply “eat less” and “gain some self-control,” neither of which are helpful nor legitimate forms of advice.
In fact, as we will be discovering over the course of this season, eating disorders are NOT a self-control problem... Not even a little bit. They are not a sign of moral failure, and there are often MANY different REAL influences that have contributed to their development.
With that, I do want to issue a trigger warning, as we will be discussing eating disorders in detail. If you at any time feel as though this information is too much for you, please, please, please… turn the episode off, or pause it and come back later.
I do not think that this episode has as much potential to be a trigger as some of the other ones, particularly the ones where we will be discussing trauma, weight stigma, and other forms of oppression. This episode will mostly be filled with lots of science.
Nevertheless, I wanted to give you the heads up now. I wanted to give you the permission to leave at any time, should the need arise. Your mental health and overall wellbeing matters.
Ok… now that we have that all settled, let’s go ahead and get started!
EATING DISORDERS ARE PHYSIOLOGICAL TOO
For many years, eating disorders have been seen as the direct result of environmental and social influences, only – and they often are a result of these things… but only in part.
As I have already mentioned, eating disorders and disordered eating CAN be influenced by our weight-obsessed society and our extremely narrow, unrealistic beauty ideals. In fact, this is something that I talk about A LOT, particularly because I work with female athletes who are seeking to ditch the diet and establish a healthier relationship with food and their body.
I do not currently work with clinical eating disorders.
Nevertheless, eating disorders are physiological too. In fact, eating disorders are quite complex and can be caused by a wide range of pathologies, and risk factors can also include things like genetic predisposition, brain abnormalities, digestion, and negative energy balance.
Further, risk factors can include things such as perfectionism, body image dissatisfaction, impulsivity, behavioral inflexibility, co-existing mental health disorders, and more.
Evidently, there are a lot of reasons that someone might be struggling in their relationship with food and bodies. However, what I want to talk about today is the biological influences. What I want to talk about today is the genetic predisposition that places someone at a higher risk for going from “chronic dieter” to “eating disorder,” as well as the other physiological pathways that contribute to the development and maintenance of disorder.
GENETICS AND EATING DISORDERS
To begin, let’s talk genetics.
As I mentioned in my last episode, genetics accounts for 54-83% of the risk factors in developing a full-blown eating disorder. This a relatively wide range, but we must keep in mind that this statistic accounts for the diversity of eating and feeding disorders, each of which have their own causes and effects.
With that said, family studies have shown a 7-12-fold increase in the prevalence of both anorexia and bulimia if a first-degree relative struggled with disordered eating behavior (i.e., if a parent or sibling struggled with disordered eating). In addition, the “activation” of said genes is shown to occur during puberty, which explains why so many disordered eating behaviors began around teenage years.
The exact reasoning for this trigger is unknown, but it likely has to do with effects of changing hormonal environments… which makes sense.
I mean, you and I went through puberty. You and I experienced the horrors of middle school. You and I know the awkward and oily experience of a changing body and a pimply face all too well. Surviving the social scene of middle school was difficult, but for most, the uncontrollable changes to our bodies as we became young women (and young men) were confusing and uncomfortable — to say the least.
Add in peer influences, constant exposure to unrealistic media images, and now (apparently) schools suggesting shape wear to their students (WHAT?!) … and you have a recipe for disaster. Then, to top it all off, some experience a pubertal activation of genetic susceptibility, resulting in a gene- and social-environment that is primed for the development of disorder.
Now again, dieting does not guarantee disorder.
However, dieting IS another risk factor in the development of disorder, especially in those who are genetically predisposed to having an eating disorder.
And, considering the fact that 80% of all 10-year-old girls have dieted at least once in their lives, it makes SENSE that disorders such as bulimia, anorexia, and binge eating disorder often begin in adolescence.
That said, I do want to note that NOT ALL eating disorders and disordered eating develop during adolescence. Many women and men well into adulthood can develop these disorders. There are MANY causes and risk factors here… this is just ONE of those risk factors.
Further, genetic correlations can be passive, evocative, and active — a quick word on each.
Passive gene-environment correlations occur as a result of genetic and environmental exposures. Essentially, a child inherits genes from the same people who create their childhood environment, exposing the child to disordered thoughts and behaviors.
On the other hand, evocative correlations occur because the person has a genetic predisposition and, consequently, seeks out appearance-related comments from others. Similarly, active gene-environment correlations occur due to a disproportionate seeking. However, rather than simply seeking out comments and reassurance, the person might seek out environments that emphasize appearance (e.g., bodybuilding, gymnastics, dance, etc.).
Essentially, those who are prone to struggle with disordered eating and/or an eating disorder are more likely to seek out high-risk environments.
Again, these high-risk environments do not guarantee disorder. Neither does a genetic pre-disposition. But, mixing the two can be a dangerous combination.
I myself trained for and competed in bodybuilding for several years, following what I thought was recovery from my eating disorder. The truth… I was still struggling in my relationship with food and body, and bodybuilding simply became ANOTHER way for me to obsess over my body, exercise, and food. And, in many ways, my eating disorder was MORE suffocating and MORE dangerous in these years simply because my “lifestyle” was normalized and often even praised.
Other genetic risk factors for disordered eating can include a family history of depression and/or anxiety—both of which are linked to eating disorders—and a family history of substance use disorders. The reasoning for this has to do with the rigid perfectionism, anxiety, stress reactivity, negative emotionality, impulsivity, and/or harm avoidance that is found in some or all these disorders.
Basically… there are a WIDE range of influences that can cause someone to become especially vulnerable to the weight-centric, diet-obsessed fabric of our society… and we haven’t even touched on the Dietary Restraint Model of Binge Eating, nor the Minnesota Starvation Experiment yet… which let me tell you, is a very interesting and important experiment in the world of disordered eating! But before we get into that, let’s talk about Binge Eating pathways.
BINGE EATING PATHWAYS
According to NEDA (the National Eating Disorder Association) binge eating is the most common eating disorder in the United States, and there are several purposed pathways for binge eating. These include low self-esteem, problematic thoughts and beliefs about food, as well as dietary restraint. Because this is the episode on biological factors (and because this ties into the Minnesota Starvation Experiment), I want to focus only on the dietary restraint theory for now.
Essentially, the dietary restraint theory of binge eating asserts that restrictive eating is a precursor to binge eating, due to both biological and psychological reasonings.
BIOLOGY OF BINGE EATING
If you follow me on social media, then you have likely heard me discuss the psychological reasonings for this: restriction creates a preoccupation, which can FEEL like an addiction, but is actually the result of denied nutrition. With that said, the reasonings for this preoccupation are BIOLOGICAL as well.
Eating is one of the most basic human needs — Maslow’s hierarchy of needs is proof.
For those of you who are not familiar with Maslow’s hierarchy, allow me to explain briefly. Essentially, Maslow’s hierarchy of needs is a pyramid with 5 different levels. At the bottom of the pyramid is our physiological needs (i.e., food, shelter, water, sleep, etc.). From there, we move up the pyramid, with safety needs, followed by love and belonging, followed by esteem, and finishing off with self-actualization.
Currently, we live in a society that is OBSESSED with self-actualization. We live in a society that is obsessed with self-improvement, individualization, and climbing the perpetual ladder of “success”—so much so that our culture constantly attempts to jump past the first 4 categories, moving straight into self-actualization.
Let me tell you… hustle culture is JUST as toxic as diet culture, and the two are largely related.
The point is… for some reason (cough, cough weight stigma), we live in a culture that seems to expect humans to expend copious amounts of energy at the gym, work 24/7, and conquer the world, all while eating just enough to feed a toddler. (Reminder: 1200-1400 calories per day are the caloric needs of a toddler).
We live in a culture that is OBSESSED with restriction and the pursuit of thinness—neither of which our bodies enjoy.
In fact, our bodies are BIOLOGICALLY designed to counteract this restriction… you know, for survival. In the event of restriction, the hypothalamus responds as if you are in a famine and/or some other threat to survival. And for those who do not know, the hypothalamus is a region within the brain which controls the autonomic nervous system and the pituitary gland. Essentially, the hypothalamus helps to coordinate body functions such as body temperature, thirst, sleep, hunger, and emotional activity.
Thus, when our bodies encounter restriction—or what is interpreted as famine—our bodies trigger adaptive responses, one of which includes an increased release of neuropeptide Y and Ghrelin. Essentially, neuropeptide y and Ghrelin reduce energy consumption (i.e., metabolism) and increase urges to eat, particularly in the form of highly satiable foods—including foods high in fats and carbohydrates.
At this moment, your body WANTS you to eat because FOOD is the most basic human need.
Further, in times of restriction, the ventromedial hypothalamus also suppresses satisfaction cues and instructs your body to store any received nutrients as fat. This is a protective mechanism in case the energy is needed later due to prolonged famine.
The whole process is rather remarkable if you think about. In fact, this protective biological response CAN be helpful… in times of famine.
However, many of us are NOT experiencing famine. Yes, there IS a huge food insecurity issue in this country, which we will talk about later in the season. But, for those who are spending $15 on celery juice… this restriction is not done out of necessity and is likely causing more harm than good.
So, what does this all mean?
Well, if you have ever struggled with binge eating, or feeling out of control around food, then there is a BIOLOGICAL reason for your experience. There is a BIOLOGICAL reasoning for the out-of-body experience that led you to consuming multiple pints of ice cream, cookies, and a bag of chips. There is a BIOLOGICAL reasoning and, often, RESTRICTION is that reason.
RESRICTION is the precursor to binge eating.
Again, RESTRICTION (whether that be physically or mentally) is the problem. Not overeating. Even when you feel like overeating or “food addiction” is your problem.
I have seen it time and time again. In fact, 10/10 (and yes, I am daring to say 10/10) of the clients that I have worked with have come to me NOT eating enough, including the ones who struggled with binge-like tendencies.
When we restrict food (i.e., when we go on a diet), we create a situation where our bodies want and NEED us to eat. And our bodies have biological processes to help achieve that goal. This is why your diet has “failed” time and time again. This is why you have been unable to maintain an intake of 1500 calories for more than a couple of days, or weeks, or months.
You are not broken.
You are not flawed.
You do not lack self-control.
You simply have a body that is designed to meet your most basic human needs… and this is a GOOD thing. This is your body’s way of loving you and taking care of you. This is your body’s way of protecting you.
MINNESOTA STARVATION EXPERIMENT
With that said, let’s get to that Starvation Experiment that I had mentioned.
The Minnesota Starvation Experiment was an experiment conducted by Ancel Keys in 1944, as World War II was coming to an end. During World War II, many civilians in German-occupied Europe had experienced starvation, surviving on only bread and potatoes. Because not much was known about starvation nor nutritional rehabilitation at the time, Ancel Keys set out to find answers to the unknown.
Thus, to find his answer, he needed human subjects who were willing to undergo semistarvation followed by a period of refeeding. Now, I don’t know about you… but the ethics of Key’s experiment was quite questionable. I mean, starving people doesn’t sound like something that would fly today. But then again… this was 1944 and many of Key’s experiments were questionable on several grounds.
Nevertheless, Key’s found 36 healthy men who agreed to partake in the experiment as an act of service to their country.
During the experiment, the men we closely monitored. For the first 3 months, they were fed approximately 3,200 calories per day (because THAT is a NORMAL amount of food that a grown adult should be eating), and they were assigned to partake in various housekeeping and administrative tasks. They were also expected to walk 22 miles per week throughout the ENTIRE duration of the experiment.
After the first 3 months passed, then came the starvation period. Over the course of next 6-months, the men received 1,600 calories per day, which was considered semi-starvation…
Let’s pause for a second.
1600 calories per day. Semi-starvation.
Are you making the connection here?
1600 calories per day is considered semi-starvation for a grown adult. And yes, these are men, not women. But women do not need a significantly less amount of food than men.
1600 calories per day is MORE than the 1300, 1400, and 1500 calories that so many men and women are attempting to eat daily… and THAT was considered semi-starvation.
Anyhow, the men ate 1600 calories per day for 6-months, which was increased or decreased weekly based on whether or not the men were meeting the weight loss requirements. Moreover, during this span of time, the men were expected to continue their work and to continue walking 22 miles per week… and the outcomes were horrific.
So much so that Key’s regretted ever putting the men through so much distress.
During the experiment, the men experienced increase anxiety, irritability, and personality changes. Their tolerance for cold temperatures diminished, and symptoms of dizziness, fatigue, muscle soreness, hair loss, and reduced coordination appeared. The men lost all interest in women and dating due to decreased sex drive, and two men were even admitted to the psychiatric ward due to psychological distress.
Further, the men became extremely preoccupied with food… which makes sense given everything we just discussed about neuropeptide y and the biology of restriction.
In fact, one man broke his diet and was excused from the experiment. Several others collected cookbooks, one of which had 100 by the end of the experiment and eating became a ritual for most. Several used disordered habits to make their small portions feel larger, and one man rushed into a doughnut store, buying a dozen doughnuts which he gave to some children outside just so he could watch them eat.
For the most part, the men stayed committed to the experiment, but this was not without distress. And the proceeding 3-mont rehabilitation process was not any easier. In fact, many of the men complained that their hunger simply could not be quenched, and some men even lost more weight upon initial refeeding due to the loss of excess edema fluid. Most men needed more than 4,000 calories per day over the course of 3-months in order to restore their weight, but none of the men felt “back to normal” after the rehabilitation period had ended.
If you are interested in learning more, you can look up the experiment, but the point is… restriction can cause us to behave anxiously and chaotically around food. And that is normal. That is part of your body’s famine response.
Further, dieting and restriction can lead to things such as:
Nutritional deficiencies
Hormonal changes
Reduced bone density
Menstrual disturbances
Reduced metabolism, and
Eating disorders (for the reasons already discussed)
ED BEHAVIORS ALTER REWARD RESPONSE IN THE BRAIN
Disordered eating behaviors (like restriction) also alter the reward response and food intake control circuitry of our brains, further reinforcing said behaviors. In fact, in women with ED’s, binge behaviors were associated with lower prediction error response, and restrictive food intake was associated with a higher prediction error response, strengthening their ability to override hunger cues.
BRAIN STRUCTURES AND ED’S
In addition, eating disorder behaviors have been shown to alter grey and white matter volume within the brain. I do not want to get into too much of the science because we have already covered a lot in this episode, but in brief, I will explain some of the findings.
In all ED groups (including BN, AN, and BED), an increased gyrus rectus volume has been found. In ED’s, the gyrus rectus is associated with a stronger sensory experience of food, which may cause eating to feel overstimulating and/or overwhelming. This leads to an increased reward and punishment sensitivity that may cause some to avoid food.
Further, an increased insula volume has been found. Essentially, the right anterior insula is associated with self-regulation, as well as interoceptive awareness. Therefore, a fixed perception of “being fat” may be related to the increased volume of this region. Similarly, the increased volume of the left anterior ventral insula may be responsible for certain eating behaviors. This region of the brain is related to gastric distention and fullness. Thus, an increased volume may interfere with fullness and satisfaction signals, as well as urges to purge.
CONCLUSION
The point is: disordered eating is not a problem of self-control, nor is it something to be ashamed of. There are real, biological (as well as psychological and environmental) influences that contribute to eating behavior—in the same way that real, biological influences contribute to the development of other illnesses and disorders.
And if you or anyone that you know is struggling with any degree of disordered eating, I urge you to reach out for help. There is NO such thing as sick enough, and you can seek help at any point in your journey.
With that said, I do not work with clinical eating disorders. If you feel as though you or someone you know is struggling with an eating disorder, then please reach out to the appropriate level of care. The National Eating Disorder Association has a helpline, which I listed in the description of this episode. If you call or text that number, someone can help link you to resources in your area. You are not broken, and help is available.
Anyhow, we are just about wrapped up with the episode for this week! I hope this was an informative and eye-opening episode. There are many, many factors which influence eating behavior and contribute to the development of eating disorders, and we are only just getting started with the season!
Tune in next week for a discussion on Digestion and Disorder with Dr. Charlotte Nowak, ND. Thank you for listening and I hope you have a great day! I am Annie Randall, this is Triad Warriors, and food freedom starts here!
