Chapter 18: Eating & Feeding Disorders

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Welcome back to The Deep Dive.

Today, our mission is tackling eating and feeding disorders.

These are, well, they're known to be some of the most complex and frankly potentially lethal psychiatric conditions out there.

Right.

And it's crucial, I think, to start by framing them correctly.

The sources really emphasize seeing these disorders on a spectrum, kind of like autism.

Oh, OK.

Not just six categories.

Exactly.

Symptoms can shift.

They can wax and wane over a lifetime.

Think about it like depression or even substance use disorders.

It's not always constant.

Makes sense.

So today, we're diving deep into, let's see, anorexia nervosa, bulimia

binge eating disorder and also those feeding disorders people might hear less about.

That's the plan.

Focusing on the biopsychosocial aspects and, really importantly for our listeners, the nursing implications.

All right.

Let's start with anorexia nervosa, AN.

The absolute core, from what I read, is this incredibly intense fear of gaining weight.

It drives everything.

It really does.

But what's fascinating and maybe a bit unexpected is that it's not just psychological willpower against hunger.

The research shows individuals with AN actually have significant differences in how they experience taste, appetite, even satiety, that feeling of fullness.

So their basic body signals are different.

In a way, yes.

And these differences kind of help keep the disorder going.

Think about your own experience, usually.

Eating feels good, satisfying, right?

Yeah, usually.

Relief, comfort, maybe.

For someone with AN, though, eating can trigger intense fear or anxiety, sometimes even panic.

And restricting food, that actually relieves the anxiety.

Wow.

Okay, so restriction becomes the safe feeling.

And when we talk about purging or compensatory behaviors here, it's broader than just vomiting?

Oh, absolutely.

Purging can mean self -induced vomiting, sure, but also things like exercising excessively, misusing laxatives, diuretics, even stimulants or thyroid meds to control weight.

That relief mechanism sounds powerful.

What's driving it biologically?

Is there a

A big one.

Hairability estimates are around 50 % to 60%.

And interestingly, there are genetic links, not just to mood and anxiety disorders, which maybe isn't surprising, but also to variations in how the body handles glucose and lipids.

So basic metabolism differences could play a role.

It's suggestive predisposition, yeah.

And there's this neurobiological cycle involving tryptophan and serotonin that's really key.

I saw that.

Tryptophan's an amino acid when you only get it from food, right?

Yeah.

And it's needed to make serotonin.

Exactly.

So if you restrict your diet, your tryptophan levels temporarily drop.

This can actually lead to a brief decrease in anxiety or dysphoria for these individuals.

Wait, less tryptophan feels better.

That seems backward.

It does, but it creates this reward for restricting calories, a positive feedback loop.

And then the body's survival response kicks in.

The hypothalamus activates.

Cortisol and dopamine are released to signal eat.

Which should make them hungry.

But the patient often interprets those physiological signals not as hunger, but as a threat to their sense of control.

So what do they do?

They restrict even harder.

Goodness.

So the body's attempt to save itself is perceived as the enemy.

That really explains why AN is called ego -syntonic, doesn't it?

The person values the disorder, sees it as part of their identity, linked to perfectionism, control.

Precisely.

It's like a fortress, as you said.

And often there's difficulty recognizing emotions, what we call alexithymia, and very low distress tolerance alongside it.

Okay, shifting to assessment.

From a nursing perspective, what are the immediate physical red flags?

You're looking for the signs of severe malnutrition.

Low blood pressure, low pulse, low temperature.

Those are critical vital sign changes.

And specific things like that fine hair.

Yes, lanugo.

It's the body trying desperately to stay warm.

Also, sometimes yellowish skin, hypercarotidemia because the metabolism of carotene is altered,

and peripheral edema swelling, especially in the legs or feet.

Why the edema?

It can be from low protein, specifically albumin in the blood hypoalbuminemia, or ironically it can happen during the refeeding process itself.

And severity is judged by BMI.

It's a key indicator.

Mild AN is considered a BMI of 17 or slightly above, moderate is 16, 16 .99, severe 15, 15 .99, and extreme is anything below 15.

It really drives home how vital these behaviors feel to the patient.

For the listener,

try to imagine being told to suddenly stop the one thing, the only thing that makes you feel safe and in control.

That's what we're asking.

Absolutely.

And that's why the threshold for hospitalization is quite specific.

Things like weight below 75 % of ideal body weight, a heart rate persistently below 50, maybe even 40, severe electrolyte imbalances, cardiac issues.

Okay, so they're admitted.

We start nutritional support.

But you mentioned a danger zone there.

Yes, a critical one.

Re -feeding syndrome.

This is potentially lethal.

Why is simply giving food dangerous?

Because the body has adapted to starvation, running on fats and proteins.

When you suddenly reintroduce carbohydrates, the metabolism shifts violently back to using glucose.

This shift pulls essential minerals out of the bloodstream and into the cells very rapidly.

Which minerals are we most worried about?

Primarily phosphate, magnesium, and potassium.

Severe drops, hypophosphatemia, hypomagnesemia, hypokalemia can cause delirium, seizures, heart failure, respiratory failure.

It's incredibly serious.

So re -feeding has to be slow, methodical?

Extremely.

Slow, therapeutic nutrition is key.

It dictates the whole inpatient approach.

Right, the milieu management.

Structured meal times, supervision after meals for like an hour, right?

Monitoring trips to the bathroom, limiting excessive movement.

Exactly.

Even weighing patients facing backward on the scale to try and lessen the intense anxiety around the number itself.

And treatment -wise, just to confirm, no specific FDA -proof meds for the core symptoms of AN itself.

Correct.

We treat the co -occurring issues, depression with SSRIs, anxiety with anxiolytids, but not the AN directly with medication.

For adolescents, family -based treatment, FBT, shows the best results.

Okay, that gives us a solid picture of AN.

Now, bulimia nervosa, BN.

It feels quite different, particularly because weight isn't always the defining issue, is it?

That's a major contrast.

BN involves these recurrent episodes of binge eating, and we're talking huge amounts, maybe 1 ,500 to 5 ,000 calories in a short time, like two hours.

Followed by compensatory behaviors to prevent weight gain.

Right.

Vomiting, laxatives, diuretics, excessive exercise, fasting, the same kind of behavior as we see in the purging subtype of AN, sometimes.

But the key difference is that people with BN are often at a normal weight, or maybe slightly overweight.

Their self -worth, though, is still intensely tied to body shape and weight.

When does BN typically emerge?

It often peaks a bit later than AN, maybe late adolescence or young adulthood.

About 1 % to 1 .5 % prevalence in young women.

And comorbidity is really high.

Like what?

Depression, anxiety disorders, bipolar disorder, definitely substance use disorders, PTSD, and quite often borderline personality disorder.

And the biology.

Similar heritability to AMN.

Pretty close, around 60%.

Neurobiologically, there are links to serotonin again, specifically impaired transport affecting satiety that I'm full signal might be weaker or delayed.

Making it easier to keep eating during a binge.

Potentially, yes.

And there's evidence involving dopamine pathways, too, suggesting increased reward sensitivity.

Also, that feeling of relief or calm after purging, that might actually be linked to a rise in plasma endorphins, the body's natural opioids.

Oh, so the purge itself becomes reinforcing chemically.

It appears so, yeah.

Which helps lock in that binge purge cycle.

Assessment -wise, what are the physical clues nurses look for with BN?

Because of the frequent purging, especially vomiting, you look for things like enlargement of the parotid glands right below the ears, giving a sort of chipmunk cheek appearance sometimes.

And dental problems.

Definitely.

Dental erosion, cavities, loss of enamel from the stomach acid, and then there's the Russell sign.

That's the marks on the hand.

Yes.

Calluses or scars on the knuckles from repeatedly inducing vomiting by scraping against the teeth.

It's a pretty specific sign.

Now, you mentioned AN is egocentonic.

BN is different.

Generally, yes.

BN is often experienced as egodistonic.

The person usually feels distressed, ashamed or out of control because of the purging.

They see it as a problem.

They might be more open to getting help.

Often, yes.

Establishing a therapeutic alliance can be a bit easier initially compared to AN, but the anxiety cycles are still incredibly powerful.

The book had that example, Iris, right?

Yeah, the diuretic use.

She stopped, got swollen from fluid rebound, panicked and started the diuretics again.

Exactly.

It shows how easily that cycle reinforces itself, driven by intense anxiety about perceived weight gain or body changes.

Okay, treatment.

Big medication point here.

Huge fluoxetine or Prozac is the only FDA -approved medication specifically for bulimia nervosa in adults.

And often, it's used at higher doses than typically used for depression.

And the critical warning.

Bopropion, well, butrin, is an absolute contraindication.

Do not use it in patients with BN or any purging behaviors.

It significantly increases the risk of seizures in this population.

Got it.

Crucial safety point.

And therapy -wise.

Cognitive Behavioral Therapy, CBT, is really the first -line approach.

It focuses on identifying and changing those distorted thoughts about food, weight, and self -worth, and developing coping skills.

Integrative things, like yoga, have also shown promise for reducing anxiety, especially around meal times.

Alright, that brings us to the third major one.

Binge eating disorder, BED.

How is this distinct?

BED involves those recurrent binge eating episodes, similar in scale to BN, causing significant distress.

But the key difference is there are no regular compensatory behaviors like purging or excessive exercise afterward.

And because there's no compensation, it often leads to?

Obesity, yeah.

Though not always, but it's a very common outcome.

The DSM -5 criteria really focus on the context and feeling around the binge.

Eating much faster than normal, eating until uncomfortably full, eating large amounts even when not physically hungry, eating alone out of embarrassment.

And feeling disgusted, depressed, or very guilty afterward.

Right, that distress component is essential for the diagnosis, and BED is actually the most common eating disorder.

Lifetime incidence is around 3 .6 % in women, higher than AN and BN combined.

What about the drivers?

Similar to BN.

There are overlaps.

High impulsivity seems to be a factor, maybe heightened reward sensitivity, particularly to those highly palatable foods, high sugar, high fat.

It can feel almost like an addiction for some.

So for assessment, the challenge is differentiating BED from obesity that might be due to other lifestyle factors.

Exactly.

Nurses need to assess carefully.

Because of the repeated large volume intake during binges, you often see associated GI problems, chronic heartburn, difficulty swallowing, dysphagia, bloating, abdominal pain, diarrhea.

The stomach gets stretched repeatedly.

And the approach needs to be sensitive.

Very.

Using non -judgmental language is key.

Phrases like unhealthy weight might be better received than a weight problem or obesity.

The counseling focus really needs to be on identifying emotional triggers for the binges.

Because, as the saying goes.

It's not really about the food.

It's about using food to cope with emotions.

Tracking those feelings and finding alternative coping strategies is central.

Is there medication for BED?

Yes.

Lisdexamphetamine dimethylate, brand name Vyvanse, is FDA approved for moderate to severe BED in adults.

It's a stimulant which can help reduce binge frequency.

And what about bariatric surgery?

It's sometimes considered for severe obesity.

It's controversial for people with active BED.

While it can lead to initial weight loss, if the underlying binge eating behaviors aren't addressed through psychotherapy, they often return post -surgery, sometimes in different forms, and it limits the long -term success.

Therapy is crucial alongside any surgical consideration.

Okay.

That covers the main three eating disorders.

Let's touch quickly on the feeding disorders.

These usually start earlier, right?

Typically in childhood,

yes, although they can persist or even appear later.

There are three main ones outlined.

First is Pica.

Right.

Pica is persistently eating non -food, non -nutritive substances.

Things like dirt, clay, paint chips, paper, hair.

Sounds dangerous.

It definitely can be.

Risks include poisoning, like lead toxicity from paint chips, intestinal blockages or perforations, infections from contaminated soil, dental damage.

Intervention is mainly behavioral, close monitoring, preventing access, and rewarding appropriate eating habits.

Okay.

Second is rumination disorder.

This involves repeated regurgitation of food.

The food might be re -chewed, re -swallowed, or spit out.

It has to happen for at least a month and isn't due to a medical condition like reflux.

When does this usually start?

Often in infants, typically between 3 and 12 months, sometimes neglect or poor caregiver interaction can be a factor.

Interventions might involve simple things like repositioning the infant during and after feeding, or focusing on improving the caregiver -infant relationship.

And the third one, ARFID.

Avoidant restrictive food intake disorder, or ARFID.

This is where someone avoids or restricts food intake significantly, leading to consequences like weight loss, nutritional deficiencies requiring supplements or tube feeding, or major interference with social functioning.

But crucially, it's not about body image.

Exactly.

That's the key distinction from anorexia nervosa.

With ARFID, the avoidance is usually due to things like lack of interest in eating, concerns about negative consequences of eating, like choking or vomiting, maybe based on a past experience, or hypersensitivity to the sensory aspects of food.

The texture, smell, taste, appearance.

So treatment focuses on?

Behavioral modification is the primary approach.

Gradually expanding the variety of foods accepted, maybe using rewards, desensitization techniques.

Sometimes therapy addresses underlying anxiety if that's a factor.

Okay, we've covered a lot of ground.

If you had to synthesize the absolute core takeaways from the sources on AN, BN and BED for our listeners, what would they be?

I'd say think of them by their primary crisis point.

AN, that's the severe restriction, the low weight crisis, and the hidden danger of refeeding.

BED, that's the chaotic binge purge cycle, the electrolyte crisis, and potential long -term physical damage.

BED, that's the recurrent binge without compensation, often leading to an obesity or GI crisis driven by emotional coping.

And underpinning all of them.

Deep complex biopsychosocial roots.

Genetics, neurotransmitters like serotonin and dopamine,

reward pathways, psychological factors like control and perfectionism, emotional regulation issues, and definitely that overlay of societal pressure.

It's never just one thing.

Right, which leads to a final thought for you, the listener.

Given these really strong biological and genetic factors we've discussed for all these disorders, how much harder does recovery become when you layer on our culture's intense focus on thinness?

Could these environmental pressures actually interfere with or maybe even prevent long -term recovery?

Does it help explain that staggering 50 % one -year relapse rate we see in AN?

Something to really consider biology meeting society head -on.

A really important point to reflect on.

Thank you for learning alongside us in this deep dive into the source material.

And thank you for joining us from the Last Minute Lecture Team.