Andrew Chapman | Longreads | April 18, 2024 | 3,755 words (13 minutes)

At first, it was simply a roast chicken recipe. Then it was everything.

I watched a man on YouTube cook the chicken, imagining what it would be like to taste it. Even if he had prepared it in front of me, I couldn’t have eaten it. Inflammation from Crohn’s disease had connected the tissues of my small intestine and my bladder together via fistula, and I did not want to pee out a roast chicken.

Instead, I was on a form of artificial food called total parenteral nutrition (TPN, for short). All my nutrition and water were pumped from an IV bag into my veins through a tube in my arm. Even though I had enough functional nutrition in my body my brain screamed, you’re hungry, constantly. 

I watched Gordon Ramsay make French pan sauces and tuna with lime zest. I watched a man on Netflix who seemed to know nothing about food eating Khao soi in Thailand. Watching cooking shows felt like picking a scab—somehow like relief and suffering at the same time. 

Eventually, my wife, Erica, became concerned for my mental health. “I can’t stop. It’s a compulsion,” I would say. 

“I hate it,” she’d add. 

To diminish her concern, I settled for watching Anthony Bourdain’s Parts Unknown, because the show’s travel element obscured the food.

Crohn’s is an inflammatory bowel disease. The cause is unknown, but it appears to be due to a haywire immune system that attacks the digestive tract—in my case, the end of the small bowel. Every Crohn’s patient experiences different symptoms. Some have daily mild belly aches and unruly diarrhea. I’ve always experienced near-normal health punctuated by periods of wild pain, nausea, and weight loss. The most common treatments are steroids, anti-inflammatory and immunosuppressant drugs, and, as a last resort, surgery to remove any bowel beyond repair. In my thirties, the combination of fresh inflammation and scar tissue from a teenage surgery had blocked up my bowel. Eating became like gambling—sometimes I won, but mostly I lost.

I was diagnosed at 11. Food had become repellant to me. I remember sitting, twig thin, in an emergency room waiting area with my worried parents. A cooking show was on TV. The show’s host was making a cheese omelet that looked as appealing to me as fried fertilizer. “I can’t even look at that,” I said. 

“Oh? That looks good to me,” Mom said, aiming less to change my mind on the omelet than confirm to herself how sick I was.

The year after I was diagnosed my doctor, worried I was losing so much weight I wouldn’t get enough calories through regular eating, put me on a nutritional therapy called enteral nutrition—an infusion of milky formula into the belly. I had to snake a flexible rubber tube up my nose and into my stomach every night, tearing it out in a rush before school in the morning. The tube would sometimes disconnect from the IV bag while I was sleeping, the pump whirring away until morning. I’d wake up drenched in sticky formula with an empty stomach. 

When my doctor gave me the option, I chose to guzzle the formula during the day to have extra hours without the tube at night (drinking the volume of formula required for nutrition would have been nearly impossible). I was also allowed to drink clear fluids, so my parents kept the fridge stocked with lemon-lime soda and JELL-O. But, without that shackle of a tube, I would not have stayed alive as a preteen. 

Doctors have used enteral nutrition since the early 20th century, pumping broths and formulas directly into the stomach either through a tube placed into the nose and down into the stomach, like mine, or through an incision in the belly. However, enteral nutrition relies on patients having a working digestive system. Doctors thought it was impossible to bypass the digestive tract and get enough nutrition into patients through a vein, believing it required so much liquid, and such a high concentration of chemical nutrients, that it would cause inflammation and burning when administered.

It was Stanley Dudrick, a strong-minded surgical resident at the University of Pennsylvania, who would change that. One weekend in November 1961, Dudrick was left to look after three surgical patients. The patients had had different procedures, but over the weekend, all three died. Having watched his supervisor, Dr. Rhoads, a revered surgeon, perform technically flawless surgeries on each of them, Dudrick concluded their deaths were his fault. When he told Rhoads on Monday, he was assured the patients were all frail from their operations, and their gastrointestinal tracts were struggling to absorb enough nutrients to overcome the weakness. The patients didn’t die from his ineptitude—they died of malnutrition. 

A fire was lit in Dudrick. He requested leave from his surgical internship and worked out of a small lab in the hospital’s basement, determined to find a solution. For years, he honed the composition for a nutrition formula that could be delivered via veins, avoiding the intestines. By the late ’60s, he had finally found a stable mixture of water, carbohydrates, proteins, trace elements, fats, salts, and multivitamins—everything you need from a balanced meal, just with the color and smell of Elmer’s glue. 

But the concentrated nutrients did burn. “I’ve actually put it in my own vein,” Dudrick told Dr. Rhoads, showing his forearm. “It burns like liquid fire.” To banish the blaze, he knew the formula would have to be injected close to the heart, to allow for fast dilution around the body. When he kept a beagle named Stinky alive, nourished only with the nutrient combination infused into his vena cava (a large vein that returns deoxygenated blood to the heart), Dudrick was convinced it would work for humans. He’d invented TPN. Since then, it has saved millions of lives.

A doctor once told me that when a tissue is inflamed for long enough, the connections that hold cells together start to break down, and the tissue softens. When that happens, tissues can merge, forming a little tunnel known as a fistula. A CT scan showed that my bowel had formed several fistulas looping on themselves—the path of digestion more a maze than a hallway. 

By knocking back the immune system with immunosuppressants and nutrition from TPN—to rest the bowel by not eating or drinking—fistulas can sometimes close themselves. This was the hope for me. 

A thin IV catheter called a peripherally inserted central catheter, or PICC—like the one Dudrick used in Stinky—was placed in a vein on the inside of my arm and threaded into my vena cava. A nurse named Stan inserted the PICC with the intense focus of a true craftsman. He wore earbuds and sang “I can’t get enough of your love” by Barry White under his breath.

Since I would be sent home with the TPN, a different nurse taught me how to rig it up myself. She explained how I would set up the TPN every night and run it over 12 hours. I had to inject a personalized pre-prepared slurry of multivitamins into an IV bag, prime the pump, and flush the PICC with saline. She explained the buttons and the beeps on the pump that squirted the mixture through the tubes and into my body. Everything was vigorously wiped with alcohol because any bacteria would be injected straight into my heart. 

“You got all that?” the nurse asked after her demonstration.

I had been preoccupied thinking about how weird not eating would be at home. Like many thirty-something married couples in San Francisco, Erica and I lived with five other tirelessly social roommates. One ran a start-up from the living room. The house was often standing room only. And what did people do when they hung around in groups? They cooked and they drank. Early on in the flare-up, the group shared a rich and earthy-tasting homemade coq au vin. I helped to meticulously peel dozens of pearl onions. I paid the price later that night.

“I think we’ll be okay,” I said to the nurse. 

We weren’t. At home that first night, we fumbled to inject the components into the bag and attach it to the pump and my arm. Then Erica spotted a bubble marching up the tube, and we mashed at the stop button on the pump. 

“That’s fine, right?” I said.

“I don’t know. What if it explodes your heart?”

Out to the kitchen, Erica went. 

Polling the two dozen or so people cooking in the house, she found one doctor and one nurse to choose from. The bubble could stay; the feeding began.

On one of the first nights at home, Erica’s best friend visited to apply therapeutic face masks to pass the time. In a selfie with our dingy-green masks, Erica beams with sweet enthusiasm. I look stone-faced and far away. Our housemate Rory later brought some puzzles for us to do together. Everyone in the house became obsessed with them. I could hear them celebrating a discovered piece long after I snuck away to lie down. I felt weak from being sick. But I also felt weak for not being stronger, for not executing a gracious interest in the ways people tried to help.

Those first weeks, I mostly slept. When I was awake, my brain was frighteningly alert. My body, on the other hand, looked and felt like wet cardboard. The anxiety of hunger settled under my ribs like the feeling you get when you’re about to burst into tears. The hum of the refrigerator alone was enough to make me want to bury my head in the backyard. I often dreamt of donuts, and once, of my sister-in-law’s mother, a tenacious Serbian woman, bringing me a roasting pan full of sausages. By the time I had my first dose of TPN, I had gone without eating for nearly a week and a half, sustained only by fluids in the hospital. Then, due to a holiday and clerical error, I was left on a dose half of what I required—intended to see how well I handled the slurry—for a week longer than expected. I assumed the hunger would subside with enough nutrition. But even after weeks on full TPN, I still could’ve eaten the plastic bags it came in.

Everyone starts with around 22 feet of small bowel, but if surgery cuts it down to less than seven feet, the body can’t absorb water and nutrients anymore. With my bowel so badly matted together, surgeons might need to remove a lot, and if they removed enough—on top of the two feet I lost as a teenager—it could mean TPN for life. With the state my mind was in, that was unimaginable.

While scientists have figured out extraordinary ways to keep patients who can’t eat alive, they haven’t yet figured out how to deal with what it does to us mentally. I’d been through a lot with Crohn’s before, even believing that who I was as a person was largely the result of these struggles. But TPN was different. It was like I was sitting in a lawn chair (albeit a rickety one) at a picnic when somebody came along and kicked a leg out—the pasta salad that might’ve been in my hand, flung into oblivion.

Eating is an experience that humans share with all other animals. Organic material is consumed and broken down during digestion. In return, the body adapts nutritious molecules into a host of cellular processes and adenosine triphosphate, or ATP, which cells turn into energy. During digestion, physiological responses are triggered in the brain by the vagus nerve, contributing to the feeling of fullness. Hormonal signals also act on the brain: leptin, a hormone produced by fat cells, sends signals to the hypothalamus to inhibit hunger. In patients on TPN or enteral nutrition, leptin does increase after infusions, but it doesn’t appear to be well correlated with decreased hunger.

While the hormones and neural signals are crucial to satiation, so is the sensory experience that takes place during the first phase of digestion—the cephalic phase—which begins at the sight of food. The pleasure that we take during this phase appears to be important to feeling satisfied. Monkeys on TPN continued to eat real food even when their caloric needs were met. Studies in healthy humans found that people on TPN reported being as hungry as those injected with only lactated Ringer’s, a solution designed to replenish electrolytes and fluid rather than calories. I asked an on-call gastroenterologist once what I could do for the hunger.

“You can try chewing meat and spitting it out,” she said. 

“Oh,” I said. 

Of all the things doctors have said to me, this struck me as the most deranged. I never even considered her advice because I didn’t miss the taste of food, so much as I missed the social aspect and, more so, not feeling hungry. Carrying a spittoon to spit out chicken like a confused cowboy wasn’t going to accomplish either. But now I begrudgingly admit she was on to something. Chewing food, even without swallowing, helps to activate the cephalic phase, triggering a partial sense of satiation. The doctor never explained this to me.

Paul Smeets, a nutritional neuroscientist at the University Medical Center Utrecht in the Netherlands, told me that part of the problem is that patients on enteral and parenteral nutrition receive the infusion over such a long period. “They sneak nutrition into people so slowly that the brain is never aware it’s happening,” he told me. The homeostatic feedback produced from eating a meal, that allows the brain to feel satisfied, is missing. TPN and enteral nutrition are, in effect, a form of sensory deprivation. My hunger was a natural neurological reaction that could be traced back for millennia.

While on TPN, I stayed away from the kitchen as best I could, mostly because it felt as if I was gawking. In the evenings, Erica would come home from work and I’d close my laptop screen, where Bourdain was, say, fishing for dinner in southern Italy, and we’d lie on the bed. Erica would ask if I farted out my penis that day. I’d say not today, and then we’d laugh at the ridiculousness of what a good day looked like. She ended up eating less. Family members of patients on artificial nutrition often feel guilty about eating, some even lose weight, I learned. This unearthly relationship with food wasn’t what I wanted to offer her, but it was what I served, like pulling out a burnt tray of hors d’oeuvres just as the guests arrived. Even though she smiled and accepted our life the way it was, we hadn’t even been married for a year. I wondered if anything so young could thrive so undernourished.

While she was out, hidden in our room, I gorged on the cooking shows that caused her concern. In the late ’70s, doctors learned that patients on TPN often experience several stages of adaptation, including grief—mourning the loss of food rather than the death of someone close. Watching cooking shows seemed like a form of remembering and searching for what I had lost. When I tried to stop, I felt like I was from a different planet, separate from everyone else whose lives swirled around food. When watching cooking shows, I could fake being human. Since the cephalic phase of digestion begins at the sight of food, even before putting a crumb in one’s mouth, it’s also possible I was subconsciously attempting to veer onto an ancient road to satiety even if, for me, it didn’t lead anywhere.

When I went looking on the internet, I found I was not alone. I asked why people watched cooking shows on the Crohn’s disease subreddit. One user said they had no idea, but “the only show I watched was Diners, Drive-Ins and Dives with Guy Fieri, which is extra weird because I was a vegetarian.” Another bought cannoli and made their partner describe the taste in detail as if it were their own personal cooking show.

The things that I, and others on TPN, experienced, are not unlike the psychological effects seen in people who are physically deprived of food. In 1944, 36 men entered a study after seeing a brochure passed out at the University of Minnesota asking, Will you starve so that others will be better fed? The 36 participants were underfed until they lost 25% of their body weight. As the experiment progressed, Ancel Keys, the nutritionist running the study, noticed odd psychological effects. The participants became increasingly focused on food, collecting recipes, and taking down pin-ups of women to hang pictures of food. One even decided he would change careers and become a chef. After the study, most participants gorged themselves long after their weight returned to normal. 

Without food, we become preoccupied with it. Food is as evolutionarily important as pain and sex. Animals that don’t take an interest in these stimuli don’t fare well. Research shows that noticing food and remembering its location is a base instinct for all humans that becomes heightened when hungry. 

Patients on TPN are functionally fed but are perhaps not neurologically aware of it. Of course, physiological food deprivation is different (unimaginable, to me) from a psychological one, but we still seem to hyper-focus on what we can’t have rather than shy away from it. With the way appetite brain signaling works, Smeets says it makes sense that some overlapping effects of starvation might take place in the brain, causing an obsession with food and all the behavioral baggage that comes with it.

After nearly a month without anything, not even water, by mouth, my symptoms stabilized and my doctor said I could try drinking clear liquids. Since I had tasted only the inside of my mouth for three weeks, the white cranberry juice was electrifying. I ate raspberry JELL-O in a blaze of magnificent relief. With what I now attribute to the cephalic phase the world became slightly more bearable. Then, after two months on TPN and a clear liquid diet, the home care nurse pulled the PICC. I can’t remember exactly why this decision was made, because at the time I didn’t care. I was going to be a full-time eater again. Even though I went slow, everything was a feast. 

Erica and I drove to her parents’ house in Southern California for Thanksgiving. I ate the turkey dinner cautiously as if it was still alive. Even then, Erica had to drive the whole seven hours back to San Francisco because I felt the familiar spasms of pain and gurgles of food going into my bladder. At the hospital, they decided the fistula likely wouldn’t close on its own. I was scheduled for surgery two days after Christmas. 

And so, after only three weeks without TPN, eating was out, and the PICC went back in. It was placed by two nurses who encouraged me to relax while saying things like, “Is that in? No, that doesn’t look right.” 

Well, you’re no Stan, I thought. 

Rory came to visit me in the hospital one night. “Did you know they make 3D puzzles?” he asked, passing Erica a cheeseburger that she took outside. When a nurse came in with medications on a tray decorated with red gingham, Rory stopped talking and stared. “The world is so twisted sometimes,” he said after the nurse left, laughing and shaking his head. “Who do they think they are bringing your drugs in on a French fry tray?” I’d considered this question myself hundreds of times. After Rory and Erica left that night, with the darkness outside swallowing my tiny hospital room, I opened my laptop and watched a show where hunters in Montana cooked deer ribs on a campfire.

At Christmas, Erica’s family came to San Francisco because it would’ve been impossible for me to travel. They cooked Swedish and Korean food —traditions from both sides of Erica’s family. I chose to walk our dog. 

Humans diverge from animals when it comes to our social and cultural meaning behind food. As Sue McLaughlin, one of the authors of The Meaning of Food, said, “Like all animals, we eat to survive. But as humans, we transform simple feeding into the ritual art of dining, creating customs and rites that turn out to be as crucial to our well-being as are proteins and carbohydrates.”

In addition to sensory deprivation, not eating is social deprivation. In a survey of 51 patients on enteral nutrition, most patients complained that they were socially isolated and experienced a loss of identity. What you cook, how you cook for others, and when you eat provide structure to your days and a sense of self. Food is a form of communication. Without it, you are adrift and missing a functional language. 

They mostly use qualitative surveys to study the impacts of nutritional therapy on patient quality of life. Even if the physiological need for food is met, there is undeniably a physical and psychological effect for patients on TPN. Up to half of patients report being constantly tired; up to one-third have anxiety; one quarter are clinically depressed. 

I recently found a note on my computer titled “Food to Eat,” that listed what I was craving when I was on TPN: black pepper crabs, pecan waffles, meat pies, Turkish delight, and, of course, roast chicken. I have no memory of how I came to want these particular foods. Instead, I remember all the ways my body told me something was wrong. But the hunger, the sense of loss, and the search for connection in cooking shows were a perfectly normal response, as it turns out. Maybe as close to the human experience as you can get. 

After the surgery, I woke up in a room on the hospital’s fifth floor that looked over the city’s tallest building, the newly built Salesforce Tower. Erica bounced as she told me the surgeon had performed a masterful operation. He removed only six inches of bowel and fixed the bladder. The surgery rescued me from any more TPN in the immediate future while nudging me ever so slightly closer to a future without food—again, relief and suffering at the same time. 

My surgeon came in late one evening. “I hate that thing,” he said, nodding toward the Salesforce Tower out the window. “It looks like a giant penis.” 

“Really?” I said. “I think it looks like a burrito.”

Andrew Chapman is a science and medicine writer based in Truckee, California. His work has appeared in Scientific American, Hakai Magazine, and Eos, amongst others.

Editor: Carolyn Wells
Fact-checker: Julie Schwietert Collazo
Copyeditor: Krista Stevens