We know that with the festive season comes an onslaught of foods that are quite high in fat and sugar — typically significantly more so than your day-to-day diet. We wanted to find out exactly what happens when we
sabotage our diets go a little hog wild on Thanksgiving and throughout the holidays (eggnog, anyone?), so we consulted two experts on the body and its reaction to food: Lisa Eberly, RD, MPH, and Nicole Aurigemma, MS, physiologist at the Penn State Muscle Biology Lab.
Remember: balance is the key to a healthy life — one big meal isn't going to hurt you! But before you start digging into pie and potatoes with reckless abandon and no foresight, here's a rundown of exactly what goes on in your body during and postbinge. (Note: a binge is relative to everyone's personal eating habits and body, and doesn't necessarily have a quantified threshold. Both our sources described it as eating more food and more sugary and fatty foods than you would in a given meal.) Many of these symptoms can become more severe with consistent bingeing, less so if you're balancing your Thanksgiving feast with healthy habits.
Your Stomach Stretches
"Your stomach is very elastic . . . like yoga pants!" Eberly explained. "The exact size varies from person to person, but the average adult can hold about one litre (the size of a large burrito)." We like how she explains things.
"When eating a huge meal, the stomach can stretch up to four litres." (She noted it's like wearing a dress or pair of trousers that are two sizes too small.) But as mentioned, your stomach is elastic, and returns somewhat quickly to its one-litre state. This isn't the case if you keep bingeing. "However, when you overeat, particularly somewhat regularly, your stomach can stretch permanently," she said. "So, those who regularly eat past feeling full may have bigger stomachs than those who don't, leading them to need more food to feel full . . . a very vicious cycle."
And there are factors that can make this situation even worse. Eberly said, "When you drink soda or beer with dinner, those gases contribute air into this stomach and intestinal space, stuffing it further." Keep carbonated beverages to a minimum, and "try ginger tea."
Stomach Tissue Malfunctions
Eberly also told us that "the tissue at the opening of the stomach that tells the brain you're full can malfunction." This part of your body is called "an electrical conduit pathway." That pathway essentially "asks" your brain if your body is full and satiated. Within 20 minutes, the brain signals and lets you know that you're full. But if you overeat, "you risk this malfunctioning long-term, making it more difficult for your brain to recognise fullness."
Your Brain Has an Addiction-Like Response
Aurigemma noted that this "highly palatable food" can have interesting — and possibly dangerous — effects on the brain. "Overconsumption of these highly palatable foods can trigger neuroadaptive responses in the brain reward system, similar to those seen in addiction," so if you've ever wondered if sugar is actually a drug, here's your proof.
"The brain feels rewarded after eating comfort food, and overloading that reward sense can create an addictive and habitual cycle."
Let's look at how this works: when you eat regularly, you feel a normal sense of hunger when you need food. This is because the "hormone called ghrelin is increased before meals and stimulates appetite." Those same hormone levels "decrease after food is consumed." Then you feel full, and you can move on with your day. It's not the same during an overload of stuffing, mashed potatoes, gravy, pie, cocoa, eggnog, etc.
"With a high fat and sugar binge, the ghrelin remains elevated even after eating," Aurigemma said. This means that you don't feel as sated and your brain doesn't know when to stop.
Then there's the feeling of addiction, thanks to the release of dopamine. She explained that "on top of influencing appetite, ghrelin also activates the dopaminergic neural pathway involved in regulating reward and motivating behaviors; so by eating fatty and sugary foods, your ghrelin levels remain increased, which activates the dopaminergic pathway to release dopamine — you start to crave these highly palatable foods because these foods make you feel good due to the dopamine release. This leads to a pretty vicious cycle."
Eberly echoed this and painted a pretty, ah . . . vivid . . . picture, saying, "Imagine a turkey dinner is cocaine" (but wait, she keeps going). "If you have a tiny bit, you'll want more; however, the more you have, the more you'll want. The brain feels rewarded after eating comfort food, and overloading that reward sense can create an addictive and habitual cycle."
She noted that it's important to remember that one big meal isn't going to throw you off course, but "overeating regularly over the holiday months is where you run into trouble." The dangerous territory is when you feel like you can't "quit" food, because our bodies are "naturally hardwired to seek high-calorie foods (thanks, evolution)." She encourages us to balance sugary carbohydrates and fat with protein and greens to keep ourselves in check.
Hormones Are Released, Fat Is Stored
While ghrelin stimulates appetite, other hormones keep it in check and stimulate a full sensation . . . but this process can take up to 20 minutes, so if you're eating quickly and ravenously, "you may eat far past fullness before your brain gets the memo," said Eberly.
"Oxyntomodulin and Peptide Tyrosine Tyrosine (also known as PYY)" are the satiety hormones that make you feel full, Eberly told us. "They're secreted by the intestines when you eat a high-calorie meal, and when this reaches the brain, it tells you that you're full," she said. "Additionally, a hormone called leptin tells the brain how much energy you currently have, and how much food you need — kind of like a bank account living paycheck to paycheck." This hormone also triggers your brain to stop eating, and as Eberly put it, says to your brain, "Bro . . . bro . . . put the fork down."
"Overconsumption of these foods can trigger responses in the brain, similar to those seen in addiction."
Because you've consumed more energy than your body needs (unless you're running a marathon after your holiday meal), "the metabolic chemical reactions that process food work overtime to metabolise all that food," Eberly said. "It gets stored as fat rather than being converted to energy . . . I know this one seems obvious, but yes, overeating equals extra fat."
"This is particularly true with foods that contain high-fructose corn syrup," said Aurigemma, "which has been shown to increase fat accumulation." She noted that upping your carb intake drastically can lead to "the increase in expression of genes involved in de novo lipogenesis, which essentially is the conversion of dietary carbohydrates to fat, which is then stored within the body." What does that mean? "Simply put, the more sugar and carbs you eat, the more will be stored as fat if you aren't active."
Both Aurigemma and Eberly suggested adding some movement to your holiday season, and Eberly in particular said, "Drinking a full glass of water before and after eating and going for a 20-minute walk immediately after eating your big meal can remedy this."
Your Blood Sugar Goes on a Wild Ride
When you binge, "the pancreas produces extra insulin to process the sugar load from the carbohydrates and remove it from the blood," said Eberly. And it doesn't stop there. "Your body will produce insulin until your brain learns that the sugar levels in the blood are safe."
"But hormones don't move as fast as we think they do," she said. By the time your brain gets the memo that your blood sugar is normal again, your levels are often too low and below the healthy threshold. "This leads to exhaustion, dizziness, nausea, and even depressive symptoms."
"These symptoms often make us want to eat more food, particularly carbs."
And big surprise: "These symptoms often make us want to eat more food, particularly carbs," she told us. Her suggestion again was to go on a 20-minute walk after your meal.
You Might Have Heartburn
"[Your] stomach makes hydrochloric acid to break down food," said Lisa. "More food, more acid to irritate lining of stomach and creep into oesophagus." This is what leads to a burning sensation and discomfort. Her suggestion to mitigate the pain? "Try a teaspoon of baking soda mixed with a shot glass of water."
Your Eating and Sleeping Patterns Are Thrown Off
Eberly told us that the circadian rhythm, which controls when you want to sleep and when you want to eat, will be thrown off. "If you overeat, that clock can shift and actually make you want to eat more." So not only will you be ravenous for that meal or two, but "you could even wake up hungry in the middle of the night, or feel extra hungry the next morning, leading to eating even more."
"It also disturbs sleep patterns," Eberly said, "leading to less restful sleep, which can lead to being tired and cranky, which almost always leads to pizza. Again with this vicious cycle! Ensuring you get back on your regular eating pattern next day will help."
You Become Exhausted
"Your parasympathetic nervous system kicks in," said Eberly. Blood rushes to the the small intestine to aid in digestion of the extra food. "This puts your body in a state of lethargy, and this, combined with the insulin response, is why we basically crawl to the couch after heavy holiday meals."
One day of indulgence or one big meal won't ruin your life or totally derail you — keep that in mind! Aurigemma noted that the key is to ensure that "it doesn't happen on the regular," so if you're allowing yourself to let loose a little for a big meal, then go for it!
If you did go overboard or are nervous about self-control, here are some tips.
From Aurigemma: "Remain active during this time — keep exercising (maybe sign up for a Thanksgiving turkey trot as a way to spend time with family and keep active). Don't 'save' your calories for a big meal. And moderation is key."
From Eberly: "During your meal, try putting your fork down between bites, and eat slowly. Go on a 20-minute walk after your meal, let yourself relax on the couch afterward to let [the digestion] process happen, get back to a regular eating schedule, and try ginger tea."