Millions of Americans have struggled to deal with the side effects of new weight loss treatments, but experts believe what’s on your plate can make a world of difference.
Approximately 26 million American adults have used a GLP-1 drug like Ozempic or Mounjaro, with about 13 million currently taking one. Common side effects include nausea and gastrointestinal issues, while rare complications can include pancreatitis.
Greasy, fried foods like fries, pizza and buttery sauces can dramatically slow down digestion, causing constipation. Processed snacks like chips and crackers often lack fiber and can destabilize blood sugar levels.
And foods with a spicy kick can inflame the stomach lining and worsen existing heartburn from GLP-1s.
GLP-1s work by mimicking the GLP-1 hormone that helps regulate blood sugar, and one of its key effects is to significantly slow down the rate at which the stomach empties its contents into the intestines.
While this delayed digestion promotes lasting fullness, a key benefit for weight loss, it also means difficult-to-digest, fatty foods linger longer, leading to discomfort.
For some, this slowdown causes constipation. For others, the system reacts in the opposite way, triggering bouts of diarrhea to clear the backlog.
Now, Daily Mail has spoken to experts about the foods most likely to spark uncomfortable side effects.
High-fat meals like fries, pizza, and burgers are especially problematic for patients on GLP-1 drugs like Ozempic or Mounjaro (stock)
Fries, pizza and burgers
Marlee Bruno, a certified physician associate who prescribes GLP-1s, told the Daily Mail: ‘This medication is not a magic wand, so the biggest mistake I see is people eating the same way they did before starting the medication.’
High-fat foods like fries, pizza and cheeseburgers are particularly troublesome for people taking a GLP-1.
When someone eats a large, high-fat meal, they consume food that is inherently slow to digest because of its fat content.
GLP-1s prolong the already-lengthy process of breaking down fats from burgers, pizza and other fatty foods.
The medication does this by trapping food in the stomach for an uncomfortably long time and directly causes nausea, vomiting, abdominal pain and bloating.
Bruno added: ‘Large portions make this so much worse, especially when people skip meals all day and then eat one big dinner.’
Spicy snacks and sauces
The capsaicin in spicy foods irritates a digestive tract made extra-sensitive by GLP-1 drugs, triggering severe heartburn, nausea and cramps (stock)
Dr Holly Wyatt, an endocrinologist and nutrition professor at the University of Alabama Birmingham, told the Daily Mail: ‘Spicy or very acidic foods can also aggravate symptoms for some people, especially early in treatment or during dose increases.’
Spicy foods contain capsaicin, a compound that directly stimulates pain receptors in the digestive tract. While taking GLP-1s, the stomach and intestines are already more sensitive because of slowed gastric emptying.
Capsaicin can irritate the esophageal lining and stomach, triggering or worsening heartburn and nausea. It may lead to inflammation or spasms in the intestines, causing abdominal cramping.
Because GLP-1s slow down stomach emptying, spicy foods sit in the stomach for a prolonged period, intensifying irritation that leads to more severe and persistent heartburn or stomach pain.
Capsaicin, which gives chili peppers their heat, can also accelerate gut motility, or the natural movement of food through the intestines.
The compound’s stimulating effect directly clashes with the drug’s own slowing influence on the digestive system, leading to unpredictable and urgent bowel habits, ranging from sudden diarrhea to painful cramping.
Frequent diarrhea also poses a serious risk of dehydration, a particular concern for patients on these medications because GLP-1 medications can unintentionally blunt thirst signals.
Cakes and cookies
The high fat in sugary treats like cakes and cookies digests very slowly, lingering for hours in a medication-slowed gut and worsening nausea, bloating and reflux (stock)
Indulging in cakes, cookies, and other sugary, highly refined carbohydrates can worsen the most common GLP-1 side effects.
Consuming high-sugar foods works against the drug’s purpose of stabilizing blood sugar and promoting satiety, potentially leading to rebound hunger and cravings as blood sugar levels plummet after the initial spike.
These foods cause a rapid, high spike in blood glucose, prompting the body to release large amounts of insulin to compensate.
While GLP-1 agonists like Ozempic are designed to improve the body’s insulin response, a sudden, massive sugar load can overwhelm this regulated system.
This mismatch can trigger or intensify feelings of nausea, dizziness and a general ‘sugar crash’ feeling, often more severe and prolonged than one would experience off the medication.
The simple sugars can begin to ferment or draw water into the stomach, leading to increased bloating, gas and abdominal distension. This stagnant, sugary content can also promote acid reflux and indigestion.
Fat is the macronutrient that is digested the slowest. In a gut already slowed by medication, a high-fat treat like a frosted cupcake or cookie can sit in the stomach for hours, leading to nausea, bloating, cramping and reflux.
Wheat and dairy can also trigger individual sensitivities, even in someone who does not have a diagnosed allergy like celiac disease, causing bloating, gas and altered bowel habits.
Sodas and cocktails
Mixing alcohol with GLP-1 drugs is dangerous and strongly discouraged. It can trigger a severe, delayed blood sugar crash, a medical emergency that can occur hours later, even during sleep (stock)
Soda is essentially liquid sugar, causing the same rapid and high spike in blood glucose that eating a cupcake would, leading to the same nausea, dizziness and a subsequent crash.
The carbon dioxide bubbles in soda create gas and pressure in the stomach, where digestion is already significantly slowed by the medication.
This can lead to immediate and uncomfortable bloating, distension and worsened reflux or heartburn as the gas has nowhere to go.
Dr Holly Wyatt told the Daily Mail that carbonated beverages and alcohol typically intensify bloating, reflux and nausea
Wyatt told the Daily Mail: ‘Carbonated drinks and alcohol commonly make bloating, reflux, and nausea worse.’
Alcohol is strongly discouraged and can be particularly dangerous for individuals taking GLP-1 medications.
Because the drugs slow stomach emptying, alcohol is absorbed into the bloodstream more slowly and over a longer period. This can delay the feeling of intoxication, leading someone to drink more than they normally would.
More critically, mixing the medication with alcohol can cause a dangerous, delayed crash in blood sugar, a serious medical emergency that can strike hours later, even during sleep.
Alcohol is also a gastric irritant. In a sensitive digestive system slowed by the medication, it can dramatically worsen nausea, vomiting, abdominal pain and acid reflux.
The general and strong medical recommendation is to avoid alcohol entirely while taking GLP-1 medications.
Ultra-processed foods
Ultra-processed foods like chips and sugary cereal lack the fiber required for a slowed digestive system (stock)
Packaged snacks, sugary cereals, mass-produced breads and other ultra-processed foods lack the fiber to support the slowed digestion and instead provide a surge of sugar and empty calories that can spike nausea, worsen bloating and intensify constipation.
Without fiber to slow down sugar absorption for better blood sugar control, these foods are quickly broken down into simple sugars.
This creates a conflict in the slowed system. Sugars spike blood sugar rapidly while food lingers, triggering nausea, dizziness and a sugar crash-like malaise.
UPFs provide very little fullness per calorie, leading someone to eat handfuls of chips or a pile of chicken nuggets before they begin to feel satisfied.
This large volume of empty calories sitting in a slowed stomach is a direct recipe for bloating, distension and indigestion.
A diet full of processed foods that are low in fiber exacerbates constipation by failing to add the necessary bulk to stimulate bowel movements, leading to more severe and uncomfortable constipation.
Their poor nutritional profile can lead to rebound hunger and cravings, making it harder to adhere to a healthy diet and achieve treatment goals.
