Patients ask me this all the time: "Doc, what do YOU avoid?"
The honest answer is yes, I limit some foods. But not for the reasons you might think.
I'm not counting calories. I'm watching what happens after food enters the digestive tract. Gas. Reflux. Urgency. Bloating. Those are the signals I pay attention to, and they tell me a lot more than a nutrition label does.
Here's the part that surprises people: the "healthy" swap is sometimes the problem. Sugar-free can mean symptom-full.
1. Sugar Alcohols: The Hidden Cause of Bloating for Many People
Sorbitol, maltitol, xylitol, erythritol. If you don't recognize the names, you've almost certainly eaten them. They hide in sugar-free gum, sugar-free candy, and a lot of protein bars.
Here's what most people don't realize. Most sugar alcohols are only slowly and partly absorbed in the small intestine. So they keep moving, and when they reach the colon, gut microbes ferment them. A systematic review of 79 studies found this malabsorption rises with the dose, and gets worse when several are eaten together.
The result? Gas, bloating, and for some people, diarrhea. Sugar alcohols can also pull water into the intestine, which is part of why a few pieces of sugar-free candy can send someone running.
One exception worth knowing: erythritol. It's a smaller molecule, and most of it is absorbed before it reaches the colon, so it usually causes fewer symptoms than sorbitol or maltitol.
If you chew gum all day or eat a protein bar every afternoon and wonder why you're bloated by dinner, start by reading the label.
2. Ultra-Processed Foods
Think about the foods with long ingredient lists: additives, emulsifiers, refined oils, and ingredients you'd never keep in your own kitchen.
Research suggests that diets heavy in these foods may be associated with changes in the gut microbiome and intestinal inflammation. In a study of more than 116,000 adults across 21 countries, people who ate the most ultra-processed food had a higher risk of developing inflammatory bowel disease. A 2024 review covering nearly 10 million people linked higher intake with a range of health problems, including gastrointestinal ones.
Some of the concern centers on emulsifiers. In lab models, several common emulsifiers changed human gut bacteria in ways expected to promote inflammation. A small 2025 human trial found emulsifiers lowered short-chain fatty acids, helpful compounds made by gut bacteria, though it didn't see a change in inflammation over two weeks. These are associations and early findings, not final proof.
I want to be clear about something. It's not one ingredient. It's the cumulative effect, day after day. One packaged snack isn't the issue. A diet built on them might be.
3. Energy Drinks and Sweetened Coffee Drinks
People obsess over what's on their plate and forget what's in their cup.
Look at what's in a typical energy drink: caffeine, carbonation, artificial sweeteners, and sugar, all in one can. For a sensitive gut, that combination is a recipe for reflux, irritation, and urgency.
In a study that followed more than 48,000 women, those who drank more coffee, tea, and soda had a higher risk of reflux symptoms. Swapping those drinks for water was linked to a lower risk. The evidence on carbonation alone is more mixed, which is one more reason to look at the whole drink, not one ingredient.
Let me say this plainly. Coffee isn't the villain. In that same study, the extra risk from coffee was modest. A plain cup of coffee is a very different thing from a large, sweetened drink topped with whipped cream. A beverage that resembles dessert might be the real problem.
4. Processed Meats
Deli meats are convenient. I get it. But they carry preservatives, sodium, nitrates, and nitrites.
Higher consumption of processed meats has been associated with increased risk of several chronic diseases. The World Health Organization’s cancer agency classifies processed meat as carcinogenic to humans, based mainly on its link to colorectal cancer. Its experts estimated that each 50 gram portion eaten daily raises colorectal cancer risk by 18%.
That's why I think about food quality, not just macronutrients. A sandwich can hit your protein goal and still not be doing your body any favors.
5. Seed Oils, but Not for the Reason the Internet Says
You've probably seen the claims online. Here's my take.
A little sunflower or canola oil won't suddenly damage your gut. That's not the concern. The American Heart Association has supported omega-6 fats, the main fat in these oils, as part of a heart-healthy diet.
The real issue is where these oils show up: fried foods, packaged snacks, and frozen meals. If you're eating a lot of seed oils, you're probably eating a lot of ultra-processed food. That's the pattern that matters.
This Isn't a List of Bad Foods
I want to step back for a second. This is not a list of foods you should fear. It's a list of foods that explain how digestion works.
So here's the shift I'd ask you to make.
Stop asking: Which foods should I cut out?
Start asking: Which mechanism is causing my symptoms?
Most digestive symptoms come down to a handful of things:
- Poor absorption. Something isn't being taken up where it should be.
- Excess fermentation. Gut microbes turn leftovers into gas.
- Osmotic effects. Water gets pulled into the intestine.
- Irritation of the digestive tract.
- A diet dominated by ultra-processed foods.
When you understand the mechanism, you don't have to guess. You can make a small change, watch what happens, and learn from it.
Your Gut Is Giving You Information
Your gut is constantly telling you something. The goal isn't to fear food. It's to learn how your body responds.
If symptoms are frequent, severe, or getting worse, talk with your healthcare provider. Understanding how digestion works helps you ask better questions, have better conversations with your healthcare provider, and make more informed decisions about what you eat.
That's what Regarding Your Gut is all about.
