Researchers followed nearly 2,600 people with inflammatory bowel disease (IBD) for over 4 years to understand what triggers flare-ups—those painful periods when symptoms get worse. They found that a blood marker called calprotectin was the strongest predictor of flare-ups. Interestingly, for people with ulcerative colitis specifically, eating more meat was linked to a higher chance of experiencing flare-ups. However, other foods like processed items and fiber didn’t show clear connections to flare-ups. This research suggests that diet might play a role in managing IBD, but the effect varies depending on the type of disease and individual factors.

The Quick Take

  • What they studied: Whether what people eat affects how often their inflammatory bowel disease gets worse (flares up)
  • Who participated: 2,629 people with inflammatory bowel disease from 47 hospitals across the UK who were feeling well at the start. About half had Crohn’s disease and half had ulcerative colitis. They were tracked for an average of 4 years.
  • Key finding: A blood test marker called calprotectin was the strongest sign that a flare-up would happen. For people with ulcerative colitis, eating more meat was connected to more flare-ups—those eating the most meat had nearly twice the risk compared to those eating the least.
  • What it means for you: If you have ulcerative colitis, reducing meat intake might help prevent flare-ups, though this needs more research. A simple blood test can help predict your flare risk. This doesn’t mean everyone should avoid meat, but it’s worth discussing with your doctor, especially if you have frequent flare-ups.

The Research Details

This was a prospective cohort study, which means researchers followed the same group of people forward in time to see what happened. Participants filled out detailed food questionnaires at the beginning to record what they normally ate. Researchers then tracked them monthly for over 4 years, asking about symptoms and collecting blood and stool samples to measure inflammation markers.

The study included people from 47 different hospitals across the UK, making it representative of real-world IBD patients. Participants had to be in remission (feeling well) when they started, so researchers could track when they got worse. The study measured two types of flare-ups: ones patients reported themselves and ones confirmed by blood tests and stool samples showing inflammation.

This research approach is strong because it follows real patients over a long time period, which helps show what actually happens in daily life rather than in a controlled lab setting. By measuring both what patients felt and objective markers of inflammation, the researchers could confirm that flare-ups were real and not just perception. The large number of participants and long follow-up period make the findings more reliable.

This study is well-designed with a large number of participants followed for several years, which strengthens confidence in the findings. The researchers adjusted their analysis for many other factors that could affect results, like age, medications, and baseline inflammation levels. However, the study relied on people remembering what they ate, which can be imperfect. The findings about meat and ulcerative colitis are interesting but need confirmation in other studies before making major dietary changes.

What the Results Show

The strongest predictor of flare-ups was a blood marker called calprotectin measured at the start of the study. People with high calprotectin levels (250 or higher) were more than three times as likely to have objective flare-ups compared to those with low levels. This suggests that inflammation already present in the gut predicts future problems.

For people with ulcerative colitis specifically, meat intake showed a clear connection to flare risk. Those eating the most meat had about twice the risk of flare-ups compared to those eating the least. This relationship was strongest for objective flare-ups confirmed by blood tests and stool samples.

Interestingly, other foods didn’t show consistent relationships with flare-ups. Ultraprocessed foods, fiber intake, and polyunsaturated fatty acids (healthy fats) didn’t clearly predict whether someone would have a flare-up. This suggests that diet’s effect on IBD may be specific to certain foods and certain types of disease.

The study found that the meat-flare connection appeared stronger in ulcerative colitis than in Crohn’s disease, suggesting different disease types may respond differently to diet. The baseline calprotectin level was such a strong predictor that it may be useful as a tool to identify high-risk patients who need closer monitoring or more aggressive treatment. The long follow-up period (average 4+ years) showed these patterns held up over time.

Previous research on diet and IBD has been limited and sometimes contradictory. This study is one of the largest and longest to specifically examine dietary factors in people already in remission. While some smaller studies suggested fiber might help, this large study didn’t find clear evidence for that. The finding about meat in ulcerative colitis is relatively new and adds to growing evidence that diet may matter more for some IBD types than others.

The study relied on people remembering what they ate at the beginning, which can be inaccurate. People’s diets also change over time, but the study only measured diet once at the start. The research was conducted in the UK, so results might differ in other countries with different foods and populations. While the study found associations between meat and flare-ups, it doesn’t prove that meat causes flare-ups—other factors could explain the connection. The study couldn’t determine the best amount of meat to eat or which types of meat matter most.

The Bottom Line

If you have ulcerative colitis with frequent flare-ups, discuss reducing meat intake with your gastroenterologist or dietitian (moderate confidence). Ask your doctor about checking calprotectin levels regularly, as high levels suggest increased flare risk (high confidence). Don’t make major dietary changes without professional guidance, as individual responses vary greatly (high confidence). For Crohn’s disease, the evidence for meat reduction is weaker, so discuss individually with your care team (low to moderate confidence).

This research is most relevant for people with ulcerative colitis who have frequent flare-ups or are looking for ways to prevent them. People with Crohn’s disease should discuss these findings with their doctor, as the meat connection wasn’t as clear in this group. Anyone with IBD should know about calprotectin testing as a way to predict flare risk. People newly diagnosed with IBD may benefit from understanding that diet might play a role in their disease management.

If you reduce meat intake, you might notice changes in flare frequency over weeks to months, though individual responses vary. Calprotectin levels can change over weeks to months, so regular testing (as recommended by your doctor) helps track trends. Major dietary changes typically take 2-3 months to show clear effects on IBD symptoms.

Want to Apply This Research?

  • Track daily meat intake (type and amount) alongside IBD symptoms and flare occurrences. Users can log servings of beef, pork, poultry, and processed meats separately to identify personal patterns. Compare meat intake in weeks before flare-ups versus symptom-free weeks.
  • Set a weekly meat intake goal based on discussions with your doctor (for example, reducing from 5 servings to 2-3 servings per week). Use the app to log meat-free meal ideas and track successful low-meat days. Create reminders for scheduled calprotectin blood tests to monitor inflammation markers.
  • Create a 12-week tracking period to establish your personal meat-symptom relationship. Generate monthly reports comparing meat intake patterns to flare frequency. Set alerts when calprotectin results are available and log them in the app to correlate with dietary patterns over time.

This research provides evidence that diet may influence IBD flare-ups, particularly meat intake in ulcerative colitis, but individual responses vary significantly. These findings should not replace medical advice from your gastroenterologist or IBD specialist. Before making major dietary changes, consult with your healthcare provider or a registered dietitian familiar with IBD. This study shows associations, not definitive cause-and-effect relationships. Calprotectin testing should only be ordered and interpreted by your medical team. If you experience severe symptoms or signs of a flare-up, seek immediate medical attention.