What Causes Stomach Bloating While Dieting?
Health ConditionsDigestive Health

Stomach Bloating When Your Diet Changes: Why You Have It and How to Fix It

Stomach Bloating When Your Diet Changes: Why You Have It and How to Fix It
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Updated on July 31, 2025
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Bloating soon after you make changes to your diet is common, as are other gastrointestinal issues like gas, constipation, and diarrhea. When you alter what you’re regularly eating and drinking, your body may need some time to adjust. There are ways, though, to help stop the bloat.

Why Starting a Diet Causes Bloating

Bloating is the feeling of your belly being full and tight.

 It’s often due to gas, but it can be caused by overeating, eating gas-producing foods, and constipation. Common gas-producing foods include beans, whole grains, some fruits and vegetables, onions, dairy products, and leafy greens — many things that are part of a balanced, nutritious diet.

Diet changes can also contribute to constipation, which also can cause bloating. “For example, if someone is not used to eating high-fiber foods and suddenly switches to a diet full of salads and vegetables, they are very likely to experience at least transient bloating,” says Jesse P. Houghton, MD, senior medical director of gastroenterology at the Southern Ohio Medical Center in Portsmouth, Ohio.

Switching to a low-carb diet can have the same effect, he says.

The specific causes of bloating will depend on your diet and what new things you have introduced or removed from your regular rotation.

Other Causes of Bloating

Another potential source of bloating is a group of carbohydrates known as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols).

FODMAPs are found in foods such as wheat, onions, garlic, soy milk, most legumes, apples, pears, and plums.

 You can try eliminating individual ingredients to see if it resolves the problem — or commit to a fully low-FODMAP diet. Remember, a low-FODMAP diet is only meant to be temporary, and you should eventually reintroduce those foods back into your diet.

However, it can be difficult to transition to a low-FODMAP diet without assistance, given how restrictive the diet is. Working with a registered dietitian can help.

Bloating can also be caused by certain medical conditions, including gastroesophageal reflux disease, irritable bowel syndrome, Crohn’s disease, and urgent medical issues such as a bowel blockage or certain cancers.

 However, temporary bloating is typically not a sign of anything serious.

How to Prevent Bloating

If possible, slowly tweaking your diet over time, rather than overhauling your eating habits overnight, can help you avoid unpleasant bloating. Other strategies can help too.

Try the following:

  • Stay hydrated. Staying properly hydrated can help. Dehydration can lead to constipation, which can exacerbate the feeling of bloating.

  • Avoid chewing gum. You swallow air when you chew gum, and the air then gets trapped in the digestive system, which can contribute to bloating.

  • Try over-the-counter medications for bloating. Ask your doctor which one might be best for you. They may recommend simethicone (Gas-X).

  • Avoid or limit high-fat foods, carbonated drinks, and high-sugar foods. Talk to your doctor about which foods to limit or avoid. The same foods don’t always cause bloating for everyone.

If symptoms of bloating, gas, constipation, or diarrhea are persistent or interfering with your everyday life, talk to your doctor about getting checked for food allergies or intolerances (such as lactose intolerance or celiac disease). However, if you experience temporary bloating related to a diet change, the symptoms should dissipate as your digestive system adjusts to your new way of eating.

The Takeaway

  • Bloating after changing to a new diet is common, and it’s usually not a cause for concern. High-fiber foods, which are part of a healthy diet, can contribute to bloating — especially if you start eating a lot more of them than you previously did.
  • Staying hydrated, avoiding chewing gum, skipping carbonated beverages, and avoiding other trigger foods can all help prevent bloating.
  • If bloating is persistent or interfering with your daily activities, talk to your doctor. Allergies, intolerances, and certain diseases can also sometimes be the underlying cause of frequent bloating.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Bloating: Causes and Prevention Tips. Johns Hopkins Medicine.
  2. Low FODMAP Diet Introduction. University of Michigan Health.
  3. High and Low FODMAP Foods. Monash University.
  4. Oller B. Bloating. American Academy of Pediatrics. July 2024.
  5. How to Beat the Bloat. Northwestern Medicine. May 2025.
  6. Eating, Diet, and Nutrition for Gas in the Digestive Tract. National Institute of Diabetes and Digestive and Kidney Diseases. June 2021.
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Yuying Luo, MD

Medical Reviewer

Yuying Luo, MD, is an assistant professor of medicine at Mount Sinai West and Morningside in New York City. She aims to deliver evidence-based, patient-centered, and holistic care for her patients.

Her clinical and research focus includes patients with disorders of gut-brain interaction such as irritable bowel syndrome and functional dyspepsia; patients with lower gastrointestinal motility (constipation) disorders and defecatory and anorectal disorders (such as dyssynergic defecation); and women’s gastrointestinal health.

She graduated from Harvard with a bachelor's degree in molecular and cellular biology and received her MD from the NYU Grossman School of Medicine. She completed her residency in internal medicine at the Icahn School of Medicine at Mount Sinai, where she was also chief resident. She completed her gastroenterology fellowship at Mount Sinai Hospital and was also chief fellow.

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Nina Bahadur

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Nina is a writer and editor with a focus on health and culture. She loves pilates, skiing, and her rescue dog.

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