Weight Loss and Gas: Are They Linked?
Health ConditionsDigestive HealthExcessive Gas

4 Reasons You’re Feeling Gassy While Losing Weight, and How to Fix It

Eating more fiber than you’re used to can cause tummy troubles and gas.
4 Reasons You’re Feeling Gassy While Losing Weight, and How to Fix It
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Updated on August 6, 2025
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You’ve made changes to your diet to ramp up your weight loss, and now you’re noticing an unwelcome, gassy side effect. Sound familiar?

Our guts can be finicky, so when you start tinkering with your diet, they’re one of the first parts of the body to respond — often by way of gas, in the form of bloating and flatulence.

Being gassy isn’t always a sign that something bad’s happening, by the way. It’s possible that you’re having gas because you’ve added more healthy foods to your diet and your body just needs some time to adjust. If your gas is particularly persistent or is causing you pain, though, you should see your doctor.

If you’re hoping to get to the bottom of all that bloat, here are four reasons that your weight loss diet may be making you gassy, and what you can do to find gas relief.

1. You’re Eating More So-Called ‘Diet’ Foods

If you’re stocking up on more “no sugar added” or “sugar-free” foods as part of your weight loss plan, an intolerance to sugar alcohols could be the cause of your gas troubles.

Sugar alcohols, also called polyols, are common in diet-type foods like diet soda, light yogurt, and sugar-free snack bars, because sugar alcohols don’t contain as many calories as regular sugar.

The trouble is, the body can’t digest sugar alcohols, so when they make their way to the colon (large intestine), the gut bacteria there break them down, causing gas, bloating, and sometimes diarrhea.

Certain fruits and vegetables, like plums and mushrooms, naturally contain sugar alcohols, which can cause gas and other gastrointestinal issues in some individuals.

Fix It

Limit your intake of foods containing sugar alcohols, and if the problem persists, try skipping them altogether. Aside from wreaking havoc on your gut, these types of foods are typically highly processed and contain other unwanted additives.

 Stick to whole foods as much as possible, and if you’re going to enjoy something sweet, go for the real thing — just enjoy a smaller portion.

When you’re reading food labels, look out for ingredients that end in “ol,” like xylitol and sorbitol. More often than not, these are sugar alcohols.

2. You’re Eating More Fiber

Eating foods rich in fiber is a smart play when trying to lose weight. A high-fiber diet may keep you feeling fuller longer, and eating more nutrient-rich, high-fiber foods (fruits, veggies, whole grains, beans, nuts, and seeds) means you’re likely eating fewer of the less nutritious options.

But most of us aren’t eating enough fiber. On average, we get about 16 grams per day, yet the Dietary Guidelines for Americans recommend between 28 and 34.

Because we run at such a deficit, this often means we’re adding more high-fiber foods to our diet when we’re trying to lose weight or following a weight loss plan — and that can take some getting used to.

Our bodies don’t digest fiber until it reaches the large intestine, where the bacteria in the gut breaks it down for food via fermentation. Fermenting means bubbles, which is why you may get gassy when eating more fibrous foods than you normally do.

Fix It

The answer isn’t to avoid eating more fiber, but rather to add fiber-rich foods into your diet at a more gradual pace. Start with an extra piece of fruit each day or an extra serving of vegetables. Add half a cup of beans to your dinner, and increase as tolerated. Your body should adjust over time.

3. You’re Sipping Carbonated Drinks

Many diet plans encourage drinking more water and less juice and other sweetened beverages. This is a good thing. But water can get boring for some people, and oftentimes we look for alternatives to help soothe our cravings, turning to diet soda and other low-calorie carbonated beverages.

Carbonated beverages contain bubbles, which means when you drink them, you’re putting more air into your gut. Trapped air causes gas. If you’re drinking your diet soda or sparkling water with a straw, you’re likely swallowing even more air.

Fix It

If you think carbonated drinks are the culprit, assess how much you’re drinking and begin to cut down. You may need to eliminate them altogether. If you’re missing out on flavor, try drinking plain water infused with whole fruit instead.

4. You’re Eating More Raffinose

Raffi-what? Raffinose is an oligosaccharide — a type of sugar found in some vegetables, like broccoli, Brussels sprouts, and cabbage, as well as in whole grains and beans. Raffinose isn’t something you should avoid — it’s common in plenty of good-for-you foods — but know that it may upset your stomach, especially if you’re eating it in large quantities.

Like fiber, raffinose bypasses your small intestine — virtually untouched — and isn’t broken down until it reaches your colon, where bacteria get to work. The digestion process there releases hydrogen, carbon dioxide, and, for about 30 percent of people, methane gas, all of which are released through flatulence.

Fix It

Increase your intake of these foods slowly, especially if you find you’re sensitive to them. You can also try alpha-galactosidase, an over-the-counter medication, which is an enzyme that will help your body digest raffinose and other complex carbohydrates.

The Takeaway

  • If you’re feeling gassy while trying to lose weight, it might be due to adding more fiber-rich foods to your diet.
  • Some “diet” foods contain sugar alcohols that can cause bloating and gas because they are not easily digested. Consider reducing or eliminating these to minimize discomfort.
  • If you drink a lot of carbonated beverages, know that they can trap air in your digestive system, leading to increased gas.
  • Foods high in raffinose, such as certain vegetables and beans, may cause gas issues for some people. If you want to increase your intake of these foods, do so slowly or consider using over-the-counter enzymes to help with digestion.
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. Facts About Sugar and Sugar Substitutes. Johns Hopkins Medicine.
  2. What Are the Polyols? Monash University. April 17, 2016.
  3. Why Is Fiber So Important? Cleveland Clinic. May 1, 2025.
  4. Dietary Guidelines for Americans 2020-2025. U.S. Department of Agriculture. December 2020.
  5. Eat More Fiber-Rich Foods to Foster Heart Health. Harvard Health Publishing. February 5, 2024.
  6. Fu J et al. Dietary Fiber Intake and Gut Microbiota in Human Health. Microorganisms. December 18, 2022.
  7. Dietary Fiber: Essential for a Healthy Diet. Mayo Clinic. December 11, 2024.
  8. Zero Weight Loss From Zero Calorie Drinks? Say It Ain’t So. Harvard Health Publishing. March 22, 2021.
  9. Is Sparkling Water Good For You? Benefits and Risks. The University of Chicago Medicine. May 10, 2023.
  10. Gas in the Digestive Tract. Johns Hopkins Medicine.
  11. Gas and Gas Pains: Diagnosis and Treatment. Mayo Clinic. January 6, 2022.
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Waseem Ahmed, MD

Medical Reviewer

Waseem Ahmed, MD, is an assistant professor of medicine in the Karsh Division of Gastroenterology and Hepatology at Cedars-Sinai Medical Center in Los Angeles and serves as Director, Advanced Inflammatory Bowel Disease Fellowship and Education within the F. Widjaja Inflammatory Bowel Disease Institute.

He received his undergraduate degree from the University of Michigan and attended medical school at Indiana University. He then completed an internal medicine residency at New York University, followed by a fellowship in gastroenterology and hepatology at Indiana University, and an advanced fellowship in inflammatory bowel disease at the Jill Roberts Center for Inflammatory Bowel Disease at New York-Presbyterian Hospital/Weill Cornell Medicine. Prior to his current role, Dr. Ahmed served as an assistant professor of medicine within the Crohn’s and Colitis Center at the University of Colorado from 2021-2024.

Dr. Ahmed is passionate about providing innovative, comprehensive, and compassionate care for all patients with inflammatory bowel disease (IBD). His research interests include IBD medical education for patients, providers, and trainees; clinical trials; acute severe ulcerative colitis; and the use of combined advanced targeted therapy in high-risk IBD.

He enjoys spending time with his wife and dog, is an avid follower of professional tennis, and enjoys fine dining.

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