Stomach Bloating While Dieting: Why You Have It and How to Fix It

Bloating at the beginning of a 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 bloating.

Read more: The 9 Worst Foods for Bloating

Johns Hopkins Medicine describes bloating as when "your belly feels full and tight, often due to gas." This 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, the senior medical director of gastroenterology at the Southern Ohio Medical Center in Portsmouth, Ohio.

"On the flip side, say a person starts on a low-carb diet. … This often involves restricting fruits and vegetables, which can lead to new-onset constipation. This in turn can cause gas and flatus to build up in the intestines, thus causing bloating," Dr. Houghton says.

The specific causes of bloating will depend on what your diet had been like and what new things you have introduced or removed from your regular meal plan.

According to Michigan Medicine, another potential source of bloating is a group of carbohydrates known as FODMAPs (this stands for "fermentable oligosaccharides, disaccharides, monosaccharides, and polyols").

FODMAPs are found in foods including wheat, onions, garlic, soy milk, most legumes, apples, pears and plums, according to researchers at Monash University in Melbourne, Australia. You can try eliminating individual ingredients to see if that resolves the problem, or commit to a fully low-FODMAP diet.

However, Michigan Medicine notes that it can be difficult to transition to a low-FODMAP diet without assistance and recommends that you work with a registered dietitian if at all possible.

Bloating can also be caused by certain medical conditions. According to the American Academy of Family Physicians (AAFP), bloating can be a symptom of gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), pelvic inflammatory disease (PID), Crohn's disease, certain cancers, liver diseases and a bowel or bladder blockage. However, the academy notes that temporary bloating is typically not a sign of anything serious.

If possible, slowly tweaking your diet over time rather than overhauling your eating habits overnight can help you avoid unpleasant bloating. However, if that ship has sailed, there are certain things you can do to help address bloating symptoms.

"One way to prevent excess bloating is with hydration," says Megan Antoni Placa, CNS, LDN, a licensed and board-certified clinical nutritionist in New Jersey. "When increasing the fiber in the diet, it's important to increase water intake," she says. "I advise my clients to drink half their body weight in ounces [each day]. This means for a person that is 140 pounds, 70 ounces of water is ideal."

Read more: Does Drinking Water Reduce Bloating?

The AAFP recommends that you avoid chewing gum and try over-the-counter remedies to reduce gas. The academy also says that certain probiotics can mitigate bloating, as can certain herbal remedies, including peppermint and chamomile tea, anise, caraway, coriander, fennel and turmeric.

If you're experiencing gas and bloating after a diet change, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) suggests avoiding or limiting high-fat foods, carbonated drinks and foods that are high in sugar.

If symptoms of bloating, gas, constipation or diarrhea are persistent or interfering with your everyday life, NIDDK recommends speaking to your doctor to get checked out for a food allergy or intolerance like 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.