Belly bloat can be uncomfortable as well as unattractive. That sensation of fullness around the abdomen becomes more common as we age because our bodies produce less stomach acid, which is responsible for activating certain enzymes that help break down foods.

Therefore, food remains in the stomach longer, generating more gas in the digestive tract. Bloating can occur from several causes such as lack of fiber in your diet, food intolerance, irritable bowel syndrome, or a serious condition such as colon cancer.

According to AARP, if you’ve had a colonoscopy and ruled out colon cancer, chances are your discomfort comes from dietary sources. Nutritionists recommend charting the foods that seem to cause bloating. This can help track patterns and point out foods to eliminate. There are free apps like Symple Symptom Tracker that can facilitate identifying the foods that cause discomfort.

Here are six of the most common culprits that can trigger bloating:

• Milk, cheese, or other dairy products. It’s very common to develop lactose intolerance later in life, says Sandra J. Arevalo Valencia, director of community health & wellness at Montefiore Nyack Hospital in Nyack, New York. With age, we produce less of the enzyme (lactase) we need to digest lactose in milk. Dairy digestion can also cause gas, pain, and diarrhea. Using products like Lactaid or drinking lactose-free milk can help.

• Beans, lentils, almonds, and whole grains. The high fiber in legumes and other foods can cause bloating and pain. Soaking lentils and beans before you cook them may make them easier to digest, says Healthline.

• Artificial sweeteners. Products like sorbitol and mannitol may reduce calories in food, but because they aren’t fully digested in the small intestine they can cause gas and bloating, says AARP. If there is a warning on the package that excess consumption can cause laxative effects, it’s a good sign that the item is an artificially sweetened food that can cause gastrointestinal symptoms.

• Wheat. Wheat has been a controversial food over the past few years because it contains a protein called gluten which is hard to digest for individuals with celiac disease or gluten sensitivity. Wheat is also a source of FODMAPs, short-chain fatty acids that escape digestion and are then fermented by gut bacteria in the colon. Gas is a common byproduct of this process.

• Broccoli and other cruciferous vegetables. The cruciferous family includes broccoli, cauliflower, cabbage, Brussels sprouts, and others. While these vegetables are highly nutritious, they, too, contain FODMAPs and can cause bloating in certain people. Switch to other vegetables if that’s the case.

• Onions. Even though onions are often eaten in small quantities, they are one of the main sources of fructans. These are soluble fibers that can cause bloating. Additionally, some people are sensitive or intolerant to other compounds found in onions, especially raw onions. According to Healthline, cooking them helps improve digestibility.