
Legumes are notorious for causing stomach trouble. “Some people who have digestive issues may not tolerate legumes well, as they may cause gas, bloating, or other symptoms of indigestion,” Poe says.
Legumes’ effect on your stomach may be due to their fiber content. If your diet is lacking in fiber and you suddenly start eating high amounts, you may well feel gassier than usual. But everything should go back to normal once your body adjusts to the increased fiber intake, according to the Cleveland Clinic.
You can also add legumes to your diet gradually — start with 2 to 4 tablespoons (tbsp) of beans or lentils at a time, then increase your intake as your body adjusts. Drink plenty of water to offset legumes’ effects on your stomach, too.
Legumes also contain lectins, which when eaten raw can lead to symptoms including nausea, vomiting, diarrhea, bloating, and gas, according to the Harvard T.H. Chan School of Public Health.
Lectins are an “antinutrient,” and some say they cause obesity, chronic inflammation, and autoimmune diseases, but these potential negative effects are canceled after cooking.
Poe suggests starting your legume journey with lentils. “Some people find lentils easier to digest than other starchier legumes like black beans or chickpeas, so start with lentils if other legumes cause too much digestive distress,” she says.