Lentils

Lentils offer the best two-for-one value on this list, tackling both protein needs and the constipation affecting roughly 1 in 7 GLP-1 users. A 100-gram serving provides 9 grams of plant protein and 8 grams of fiber—primarily soluble fiber that softens stool and supports gut health without the harshness of pure bran. They also deliver 45% of the daily value for folate and 18% for iron, addressing deficiencies flagged by Harvard in a notable subset of GLP-1 users. UC Health and Cleveland Clinic specifically recommend legumes for their simultaneous protein, fiber, and blood-sugar benefits. Cooked soft or puréed into dal or soup, lentils are easy on a slow stomach. However, their high fiber can cause gas if introduced too quickly, so dietitians recommend adding just 5 grams of fiber per week.