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. Compared to #5 Cottage Cheese (Low-Fat), lentils provide fiber and folate that dairy entirely lacks; versus other legumes, red lentils cook faster and yield the gentlest texture, making them indispensable for vegetarians. However, their high fiber can cause gas if introduced too quickly, so dietitians recommend adding just 5 grams of fiber per week.