Current clinical evidence suggests that psyllium taken just before meals (7–15 grams per day over periods ranging from 2–12 months) may lead to small reductions in body weight, BMI, and waist circumference in people with a BMI over 30.[1][2][3]
Psyllium’s potential weight loss benefits are often attributed to its purported ability to suppress appetite through increased intestinal water absorption or the reduction of ghrelin.[4][5][6][7][8][9] However, it should be noted that appetite suppression has only been observed in the participants who took 7.4–23 grams of psyllium immediately before a meal.[6][7][8]
Preclinical studies (animal models) suggest that psyllium may also prevent lipid (fat) absorption, but this has not been supported by human-based clinical evidence.[10][11]