Metamucil is used to complement loss of weight but does not directly cause weight loss. Metamucil contains a high amount of psyllium, a soluble fiber that turns into a gel when combined with liquid. The body feels full, thus reducing signs of hunger, causing one to eat less.
One weight loss benefit that comes from consuming Metamucil is its ability to aid in controlling and stabilizing blood sugar levels. Fluctuations in blood sugar levels cause an increase in appetite. In addition, the high amount of psyllium husk in Metamucil helps prevent the onset of high cholesterol, heart disease and diabetes.