Metamucil is a safe alternative for diabetics to gain a decent amount of fiber, as discussed by Diabetes Self-Management. An individual needs to check the ingredient list and consult his doctor before taking any supplement.
Fiber has an abundance of nutrition benefits, and dietitians recommend that patients receive fiber from food sources. Metamucil contains psyllium, and it's a good way to add to a diet that is lacking in fiber, according to Diabetes Self-Management, as very few people get the recommended amount of fiber in their daily diet. Metamucil is generally well tolerated, but potential side effects include bloating and a feeling of fullness.