Metformin is undoubtedly the most prescribed oral medication for type 2 diabetes in the United States. Its widespread use is attributed to many reasons that include demonstrated effectiveness in controlling high blood sugar, a proven mortality benefit, little to no risk of causing hypoglycemia (low blood sugar), and a comparatively inexpensive price. It does not have an indication for weight loss; however, some data suggests it may produce weight loss in some individuals or limit the weight gain caused by other medications such antipsychotics, HIV medications, insulin, sulfonylureas, and thiazolidinediones.
How metformin may cause weight loss
Unlike insulin, sulfonylureas (glimepiride, glyburide, glipizide) and thiazolidinediones (Avandia, Actos) metformin is considered a weight “neutral” diabetic medication. Insulin causes weight gain because excess sugar stored in cells is converted to fat. Sulfonylureas increase insulin levels in the blood and thiazolidinediones help improve the uptake of insulin into cells, making weight gain a common side effect of these medications. Metformin slows absorption of sugars in the small intestine and reduces levels of hormones associated with hunger. By slowing the absorption of sugar, metformin helps control blood sugar and provides a feeling of satiety when eating. Reducing the level of hormones associated with hunger after eating carbohydrates will also contribute to satiety. Satiety results in a decrease in food consumption, which could lead to weight loss.
Next: Weight Loss In Patients With Diabetes