Metformin is a medication that is commonly used to treat type 2 diabetes, and it has been found to have the side effect of weight loss, making it a popular choice for people with type 2 diabetes who are struggling with obesity. While the exact mechanisms through which metformin causes weight loss are not fully understood, several possible explanations have been suggested through research. Despite the known glucose-lowering effects of metformin, there has been clinical interest in its potential as a weight loss drug. In this article, we discuss the potential mechanisms by which metformin can decrease appetite and oppose unfavorable fat storage in peripheral tissues.
Firstly, metformin improves insulin sensitivity, which can lead to weight loss. Insulin is a hormone that regulates glucose (sugar) in the body. In people with type 2 diabetes, insulin resistance can occur, meaning that the body becomes less responsive to insulin. This can lead to high blood glucose levels, contributing to weight gain. By improving insulin sensitivity, metformin can help the body use glucose more effectively and reduce blood glucose levels. This, in turn, can lead to weight loss.
Secondly, metformin reduces glucose production in the liver. The liver plays a crucial role in regulating glucose levels in the body. In people with type 2 diabetes, the liver can produce too much glucose, which can lead to high blood glucose levels and weight gain. Metformin can reduce the amount of glucose produced by the liver, which can help lower blood glucose levels and contribute to weight loss.
Thirdly, metformin decreases glucose absorption in the intestines. After we eat, glucose from our food is absorbed into the bloodstream through the intestines. In people with type 2 diabetes, this process can be inefficient, leading to high blood glucose levels and weight gain. Metformin can reduce the absorption of glucose in the intestines, which can help to lower blood glucose levels and contribute to weight loss.
Many individuals struggle to maintain clinically relevant weight loss from lifestyle and bariatric surgery interventions. Long-term follow-up from the Diabetes Prevention Program demonstrates that metformin produces durable weight loss and that decreased food intake is the primary weight loss mechanism. Although the effect of metformin on appetite is likely to be multifactorial, changes in hypothalamic physiology, including leptin and insulin sensitivity, have been documented.
In addition, novel work in obesity highlights the gastrointestinal physiology and circadian rhythm changes by metformin as not only affecting food intake, but also the regulation of fat oxidation and storage in the liver, skeletal muscle, and adipose tissue. In addition to these mechanisms, metformin can also lead to decreased appetite and a feeling of fullness. Some studies have suggested that metformin can reduce cravings for high-calorie foods and increase feelings of satiety (fullness). This can lead to a decrease in calorie intake and ultimately contribute to weight loss.
It is important to note that while metformin can lead to weight loss, it is not a magic pill for weight loss. To achieve significant weight loss with metformin, it must be combined with a healthy diet and regular exercise. Metformin is not a substitute for a healthy lifestyle, but it can be a helpful tool for people with type 2 diabetes who are struggling to lose weight.
Furthermore, metformin may not be suitable for everyone. People with certain medical conditions, such as liver or kidney disease, may not be able to take metformin. It is important to discuss any concerns or questions with a healthcare provider before starting metformin.
In conclusion, metformin can cause weight loss through several mechanisms, including improving insulin sensitivity, reducing glucose production in the liver, decreasing glucose absorption in the intestines, and reducing appetite and increasing feelings of fullness. While metformin can be a helpful tool for weight loss in people with type 2 diabetes, it should always be used in combination with a healthy diet and regular exercise. People with certain medical conditions should speak with their healthcare provider before starting metformin.
Metformin induces modest weight loss in overweight and obese individuals at risk for diabetes. A more detailed understanding of how metformin induces weight loss will likely lead to optimal co-prescription of lifestyle modification with pharmacology for the treatment of obesity independent of diabetes.