In the United States, 40% of adults are obese. Being overweight or obese increases your risk of type 2 diabetes and cardiovascular disease. We know that losing weight and exercising are very healthy. However, it is not easy to lose weight, and being overweight can make it hard to exercise. Researchers are now showing that some medications can make weight loss hard for people who are obese. These medications include insulin, oral glucose lowering drugs called sulphonylureas (such as Gliclazide), and medications for depression (such as Amitriptyline). This study also showed that these medications make surgery for obesity (such as stomach reduction surgery) less effective. Other studies have shown that drugs used to treat serious mental illness and seizures can contribute to obesity. The number of overweight people in America will likely increase, so doctors should pay close attention to the medications that patients take. If a patient gains excess weight, doctors can ask if the drug did it.