In the past five years, several new drugs have been brought to market that could lead to a profound, if not revolutionary, change in how health care providers – and the public – view weight loss.
Three drugs in particular – sold under the brand names Wegovy, Ozempic and Mounjaro – have shown remarkable effects on weight loss in clinical trials.
While Wegovy is approved by the Food and Drug Administration for weight loss, the other two medications are only approved as treatment for Type 2 diabetes, though they do also contribute to significant weight loss. This has led to increased demand for these drugs, causing a shortage of Ozempic and Mounjaro in early 2023 that threatened the availability of these drugs for diabetes patients.
Globally, more than 650 million people are obese, and by 2030, an estimated 1 billion adults will be obese. This makes obesity the most prevalent chronic disease in the world.
As an exercise science scholar, I have spent more than 15 years studying the effects of diet and exercise on the human body, primarily focused on body composition changes such as gaining skeletal muscle or losing body fat, or both. In my lectures, I present data on the detrimental impacts on personal health of being overweight or obese. Then I show that, aside from surgical intervention, the best way to lower body fat is with starting an exercise program and improving dietary habits.
These new drugs have now altered what I teach in the classroom, and as a researcher I believe they raise many questions about the current approach to weight management and health. While these medications hold promise, they are not wonder drugs. In my view, they warrant much more research before they become the basis for a new weight management protocol.
How these drugs work
Ozempic and Mounjaro are FDA-approved for the treatment of Type 2 diabetes, which affects more than 37 million people in the U.S. On top of that, nearly 100 million people are considered prediabetic, meaning that together over 40% of the U.S. population suffers from an inability to properly manage blood sugar.
Obesity and Type 2 diabetes are closely related conditions, so much so that some experts are now calling the two conditions “diabesity.” These dire figures are what prompted pharmaceutical companies to search for new weight loss treatments.
Type 2 diabetes is a condition in which your body no longer responds to the hormone insulin, which in healthy people regulates glucose, or sugar, levels in the blood. Prolonged elevated blood sugar, if left untreated, can lead to heart disease, vision loss and even death.
Wegovy and Ozempic are a class of drug known as a semaglutide. Since people with Type 2 diabetes are unable to properly manage blood sugar, injections with this class of drug help the body release the proper amount of insulin after eating by mimicking a naturally occurring hormone called GLP-1.
At the same time, semaglutides also reduce the release of the hormone glucagon, which works opposite of insulin to increase blood sugar. In non-diabetics, these two hormones work together to maintain normal blood sugar levels. But since this mechanism is not functioning properly in diabetics, which leads to high blood sugar, semaglutides help to control blood sugar and also reduce appetite.
For this reason, Ozempic received approval from the FDA in 2017 as a treatment for Type 2 diabetes. But during the clinical trials for Type 2 diabetes, pharmaceutical companies quickly recognized Ozempic’s potential as a weight loss tool.
This led to the release of a new drug, Wegovy, which has a higher dose of semaglutide. A 2021 study showed that once-weekly injections of Wegovy over the course of 68 weeks resulted in about a 15% loss of body weight in adult participants with obesity.
The other novel medication in the news lately, Mounjaro, acts like a semaglutide, stimulating GLP-1, but it also mimics a second hormone called glucose-dependent insulinotropic polypeptide. This dual-hormone action works to not only lower blood sugar levels and increase insulin sensitivity, but also slows the digestive system and decreases appetite.
