The future of weight loss could look like this. Inject your muscles with a compound that helps them burn more calories than usual and then do your daily chores to shed those extra pounds. That's the vision of a team of scientists who are working on a muscle-targeted injection therapy to help overweight people lose weight easily, even with low to moderate exercise.

Biologically, it's tough to lose weight because our bodies are designed to be energy efficient. Any time there's a decrease in calorie intake, the body boosts its energy efficiency to counter weight loss. However if you could make muscles less energy efficient, they would burn more calories, even with mild levels of exercise. In a recent study, researchers from the University of Iowa and the Iowa City VA Medical Center demonstrated how they've been able to achieve this result in mice, overriding the muscles' tendency to conserve energy.

"This study shows for the first time that this energy efficiency can be manipulated in a clinically translatable way," says study co-author Denice Hodgson-Zingman, MD, UI associate professor of internal medicine.

The team injected a compound called a vivo-morpholino into the thigh muscles of a mouse. The compound suppresses the production of a protein called ATP-sensitive potassium (KATP) channel that's responsible for regulating the energy efficiency of skeletal muscles; it determines the amount of energy used. The injected muscles experienced protein loss and burned more calories than those that weren't injected as the mouse moved on the treadmill.

"The disruption of the KATP channels results in changes of the muscles' electric properties, which in turn increase calcium turnover," Sivaramakrishna Koganti, a postdoctoral research scientist in Dr. Zingman's lab tells Gizmag. "This change in the calcium handling requires more energy, and thus every time the muscle contracts, it consumes more energy compared to the muscle with the intact KATP channel function."

Additionally, the injection affected only the muscles in the thigh without impacting neighboring muscles or other organs. That's important, the team states, as its approach makes it possible to affect only the desired muscles locally, without disrupting others throughout the body which may result in undesirable side effects.

Their work could lead to a therapy that makes it easier to lose weight by taking a shot in the leg or arm, just before undertaking everyday tasks or light exercise. This approach, however, doesn't mean forgoing a healthy diet or exercise. The idea here is to jump start the weight loss process by overriding the body's natural tendency to save energy.

While more work is needed to develop the compound for human use, the team hopes that its work will lead to an injection therapy suitable for people struggling with obesity, who might not be able to engage in exercise due to health complications like heart disease, arthritis and more. Combined with a better diet and activities they can manage, the injections could help overweight people achieve their weight loss goals more easily.

"With this intervention, the benefits of exercise in burning calories could be accessible to a broader range of people by making the calorie burning effects of skeletal muscle greater even at low levels of activity that most people would be able to undertake,"says study co-author Leonid Zingman, MD, UI associate professor of internal medicine and a staff physician at the Iowa City VA Medical Center.

The study has been published in the journal Molecular Therapy.