A weight loss device helped rats lose 40 percent of their body fat. Could it work in humans?

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Study Identifies Weight Loss Drug That Works Without Heart Risks

Researchers from the University of Wisconsin-Madison may have discovered a new way to tackle worldwide obesity, a major risk factor for a plethora of chronic diseases, including diabetes, cancer and heart disease.

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"In vivo vagus nerve stimulation holds great promise in regulating food intake for obesity treatment," graduate student Guang Yao and principal investigator Xudong Wang wrote in their study recently published in the journal Nature Communications.

This process involves tiny battery-free, implantable devices that aid weight loss. In fact, when researchers tested the devices on rats in a laboratory setting, the rats shed 38 percent of their body weight within 100 days.

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"Measuring less than 1 centimeter across, or about a third of the area of a U.S. penny, the tiny devices — which are safe for use in the body and implantable via a minimally invasive procedure — generate gentle electric pulses from the stomach's natural churning motions and deliver them to the vagus nerve, which links the brain and the stomach," scientists wrote in a university article.

The “gentle electric pulses” help control food intake by tricking the brain “into thinking the stomach is full after only a few nibbles of food.”

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When Yao and Wang removed the devices from the rats after 12 weeks, the rats resumed normal eating patterns and regained the weight, meaning the effects are reversible.

In 2015, another unit that works by stimulating the vagus nerve for weight loss, was approved by the Food and Drug Administration. But the device, called "Maestro," involves "high-frequency zaps" and requires bulky batteries that must be frequently recharged.

Unlike “Maestro,” Yao and Wang’s new device doesn’t require external battery charging, “a significant advantage when you consider the inconvenience that patients experience when having to charge a battery multiple times a week for an hour or so,” surgery professor Luke Funk said in a university article.

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The new device instead relies solely “on the undulations of the stomach walls to power its internal generators,” making it automatically responsible to body function.

The weight loss tool has been patented through the Wisconsin Alumni Research Foundation and will be tested in larger animal models, and if successful, in human trials.

Future clinical trials may also include a switch to control treatment. Integrating such a shutter switch to the electrical wires from the VNS device has proven “a disconnected device has no impact to food intake and weight change,” researchers concluded.

“Our expectation is that the device will be more effective and convenient to use than other technologies,” Wang said.

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Until now, the most common non-surgical and surgical treatments to tackle obesity have included invasive gastric bypass surgery or weight loss drugs with problematic side effects and possibility of weight rebound.

“Recent breakthroughs in neuromodulation for body weight control” including the aforementioned technique involving the vagus nerve “have provided potential opportunities for therapeutic interventions and brought renewed promises and vitality to the development of new anti-obesity strategies,” scientists wrote in the study.

According to the World Health Organization, global obesity has nearly tripled since 1975. In the United States, obesity affects about 13.7 million children and adolescents and 93.3 million adults.

Read the full study at nature.com.