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Weight-Loss Devices: How They Work | ASHARQ AL-AWSAT English Archive 2005 -2017
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A man crosses a main road as pedestrians carrying food walk along the footpath in central Sydney, Australia, August 12, 2015. REUTERS/David Gray

Stomach balloons and other devices may help people eat (or absorb) less food. But does the weight loss last?

For the millions of Americans who have obesity, the burden of excess weight is much more than meets the eye. This chronic, debilitating condition leaves people prone to many serious illnesses, including heart disease. But for many, diet and exercise often prove frustratingly futile (see “What’s a healthy weight?”)

What’s a healthy weight?

The body mass index (BMI) estimates whether a person has a healthy (normal) or unhealthy amount of body fat (overweight or obesity). Calculate yours at www.health.harvard.edu/bmi. Weight-loss devices are approved for people who fall into the obesity category.

Surgically removing a particular part of the stomach, known as sleeve gastrectomy, spurs substantial weight loss. It also leads to dramatic improvements in type 2 diabetes and other problems closely linked to heart disease, such as high cholesterol and high blood pressure. Yet only about 1% to 2% of people who qualify for this and other forms of weight-loss (bariatric) surgery undergo it. Although one big issue is the high cost (at least $20,000) and variable insurance coverage, other concerns may be just as pressing.

“People are not just worried about having major surgery. They’re also scared by the thought of making a permanent change to their gastrointestinal anatomy,” says Dr. Ali Tavakkoli, co-director of the Center for Weight Management and Metabolic Surgery at Harvard-affiliated Brigham and Women’s Hospital. That’s why a less risky, nonpermanent intervention to aid weight loss appeals to some people, he says.

FDA-approved devices

Research in this realm is not new: the first gastric balloon — an inflatable sphere placed in the stomach to fill space — was approved in 1985. (It didn’t last long; some people developed intestinal blockages and other serious complications.) Since then, design advances have led to several safer, more effective gastric balloon systems.

These and two other FDA-approved devices (see “Weight-loss devices”) are intended to be used in tandem with healthy eating and exercise habits. The problem is that these devices don’t come close to the effectiveness of bariatric surgery, which usually helps people lose about 25 to 40% of their total body weight, says Dr. Lee Kaplan, who directs the Obesity, Metabolism, and Nutrition Institute at Harvard-affiliated Massachusetts General Hospital.

In clinical studies testing these devices, people in the comparison groups (diet and exercise alone) typically lose about 3% to 4% of their total body weight. The vagus nerve block adds only about 1% to that total, which makes this high-cost procedure hard to justify. Gastric balloons are slightly better, helping people lose another 4% to 5% of their original weight. But the balloons must be removed after six months, after which weight regain is common.

The stomach drain, which can be left in the body as long as needed, has the best results: an additional loss of about 8% to 9% of original body weight. As a result, it’s potentially the most promising of these devices, says Dr. Kaplan. “The downside is what many people call the ‘yuck factor,’ since it involves draining partly digested food from the stomach into a toilet,” he says.

His advice to people considering a device is to first try anti-obesity medications in consultation with a physician familiar with all the different drug options. On average, these drugs are as effective as gastric balloons, and doctors know much more about their safety and long-term effectiveness.

Weight-loss devices

These devices are FDA-approved.

Gastric balloons ( ReShape , Orbera , Obalon )

These balloons are placed through a flexible tube (endoscope) passed through the mouth into the stomach (Reshape and Obera) or by swallowing a capsule attached to a tiny catheter (Obalon). Once inflated with gas or fluid, the balloons leave less room in the stomach, so the person often feels full sooner and eats less.

Vagus nerve block (Maestro)

This device, which is surgically placed in the abdomen, periodically blocks nerve signals between the brain and the stomach. This apparently helps regulate hunger and fullness, although the exact mechanism isn’t clear.

External stomach drain device (Aspire Assist)

A surgically placed tube can drain part of the stomach contents outside of the abdomen, usually into a toilet. Doing so about 20 minutes after each meal allows people to eliminate up to 30% of the calories they consume.

(Harvard Heart Letter)