If you’ve ever announced to the world — maybe on social media — that you wanted to shed a few pounds, you may have heard this advice from your friends: eat healthier and exercise more.

It seems like a simple way to lose weight.

The same way tackling Mount Everest is just a matter of hiking farther and climbing higher.

For many people who are obese or overweight, though, getting that first toehold toward a healthier weight — as well as a lower risk of heart disease, type 2 diabetes, stroke, and some types of cancer — seems like an insurmountable task.

But there are tools other than sheer willpower to help people get started.

A new study shows that, for some people, one of these may be a prescription weight loss drug.

“I view these medications as potentially being used to 'kick start' weight loss,” study author Dr. Siddharth Singh, a gastroenterologist at the University of California, San Diego, told Healthline in an email, “but a comprehensive lifestyle change with a healthy well-portioned diet and exercise is needed to make a lasting change.”

Read More: Obesity Rates Up for Women, Teens … Same for Men »

Anti-Obesity Drugs

In the study, published online today in the Journal of the American Medical Association (JAMA), researchers combined the results of 28 previous randomized clinical trials — what’s known as a meta-analysis.

This allowed the researchers to compare the safety and effectiveness of weight loss drugs that may not have been tested alongside each other in the original studies.

Combined, the studies included 29,018 people who were overweight and obese and taking an FDA-approved weight loss drug or a nonactive placebo.

Researchers compared the following weight loss drugs — orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, and liraglutide.

On average, between 44 and 75 percent of the people taking one of the weight loss drugs lost at least 5 percent of their body weight after one year.

That compares to 23 percent of the people in the placebo group who lost that much weight.

In addition, during that year people who took a weight loss drug lost on average between 5 and 19 pounds more than people in the placebo group.

The results did include all people who started the study and had at least one weight measurement after the start — even if they dropped out early.

“While this type of data is certainly important for regulatory reasons, it largely underestimates what patients can expect to lose with use of these medications,” Dr. Scott Kahan, M.P.H., director of the National Center for Weight and Wellness, told Healthline in an email.

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Concerns About Safety

Although all of the drugs were used to promote weight loss, each works in different ways.

Some of the drugs decrease appetite or increase feelings of fullness. Liraglutide also slows the emptying of the stomach. And orlistat acts by keeping the intestines from absorbing some fat from food.

In spite of their effectiveness, weight loss medications may still be underutilized.

A 2007 to 2008 survey published in the Annals of Epidemiology found that less than 3 percent of people used prescription drugs to lose weight during the previous year.

“One [reason] is that medications are currently not well-covered by insurance companies,” said Kahan, “thus they are not accessible to many people who could benefit from them.”

Weight loss drugs also have a bad reputation due to several being pulled from the market in the past due to safety concerns — dexfenfluramine and fenfluramine in 1997, and sibutramine in 2010.

“There is also a perception that they are not safe, which is in some ways amusing,” said Kahan, “as many of these medications are already approved and used for other purposes, and their safety isn't generally questioned in those cases.”

To address potential concerns, the Endocrine Society recommends that patients taking an approved weight loss drug have regular check-ins with their doctor to look for safety problems and to make sure the drug is a good fit.

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Side Effects Limit Use

But even if the drugs are safe, they all carry side effects.

In the new study, the researchers found that people taking one of the three best performing drugs were also more likely to stop treatment because of bad side effects.

Side effects vary among the drugs, ranging from headaches and dizziness to changes in bowel movements. Liraglutide may also increase the risk of thyroid tumors.

When deciding on whether to take a weight loss drug, patients can balance its benefits with the side effects.

For best weight loss results, though, they should incorporate healthier eating, diet, and behavioral changes in their life.

“Treatments such as medications and surgery should be used alongside behavioral changes,” said Kahan. “Of course, every patient is different and treatment should be customized.”

To help doctors and patients make decisions about what approach to losing weight is best, the authors of the new study call for more research. This might include directly comparing the benefits of weight loss drugs, surgery, and behavioral interventions.

“It is important to study the comparative effectiveness of these interventions as well as weight loss strategies — combining several interventions simultaneously or sequentially — to find the right approach for each patient,” said Singh.

The new study only looked at weight loss over one year. More research is also needed on the long-term effectiveness and safety of the drugs.

For some people, weight loss drugs may be the help they need to break the cycle of weight loss and regain.

“Medications can be used in many ways, and one of those ways is to improve long-term weight loss and help prevent regain,” said Kahan. “To some degree they may be more helpful in this capacity, as this is for many people the most difficult part of their journey.”