Obesity is a modern epidemic. In a 2011 to 2012 assessment of body mass index (BMI), statistics showed over two thirds of American adults were overweight or obese and over one third were obese. Experts consider 18.5-24.9 to be a healthy BMI, BMI over 27 “overweight”, and BMI over 30 “obese”. There are currently 1.9 billion overweight adults and 600 million obese adults worldwide, and these numbers soar even higher when including children. Obesity is linked to multiple chronic health problems, including back pain, high blood pressure, high cholesterol, diabetes, and plaque build-up in the arteries that may cause heart disease and stroke.
Given the severity of the obesity epidemic, it is no wonder there is such a focus on weight loss medications. There are currently five weight loss drugs approved by the Food and Drug Administration (FDA) for adults who are obese and have at least one related health condition, such as type 2 diabetes: orlistat (brand name Alli), lorcaserin (Belviq), naltrexone-bupropion (Contrave), phentermine-topiramate (Qsymia), and liraglutide (Saxenda).
For a recent study published in the Journal of the American Medical Association (JAMA), researchers collected data from 28 weight loss trials to compare the effectiveness of these five medications. All trials included use of at least one of the pills for a minimum of one year and compared results to either placebo or another weight-loss pill. Participants had a median average weight of 100.5 kg and BMI of 36.
The studies showed the five drugs were more effective than placebo at helping adults lose weight. On average, study participants achieved at least a five percent weight loss, the minimum required in weight-loss drug trials for marketing approval.
Of the five pills, Qsymia achieved the most weight loss, with people who took Qsymia losing an extra 8.8 kg compared to placebo. Study participants taking Qsymia also had the highest chance of losing 10% of their baseline weight. Saxenda came in second place after Qsymia, but more study participants stopped taking the pill because of side effects. Contrave, Belviq, and Alli came in third, fourth, and fifth place, respectively.
In general, side effects vary from one weight loss pill to another and can include upset stomach, diarrhea or constipation, headache, dry mouth, dizziness, and nausea. The study found that Qsymia, Saxenda, and Contrave had the highest rates of side effects, with 10 to 25% percent of adults discontinuing the pills before the end of the year due to adverse effects. Belviq and Alli had the lowest rates of side effects, and only 7 to 8% of adults stopped taking them early on in the study. However, Alli also resulted in the least weight loss, only an average of 2.6 kg more than placebo.
Where does this leave adults who are trying to lose weight? There is no easy answer. Although it is tempting to choose the medication that will take off the most weight, choosing the right drug is a personal decision that someone should discuss with a doctor. Some people can be more sensitive to medications than others and may want a pill that has a lower rate of side effects, even if it does not help them shed as many pounds. Also, because some of the drugs already treat other conditions, they may be more appropriate for adults who have these health problems. For example, Saxenda exists under another brand name as a diabetes medication.
One of the most important points to remember about weight loss is that lifestyle changes play a huge role in shedding those initial pounds and keeping the weight off. All of the studies the authors examined included exercise counseling in their strategies for weight reduction, so the outcomes might have been better because people started exercising more while taking weight loss drugs. The American Heart Association recommends 150 minutes per week of moderate exercise, such as brisk walking, and a balanced diet that emphasizes fruits and vegetables, whole grains, low-fat dairy products, lean meat and fish, nuts and legumes, rather than red meat and processed foods high in saturated and trans fats and salt. Overall, it is important to remember that while weight loss medications can go a long way in helping someone lose weight, they have side effects. Always use weight-loss drugs with caution and in conjunction with a healthy diet and regular exercise.
Guest article edited by Ross Cummings.