Understanding How Weight-Loss Medications Treat Obesity

Obesity is defined as excess body fat that poses a health risk. It is a chronic disease that can be caused by genetic or developmental factors, or other issues.

Doctors can use a few different measures to help determine whether you are affected by obesity. The first is using your weight and height to calculate BMI (body mass index).

Although BMI is not a perfect measure, as it doesn’t distinguish between muscle and fat tissue, it is an important clinical marker.

• Normal weight: 18.5-24.9
• Pre-obesity/overweight: 25-29.9
• Class 1 obesity: 30-34.9
• Class 2 obesity: 35-39.9
• Class 3 obesity: 40 and up

To help determine abdominal obesity, doctors can use waist circumference. Generally, obesity in men is seen with a waist circumference greater than 40 inches. For women it is greater than 35 inches. However, that number can vary based on ethnicity.

Finally, you could use DXA or displacement scans to determine the percentage of body fat, but these tend to be expensive.

The greatest benefit is reducing your chance of an early death. Treating obesity may also help reduce your risk of certain cancers.

Obesity can contribute to elevated blood pressure and elevated blood glucose, so reducing your weight may help lower that blood pressure and treat prediabetes.

Additionally, women with polycystic ovary syndrome (PCOS) are more likely to have pre-obesity and obesity. Losing weight is an effective treatment to improve PCOS symptoms and even restore ovulation. It can also help treat heavy periods or lessen the effects of menopause.

Carrying extra weight can put stress on your joints and lead to immobility. When you treat obesity, it improves joint pain and inflammation and may resolve GERD or acid reflux symptoms. Treatment can also improve obstructive sleep apnea.

Dr. Finkle said the pillars of treatment are nutrition, physical activity and behavioral or lifestyle changes. Often those recommendations include eating fewer carbs, increasing protein intake, doing strength or resistance training and moving more. However, any changes should be sustainable. The goal is to make a lifelong change.

When obesity is a chronic medical condition, it may be time to consider adding in medications or having bariatric surgery.

Medications to treat obesity have been around for decades. Some commonly used ones are:

• Orlistat (over the counter)
• Liraglutide (Saxenda)
• Naltrexone/Bupropion (Contrave)
• Phentermine/Topiramate (Qysmia)
• Semaglutide (Wegovy)
• Tirzepatide (Zepbound)

Anti-obesity medications take effect in the brain and gut to help change your biology. They reduce hunger and food cravings, reduce the amount you eat and increase the satisfied feeling of being full.

Some medications are taken orally while others are injected.

Generally, patients see a 5-10% reduction in their weight when taking anti-obesity medications. Some medications may produce 15-20% weight loss in one year.

A BMI over 30 generally qualifies you for anti-obesity medications. If you have a BMI over 27 and an additional condition related to obesity – such as high cholesterol, diabetes, sleep apnea or others – you may also qualify for treatment.

However, one common challenge is getting insurance coverage for these medications. Certain insurances do not have any weight-loss benefits. Some will cover treatment for metabolic syndrome, diabetes or prediabetes. It’s essential to work with your doctor, nurse and pharmacist to get prior authorizations for this treatment.

The most common side effect of these medications is nausea and vomiting. Other side effects may include irregular heart rate, insomnia, dry mouth, constipation, diarrhea and elevated blood pressure. Some medications may increase the risk of pancreatitis and stomach pain.

“The medications are so good, and patients are losing weight so fast, I do a lot of counseling because you do lose a lot of lean muscle mass,” said Dr. Finkle. “Patients have to eat a lot of protein (80 grams) and drink a lot of water (60 ounces). Also focus on strength training to counteract lean muscle loss.”

Some patients will need to take this medication for the rest of their lives. In other cases, you may be able to transfer to an alternative treatment. Finally, some may be able to go off medications but continue to monitor their weight for changes. There isn’t a hard and fast rule.

Most of these medications are approved for long-term use.

The first step is to make sure you and your doctor have addressed any underlying factors that could contribute to weight gain. Some medications are known to contribute to weight gain, such as certain birth control, anti-hypertensives, antidepressants and more. You may need to search for an alternative.

Bariatric surgery may also be an option. The requirements for bariatric surgery are a bit different, so learn more and talk with your doctor.