Maybe you resolved to lose weight this year. Or maybe you’ve given up after years of yo-yo dieting. Or maybe your doctor has suggested you could reduce your risk of everything from heart attacks to knee arthritis if you trim your weight. 

Or maybe you just can’t escape the catchy television ads, celebrity gossip and tantalizing news headlines about medications for weight loss.  

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Whatever your reason, a pair of Michigan Medicine obesity experts has teamed up to answer common questions about the roots of weight gain and the new options for treating a chronic condition that affects tens of millions of American adults. 

Keep reading to find answers from Lauren Oshman, M.D., a family medicine physician and board-certified obesity specialist, and Andrew Kraftson, M.D., an endocrinologist who directs Michigan Medicine’s Weight Navigation Program. 

They and their colleagues help University of Michigan Health patients pursue healthy and evidence-based weight control using multiple strategies. 

What factors affect someone’s ability to gain or lose weight?

Oshman: Obesity is an incredibly complex chronic disease. Gaining or losing weight is determined by our genetics, our hormones and other medical conditions, and even the medications that we are prescribed. Obesity is also driven by diets that are high in processed high-calorie foods and lifestyles that are sedentary and low in activity. Even the amount we sleep and stress in our lives can affect our body’s control of our body weight set point.

Is gaining and losing weight just a matter of how many calories you take in and how many you burn?

Oshman: Most people are taught that weight is a simple equation – eating less food than the energy you expend. It turns out that this equation is wrong! Weight is determined by a command center in the brain that is affected by hormones produced in the gut, fat cells, and glands. Even when people reduce their calories, the brain responds by slowing down the metabolism and other controls to keep your weight stable.

Why do some people find it so hard to lose weight even if they reduce calories and exercise?

Oshman: I explain to patients that the brain has a ‘hunger control center’ that drives our body weight to stay at a certain point. For most people with obesity, when they reduce calories and exercise, their body responds by a process called metabolic adaptation, in which our body releases hormones that activate the ‘hunger control center’ to drive us to eat more and be less active. It’s important for people to understand that our biology drives hunger, not that hunger drives our biology. 

What are the top reasons someone who is overweight or obese should want to lose weight?

Oshman: I treat obesity focused on complications. I don’t make specific weight-based goals for patients like being under 200 or 300 pounds! 

Obesity, especially severe obesity, is a risk factor for many other chronic diseases like diabetes and fatty liver disease. In addition, many people with severe obesity have chronic joint pain, sleep apnea and other conditions related to obesity.

My primary goal with every adult and pediatric patient, regardless of weight, is to have a healthy relationship with food and to eat in a nourishing way, and to have a life with fun movement and activity! Many of the people who come to me for care with obesity also have an eating disorder like binge eating disorder so I focus most on understanding how to help them develop the healthy habits they want.

We know from clinical studies that even 5% weight loss can help prevent and treat chronic conditions. For some conditions, like fatty liver disease, we aim for closer to 10-15% weight loss. I develop individualized plans focused on each patient’s personal goals, risk factors and medical problems. 

How long should someone try diet and exercise as a weight loss regimen before asking a doctor about medications or surgery? 

Oshman: I think it is great for people to take their habits into their own hands and work on a healthier lifestyle. This is foundational – we build medical recommendations on a strong base of healthy eating behaviors and activity. 

I hate the word diet, because I think of a diet as something that is not sustainable. I’d love for patients to start the new year with making small changes they want to keep for life. That being said, most people in clinical studies lose about 2% to 5% of their body weight with healthy habits. 

Personally I think that is great – getting to a stable and ‘happy’ weight that doesn’t fluctuate or yo-yo is a great goal. 

However, studies suggest that to achieve a weight loss of 10-15% most people would benefit from an anti-obesity medication, and to achieve more than 20% weight loss most people could benefit from surgery. With newer medications that will be approved by the FDA soon, this is changing and we are starting to be able to achieve 20-25% weight loss with medications.

Is body mass index an accurate measure of weight issues? What other ways to judge whether someone’s weight is a problem?

Oshman: I hate body mass index. It fundamentally disrespects the fact that all body shapes can be beautiful, functional, successful and happy. 

We call this metabolically healthy obesity, and I focus on healthy lifestyle just like I do for patients of every size in my practice. I use waist circumference and waist-to-height ratio to identify people who have higher ratios of visceral fat. This is fat that is stored right next to the vital organs like the heart and the liver and produces inflammation and hormones that drives obesity.

I also identify obesity-related conditions like fatty liver disease, type 2 diabetes, and sleep apnea as markers as someone who has metabolically unhealthy obesity and we focus on individualized treatment plans. 

What are the new/recently introduced medications that can accelerate weight loss, and are they FDA-approved for this purpose or for something else? 

Kraftson: As Dr. Oshman mentioned, our biology can make reasonable control of hunger and/or cravings challenging. Consequently, it may be helpful to use medications that help make hunger and cravings more manageable. When used long-term, these tools help with both weight loss and maintaining a healthier weight.

The “new” medications that have been gaining a lot of attention are actually not so new.

Back in 2005, we started using a type of medicine (called GLP-1 receptor agonists) to treat individuals with diabetes. Afterwards, it was recognized that these types of medicine also help decrease hunger, improve fullness, and help with healthier control of weight. 

“We want there to be recognition of obesity as a complex, multifaceted, chronic condition that may require specialized treatment tools - including medications - in addition to lifestyle efforts.”

Dr. Andrew Kraftson

In 2015, the FDA approved one of these medicines (Saxenda) for treatment of excess weight. In 2017, Ozempic was approved to treat individuals with diabetes and, in 2021, the same medicine was approved for treatment of weight - but under a different name (Wegovy). 

Some insurers also approve use of Ozempic even if the individual does not have diabetes - but this is called a non-FDA approved use of the medication. Many medical providers feel comfortable using the interchangeably since they are the same medication, whose scientific name is semaglutide.

Who’s the best candidate for weight-loss via medications? If someone has diabetes or prediabetes, and is overweight or obese, should they consider medications or surgery sooner than someone who doesn’t have these conditions?

Kraftson: If an individual would like medication treatment to be considered, it is important to ask a few questions:

• Have I been unable to achieve my health and weight goals despite six months of focused lifestyle efforts? 
• Am I particularly hampered by hunger and/or cravings? Does my body mass index (a measure that accounts for height and weight) fall into the clinically obese category (i.e., BMI 30 or higher)? 
• If not, does the BMI fall into the overweight category (BMI of 25-29.9) and do I have a weight-related health condition (such as prediabetes, high blood pressure, high cholesterol, etc)? 
• If applicable, has my mental health care team agreed that it is appropriate to consider additional steps for healthy weight control?

If “yes”, then it may be helpful to have a conversation with a physician to discuss whether it would be useful to use medication. There are some situations where the physician and individual may decide that it is best to start both focused lifestyle efforts and medication - rather than waiting six months. 

What percentage of body weight can someone lose with these medications? 

Oshman: I tell my patients that everyone is different! In one clinical study, some patients with obesity gained weight on an anti-obesity medication, while some lost more than 20% of their body weight.

While on average, patients lose anywhere from 5-15% of their body weight in clinical studies of these medications, I tell my patients that the real goal is not a specific number on their scale. Even 5% weight loss (and avoiding additional weight gain) can improve our overall health. 

Are patients having trouble getting access to these medications because so many people are being prescribed them? Are you concerned that people who are not good candidates are getting these medications anyway, and reducing the supply for others?

Oshman: The manufacturers of some newer anti-obesity medications have had a difficult time keeping their drugs in stock. Part of this is due to demand and part of this is due to supply chain issues and their manufacturing plants. 

Other anti-obesity medications, like brand name Contrave and Qsymia, have been widely available. It is important for doctors to talk to patients about their specific health conditions and eating behaviors to individualize the right medication choice for them. 

Does insurance cover weight-loss medications? If a person’s insurance won’t cover it, how much does it cost per month?

Oshman: Many health insurance companies cover anti-obesity medications. In the state of Michigan, Medicaid also covers anti-obesity medications. 

Medicare does not cover anti-obesity medications. I work with the Obesity Action Coalition, an advocacy group that is advocating for Medicare to treat obesity equal to other chronic diseases and cover medications for obesity treatment. 

If your health insurance does not cover brand-name medications to treat obesity, they can be unaffordable – costing from $100 to over $1000 per month! Your doctor may recommend one or more inexpensive generic medications that have similar effectiveness and safety for treating obesity. 

Do people who start on weight-loss medications need to take them for the rest of their life?

Oshman: Obesity is a chronic metabolic disease, much like hypothyroidism. I prescribe thyroid hormone for patients with hypothyroidism to keep their thyroid levels in normal range. When they stop the medication, their thyroid levels drop again. 

Obesity treatment works in the same way. Because obesity is a chronic condition, the treatments, whether they be lifestyle changes, surgery, or medication, are prescribed long-term.  

Do we know much about the short- and long-term effects and risks of the newer medications? 

Kraftson: The injectable weight control medications affect the gastrointestinal tract and the body needs time to adjust. 

Approximately one-third of individuals will experience nausea in the first week of therapy. If certain precautions are not taken, vomiting may occur. For the majority of affected individuals, the symptoms are temporary and will resolve. However, some individuals will need to stop the medicine.

Bowel function is also affected in 20% of individuals. This could mean either diarrhea or constipation and we cannot predict which of these effects may occur. Some individuals can also become dehydrated - especially those experiencing gastrointestinal side effects. However, some individuals simply forget to drink water and become dehydrated. Therefore, individuals need to strive for adequate hydration. 

There has also been concern that these medications can increase the risk of pancreas inflammation (called pancreatitis) but recent studies have challenged this belief. The risk, even if present, is very low. Animal studies have shown that rodents exposed to megadoses of the medicine may develop an unusual form of thyroid cancer (called “medullary thyroid cancer”) but this effect has not really been seen in either human or primate studies.

What are the side effects of these medications, especially for people who don’t use them for their intended purpose?

Kraftson: Individuals need appropriate screening to check for possible contraindications for use of the medications. In addition to being exposed to the medication risks, individuals who take the medication without proper medical supervision are at risk for several unintended consequences. 

If a proper pre-treatment assessment has not been completed, treatment can worsen an undiagnosed and/or undertreated eating disorder. This can lead to dangerous malnutrition and delay treatment for mental health issues.

It is also possible that unsupervised or improper use of the medications can lead to unhealthy weight loss. Partnership is needed to ensure that individuals stay well-nourished during the weight control process. Furthermore, individuals should want guidance to help them decide whether the risk-benefit ratio of using the medication is right for them. Additionally, use of the medication may necessitate dose adjustments of other medications and this requires medical supervision. 

The issue of these medications being used for weight loss is widespread, and is largely discussed when it comes to Hollywood. What kind of impact is celebrity influence having on this?

Kraftson: The intense interest regarding weight control therapies highlights that many individuals are struggling to achieve health and weight goals. 

Celebrity voices can add to the conversation by garnering attention to important issues. However, while someone else’s health story can provide motivation and inspiration, it should not take the place of a thorough medical assessment and individualized treatment plan. 

Furthermore, we do not want the public discourse to be about ‘vanity use’. We want there to be recognition of obesity as a complex, multifaceted, chronic condition that may require specialized treatment tools - including medications - in addition to lifestyle efforts.

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