PHOTO: Katarina Wolnik Vera
Text: Alejandra Misiolek and Janina Nagy
More and more people worldwide are suffering from obesity. On the one hand, this is the cause of emotional distress: Because of our beauty ideal of the slim, defined body, overweight people often feel discriminated against, stigmatized and devalued. On the other hand, being overweight also comes with a number of medical risks. For example, it increases the risk of diabetes mellitus, high blood pressure, heart attack, stroke and sleep apnea.
It is therefore not surprising that many people who are overweight try to lose weight. The market of weight loss products is booming: There are countless companies promising quick and easy weight loss and more and more medical drugs to help people lose weight. How do these drugs work and are their effects scientifically proven? And what are the health risks associated with them?
A recent article published in nature magazine  discusses certain medical drugs which are used to help with weight loss when a healthier diet and regular exercise aren’t enough. A study presented at the ObesityWeek conference in San Diego in November 2022 observed that the administration of semaglutide for 16 months in combination with lifestyle changes reduced body weight by at least 20% in one third of the teenagers studied. Similar effects had also been observed in adults before. Compared to previously existing methods and medications, these are astonishing results.
What are these drugs and how they work?
Semaglutide is now available as the drug Ozempic®, while a similar substance called liraglutide has already been in use under the name of Saxenda® for a few years.
The weight loss is probably caused by different mechanisms, such as delay in gastric emptying, increase in satiety, increase in resting energy expenditure, and direct effects of appetite centers in the brain. Both agents are glucagon-like peptide-1 (GLP-1) receptor agonists (meaning that these substances block the receptor GLP-1) and cause the body to produce more insulin.  It was approved firstly for type 2 diabetes treatments but scientists noticed that participants in clinical trials also lost weight, owing to GLP-1’s effect on receptors in the brain that govern appetite and those in the gut that slow digestion. Over time, companies began to trial these diabetes medications for weight loss.
This new generation of anti-obesity medication seems to have less of the serious side effects of previous drugs while still leading to significant weight loss (8-15% of body mass, according to most studies) without dieting. However, we still don’t know exactly how these substances work.
It is possible that in the near future an even more effective drug will be on the market for obesity, which in one study led to a 21% drop in body weight: tirzepatide. This substance was approved in 2022 for type 2 diabetes and targets another hormone in addition to the GLP-1 receptor, which is also involved in insulin secretion. Weight loss as with tirzepatide is normally only achievable through bariatric surgery.
Is the medication safe? What are side effects to bear in mind?
Although it has been approved by the FDA (approved for weight management in adults with body-mass index – BMI of 30 kg/m2 or higher, or those with BMI of 27 kg/m2 or higher with obesity-related comorbidities), it is only justified to use because the negative effects of obesity and/or diabetes surpass the negative effects of the medication itself. We need to remember that it is not an innocuous substance and that it can have different side effects in different people.
The most common side effects of this medication in adults include nausea, diarrhea, constipation, vomiting, injection site reaction, low blood sugar (hypoglycemia), headache, tiredness (fatigue), dizziness, stomach pain, and change in enzyme (lipase) levels in your blood. It can also augment the risk of thyroid cancer and of acute pancreatitis.
There is no set time limit for treatment with Saxenda®/Ozempic®, however, it should only be continued for longer than 12 weeks if there is a weight loss of 5% when used in conjunction with a calorie-controlled diet and regular exercise. If not, it is not being effective and given the side effects, it is better to stop.
Although these medications may help obese individuals lose weight, some questions remain.
Will people have to take the drugs for life to maintain their weight? For whom do these medications work well? For example, it seems that individuals with type 2 diabetes lose less weight than those without diabetes.
There is also a risk that people will start taking these drugs to lose weight without any medical indication.
What about the psychological risks?
As nearly 30% of people who are considered obese are metabolically healthy, some researchers are concerned that by offering a weight solution in societies that prize thinness, these drugs could also inadvertently reinforce the disputed link between excess weight and health. We shouldn´t pathologize a person’s health simply based on their body weight. There is risk that people will use these drugs mainly to escape weight stigma, rather than to serve a true health need and would consider it a “quick fix” or an easy way out of obesity.
And the cost?
Also, although there is plenty of demand, the cost of the drugs is very high so not everyone will have access to them (in Spain it oscillates between 300€ and 500€/month).
Although these are things to keep in mind, these “miraculous drugs” are helping many people lose weight already and more research is currently being done to further improve their effects and to really understand how they work.
1.Halawi, H., Khemani, D., Eckert, D., O’Neill, J., Kadouh, H., Grothe, K., … & Camilleri, M. (2017). Effects of liraglutide on weight, satiation, and gastric functions in obesity: a randomised, placebo-controlled pilot trial. The Lancet Gastroenterology & Hepatology, 2(12), 890-899.
2.Prillaman, M. (2023). The’breakthrough’obesity drugs that have stunned researchers. Nature, 613(7942), 16-18.