How the new generation of weight-loss drugs work
WEight bad medicine everywhere. It's hard to avoid gossip in the newspapers, on social media, or at the water cooler about how injections can help melt 10-20% of your body weight. The real news is being buried. These drugs offer a powerful new option for treating obesity, which is now widely accepted by doctors as a chronic disease. Being severely overweight increases a person's risk of diabetes, heart disease, stroke and 13 types of cancer. But evidence suggests that, for most people, dieting isn't an effective way to lose and maintain significant amounts of weight: The body resists trying to transfer more. How can new drugs help?
The history of diet pills is a sad one. In 1934, as many as 100,000 Americans used dinitrophenol to lose excess weight. It was poisonous and caused cataracts and occasionally death. An estimated 25,000 people have been blinded by the drug; it was banned for human use in 1938, but deaths continue today as people are still lured into buying it online. Amphetamines followed—until the risks of addiction and other side effects became apparent. Ephedra, an herbal remedy that was taken by an estimated 70,000 people in 1977, was also banned in the United States after it resulted in a death. Two other weight-loss drugs, rimonabant and sibutramine, have been discontinued due to safety concerns.
A new generation of weight-loss drugs that seem to be much safer were discovered by accident. They were developed to improve glucose regulation in people with diabetes, who have too much sugar in their blood. These drugs use short-chain amino acids to mimic the hormones your body naturally produces after a meal, but people with diabetes sometimes don't produce enough of the hormone.
The drugs semaglutide (sold as Wegovy) and tirzepatide (sold as Mounjaro) mimic the action of glucagon-like peptides-1 (GLP-1), one such hormone. This increases the production of insulin (which transports blood sugar to the cells of the body) and decreases the production of glucagon (which releases sugar from the liver into the blood). It also slows down the rate at which the stomach empties, which creates a feeling of fullness, which reduces appetite. In addition, the drug may increase energy expenditure by converting fat tissue into brown adipose tissue, which is more easily burned at rest. These effects not only help diabetics, but also promote weight loss.
There are disadvantages.side effects GLP-1 Medications include nausea and vomiting, and there is concern that they may increase a person's risk of developing a thyroid tumor. These drugs should certainly not be taken for cosmetic reasons. They may also need to be taken for life: when patients stop taking them, they regain most of the lost weight. And they are expensive.
But the potential benefits of these drugs go beyond their ability to promote weight loss in individuals. By showing that molecular mechanisms hinder people's attempts to lose weight, they show that binge eating is not to blame when people stay obese. This should slowly help remove the stigma. Bariatric surgery and medication are both useful tools in the fight against obesity. But by changing the subject, these new drugs may remind health system leaders that they need to do more to encourage healthy lifestyles.
Ultimately more action is needed because the problem is growing rapidly: according to the World Obesity Federation, more than half of the world's population will be overweight by 2035, up from 38 percent today, non-governmental organization. New Diet Drugs Represent a Turning Point in Obesity Treatment. But if governments want to reduce spending on medicines and surgery, they need to focus on preventing people from becoming obese in the first place. ■