Highly touted weight loss drugs prove that biology, not willpower, triggers obesity.

The brain establishes a "set point" that signals satiety. The higher the set point, the more a person eats until his brain said, "Enough." For people with obesity, that set point is higher on the dial than in a person with normal weight.

Ozempic and similar drugs such as Wegovy and Mounjaro work by lowering the brain's set point, the dial setting at which the brain tells the body that it's full. The brain is the body's chief chemist and can help regulate hunger and satiety by chemical reactions initiated by these powerful drugs.

The lower the set point, the less hungry a person becomes, and the less food is needed to feel full. The new set point lasts as long as a patient is on the drug, The Wall Street Journal reported. Patients who typically ate a lot before they started taking one of the drugs feel less hungry and fill up more quickly.

"This is not about willpower or personal choice," said Dr. Florence Halperin, an endocrinologist and chief medical officer at Form Health, an online medical weight loss clinic. "This is about your brain driving behaviors."

The drugs are providing new weapons in the battle against obesity. Nearly 42% of American adults have obesity, according to the Centers for Disease Control and Prevention. Obesity-related conditions include heart disease, stroke, type 2 diabetes, and certain types of cancer — the leading causes of preventable death.

The new medications have validated claims by those suffering from obesity that it's not their fault, said Dr. Louis Aronne, an obesity treatment specialist and professor of metabolic research at Weill Cornell Medical College.

The obesity epidemic is a product of forces, including a sedentary lifestyle and an abundance of cheap, processed foods that are high in calories, sugar, salt, and fat, said the Journal. Studies suggest these are addictive and can lead to obesity.

When one suffers from obesity, the brain's set-point system gets out of whack, said Dr. Lee Kaplan, director of the Obesity and Metabolism Institute in Boston. Obesity causes overeating, not the other way around, he said.

According to Healthline, Ozempic, along with drugs like Wegovy and Mounjaro, belongs to a class of medications called glucagon-like peptide 1 (GLP 1) agonists. They help the body manufacture more insulin, which helps lower blood sugar levels. They decrease appetite as well, so people tend to eat less food.

The drugs lower the set point by activating GLP-1 receptors in the hypothalamus and brain stem that regulate weight and appetite. The drugs also indirectly reach neurons in parts of the brain involved in reward sensations and impulse control.

When a patient reaches a new set point, some of their appetite returns and they are no longer feeling overfed, but the medications keep them at their new level. However, experts warn that when the drugs are stopped, the new set point no longer holds, and weight will be regained.

While these drugs are generally safe, they can cause gastrointestinal side effects such as bloating, vomiting, stomach pain, and feeling full early. Some people experience constipation or diarrhea, or new acid reflux symptoms and heartburn, said Healthline.