Weight loss can be a frustrating journey for many individuals, especially when they see their peers achieving significant results with the help of popular new weight-loss drugs like Wegovy and Zepbound. Despite adhering to the medication’s instructions diligently, some people find themselves in a category known as “nonresponders,” where they fail to lose a substantial amount of weight. This phenomenon has left many feeling like failures, even though the drugs are likely not within their direct control.
Research has shown that up to one in four people taking GLP-1 receptor agonists for weight loss are nonresponders, defined as those who lose less than 5 percent of their body weight after three months of treatment. Clinical trials have revealed that as many as 23 percent of individuals fall into this category, regardless of the dosage of the medication. Scientists believe that the varying responses to these drugs may be linked to the underlying biology of each individual.
Obesity is a complex condition influenced by a combination of genetic, environmental, biological, and behavioral factors. Researchers have identified four distinct biological phenotypes that may impact how individuals respond to weight-loss drugs. For example, some people have a “hungry brain” phenotype, requiring a higher calorie intake to feel full, while others have a “hungry gut” phenotype, feeling full quickly but becoming hungry again soon after. Genetic variations play a significant role in determining these phenotypes and how individuals respond to different medications.
Studies have also explored specific genes, such as neurobeachin, that may influence an individual’s response to GLP-1 drugs. Variations in this gene can affect the efficiency of an enzyme called protein kinase A, which regulates appetite suppression in the hypothalamus. Additionally, research has suggested that genetic differences in GLP-1 receptors themselves may be linked to drug responsiveness.
While genetic explanations for individual responses to weight-loss drugs have shown inconsistent results, researchers continue to investigate ways to predict treatment outcomes more accurately. The development of genetic scores to determine who may respond best to specific treatments could potentially save individuals time and money. However, environmental and lifestyle factors will always play a crucial role in weight loss success.
In conclusion, the journey to weight loss is unique for each individual, and factors beyond genetics can influence treatment outcomes. While advancements in genetic research may offer insights into personalized weight-loss strategies, it is essential to remember that lifestyle choices and environmental factors also play a significant role in achieving long-term success.

