GLP-1s: Bridging the Evolution Gap in Modern Obesity

The global increase in average body weight is a biological response to an environment that has evolved faster than human genetics, according to Susan A. Jebb OBE, Professor of Diet and Population Health at Oxford University and Chair of the UK’s Food Standards Agency.

In an interview with Srijana Mitra Das at Times Evoke, published on April 5, 2026, Jebb stated that humans are currently fatter on average than at any other point in planetary history. This trend is driven by a misalignment between ancestral evolutionary adaptations and the conditions of modern life.

The Evolutionary Gap and Modernity

Humans evolved in environments characterized by food scarcity, where survival depended on working hard to secure nutrition. This evolutionary history left humans with genes that encourage eating freely whenever food is available to protect against future shortages.

In the modern era, these genetic predispositions are no longer advantageous. Jebb notes that for many people, food is now easily available, palatable and cheaper than it’s been in a historical sense, meaning individuals often have access to more food than their bodies require.

Simultaneously, physical activity levels have declined. The prevalence of gadgets and the nature of modern professional lives in middle- and high-income countries have led to increasingly sedentary lifestyles. Jebb explains that physical activity now requires a conscious effort to find opportunities, whereas energy requirements have dropped while food availability has surged.

Because of these factors, Jebb characterizes obesity as a perfectly normal response to what is quite an abnormal environment.

The Role of GLP-1 Medications

Glucagon-like peptide-1 (GLP-1) receptor agonists are emerging as a primary tool to address this biological gap. These medications are effective for individuals who are very overweight, including those who are not diabetic.

The medications function by mimicking the body’s natural hormones that signal satiety. By boosting these I’m full signals, the treatments lead patients to spontaneously reduce their food intake and lose weight.

Jebb suggests that the success of these drugs demonstrates that obesity is, in part, a biological phenomenon rather than solely a matter of willpower, as the pharmacological intervention directly influences the biological signals governing hunger and fullness.

The Evolution of Obesity Pharmacotherapy

The landscape of obesity management is continuing to shift toward more complex pharmacological interventions. Recent scholarly reviews and research indicate a transition toward multi-receptor agonists to improve treatment outcomes.

• GLP-1 receptor agonists (GLP-1 RAs) are currently reshaping treatment paradigms for obesity management.
• Research is moving toward unimolecular co-agonists, such as Amycretin, which acts as both a GLP-1 and amylin receptor agonist.

These next-generation pharmacotherapies aim to build upon the foundation of GLP-1 treatments by targeting multiple biological pathways simultaneously to manage weight and metabolic health.