Obesity Pathogenesis: An Endocrine Society Scientific Statement

Area of Science:

• Physiology
• Endocrinology
• Public Health

Background:

• Obesity is a prevalent, costly global chronic disorder affecting one-third of US adults and contributing significantly to mortality.
• Effective long-term weight reduction strategies are lacking, as individuals often regain lost weight after completing programs.
• Obesity disproportionately affects lower-income groups and is increasingly prevalent in children and adults.

Purpose of the Study:

• To assess current knowledge on the mechanisms of excess body fat accumulation and weight regain.
• To emphasize the science of energy homeostasis as a central factor in weight stability.
• To elucidate the pathogenesis of obesity by understanding genetic, developmental, and environmental influences on energy homeostasis.

Main Methods:

• Review of basic science, clinical, and epidemiological literature.
• Analysis of evidence related to energy homeostasis and body fat regulation.
• Focus on mechanisms underlying the "upward setting" of defended body fat mass.

Main Results:

• Growing evidence indicates obesity is a disorder of the energy homeostasis system, not passive weight gain.
• Understanding the biological defense of excess fat mass is crucial.
• Weight regain after loss is a significant challenge linked to homeostasis disruption.

Conclusions:

• Obesity is a complex disorder of energy homeostasis, requiring a deeper understanding of its underlying mechanisms.
• Elucidating obesity pathogenesis is essential for improving treatment, public policy, and awareness.
• Further research into genetic, developmental, and environmental factors influencing energy homeostasis is critical for addressing the obesity epidemic.