Unique Energy Profile Associated with Persistent Thin Phenotype.

Area of Science:

• Endocrinology
• Metabolism
• Human Physiology

Background:

• Constitutional thinness, a physiologically determined underweight state, emerged in early 20th-century scientific literature.
• It presents a paradox: a healthy individual with normal intake resisting weight gain, distinct from anorexia nervosa.
• Despite its intriguing nature, research on constitutional thinness has been limited compared to obesity studies.

Purpose of the Study:

• To review current evidence on constitutional thinness, covering its definition, diagnosis, and underlying mechanisms.
• To explore the metabolic and physiological aspects of this persistent thin phenotype.
• To highlight the potential of studying constitutional thinness for understanding energy balance and identifying obesity-protective factors.

Main Methods:

• This review synthesizes existing scientific literature on constitutional thinness.
• It examines clinical studies, metabolic research, and physiological investigations.
• The focus is on evidence related to definition, diagnosis, and mechanisms.

Main Results:

• Constitutional thinness is characterized by a healthy state of persistent underweight resistant to weight gain.
• Metabolic and physiological mechanisms underlying this phenotype are complex and not fully understood.
• Limited research exists, hindering comprehensive understanding and clinical recognition.

Conclusions:

• Further research into constitutional thinness is crucial for medical and societal recognition.
• Understanding its mechanisms could provide valuable insights into energy balance and metabolism.
• Insights from constitutional thinness may offer protective metabolic patterns relevant to the global obesity pandemic.