The thin fat paradox: Understanding normal weight obesity and its clinical relevance

Abstract

Obesity, defined by the World Health Organization (WHO) as an excess accumulation of body fat or body fat percentage (BFP) associated with clear health risks, presents a significant global challenge. While Body Mass Index (BMI) serves as a conventional metric for identifying obesity, it fails to account for body composition variations, such as distinguishing between fat-free mass and adipose tissue. Consequently, individuals with normal BMI may exhibit excessive body fat (BFP≥30%), termed Normal Weight Obesity (NWO). In contrast, others with normal BMI and normal body fat are termed Normal Weight Lean (NWL). NWO significantly elevates the risks of various metabolic disorders, including hyperglycemia, diabetes, hypertension, dyslipidemia, and reduced HDL levels. Moreover, NWO is associated with an increased risk of cardiovascular diseases (CVD), hypertension, low HDL, central obesity, and muscle weakness. Individuals with NWO face a heightened risk of developing cardiometabolic diseases, including atherosclerosis, coronary artery disease, stroke, and heart failure, due to the adverse effects of excess body fat on cardiovascular health. Furthermore, NWO is associated with insulin resistance, inflammation, and endothelial dysfunction, further exacerbating the risk of metabolic disorders and cardiovascular complications. Early identification of NWO is crucial for implementing preventive measures and lifestyle interventions to mitigate these health risks. Integrating body fat percentage measurements into nutritional screening protocols in healthcare facilities is essential for identifying individuals at risk of NWO and initiating appropriate interventions to prevent the onset of cardiometabolic diseases. This study aims to provide comprehensive insights into Normal-Weight Obesity (NWO) and its potential health implications.