A new approach to defining obesity could help physicians better determine which patients need more intensive treatment by focusing on the effects of excess adiposity on organs and tissues rather than relying primarily on whether a person meets a set of metabolic risk thresholds, according to researchers from LSU's Pennington Biomedical Research Center in a review published July 31.
The review, published in The Journal of Clinical Endocrinology & Metabolism, examines the concept of "metabolically healthy obesity" and argues that a newer framework distinguishing preclinical obesity from clinical obesity provides a more biologically grounded and clinically actionable approach. The paper, titled "Does Metabolically Healthy Obesity Really Exist: Going Toward New Definitions," was authored by Dr. Christian Rodriguez and Dr. Eric Ravussin.
The traditional classification system distinguishes between metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO), typically based on the presence or absence of metabolic abnormalities. Under this model, individuals with MUO may be considered for more intensive interventions while those with MHO may initially receive structured lifestyle support. However, definitions for MHO vary across studies and are often unstable over time.
"Metabolically healthy obesity helped researchers recognize that obesity does not affect every person in exactly the same way," Ravussin said. "But the classification is difficult to use as a foundation for long-term treatment because the definitions vary and metabolic health can change. A person who is considered metabolically healthy today may not be metabolically healthy tomorrow."
The proposed preclinical/clinical framework instead defines preclinical obesity as excess adiposity without current evidence of organ or tissue dysfunction, recommending structured lifestyle interventions and regular monitoring for these individuals. Clinical obesity is defined by excess adiposity accompanied by organ or tissue dysfunction or significant limitations in daily activities; these cases may warrant pharmacotherapy or surgery alongside other treatments.
"Moving from the question, 'Is this person metabolically healthy or unhealthy?' to 'Is excess adiposity affecting the function of the body?' gives us a more clinically meaningful way to think about obesity," Rodriguez said.
The authors state that further research will be needed to validate diagnostic criteria for this evolving framework before it can be consistently implemented in clinical practice.
