A new AI framework called MouseMapper allows scientists to examine disease-related changes across the entire body at cellular resolution. Obesity does much more than affect metabolism and fat storage. It also changes immune activity, nerve structure, and tissue organization throughout the body, raising the risk of conditions such as type 2 diabetes, cardiovascular disease, stroke, [...]
In a groundbreaking advancement in metabolic medicine, researchers at the Medical University of Vienna have utilized an innovative whole-body positron emission tomography/computed tomography (PET/CT) imaging framework to reveal the extensive metabolic transformation triggered by bariatric surgery. This state-of-the-art imaging technique, employing radiolabeled glucose analog [18F]fluorodeoxyglucose (18F-FDG), has illuminated the profound metabolic remodeling across numerous organs, offering unparalleled insights into how bariatric surgery reshapes the body’s internal metabolic landscape beyond mere weight loss.
For decades, bariatric surgery has served as a cornerstone treatment for obesity, delivering sustained weight reduction and mitigating related comorbidities such as diabetes and cardiovascular disease. However, until now, the precise systemic metabolic changes induced by these surgical interventions remained largely elusive. The advent of this novel PET/CT-based investigative approach addresses this gap by simultaneously quantifying metabolic activity across a broad spectrum of tissues, highlighting coordinated organ responses that contribute to metabolic recovery.
The study retrospectively analyzed 32 individuals diagnosed with obesity, who underwent either laparoscopic sleeve gastrectomy or one-anastomosis gastric bypass—a pair of commonly employed bariatric procedures. Whole-body 18F-FDG PET/CT scans were performed preoperatively and again at a 12-month postoperative interval. This design allowed for a comprehensive comparison of metabolic alterations in diverse tissues including subcutaneous and visceral adipose depots, liver, pancreas, spleen, adrenal glands, and skeletal muscle.
Quantitative analysis of 18F-FDG uptake demonstrated a significant decline in glucose metabolism within adipose tissue compartments—both subcutaneous and visceral—as well as in the liver, pancreas, and spleen. These reductions reflect diminishing metabolic stress and inflammatory activity, consistent with clinical improvements reported in patients’ glycemic control and lipid profiles. Intriguingly, skeletal muscle metabolism exhibited complex remodeling, potentially indicating enhanced insulin sensitivity and muscle functionality after weight loss surgery.
Perhaps most striking was the observation of an apparent increase in colonic volume at the 12-month mark, pointing to a potential compensatory adaptation in gastrointestinal anatomy and function. This expansion may influence nutrient absorption dynamics and warrants further investigation. Moreover, the network analysis of PET data revealed increased metabolic connectivity between different organs post-surgery, signifying a more synchronized, systemic metabolic state rather than isolated organ changes.
These multidimensional metabolic insights provide compelling evidence that bariatric surgery unleashes a holistic metabolic recalibration, underscoring the notion that organ systems adapt in concert to restore metabolic homeostasis. This data challenges the traditional focus on singular biomarkers and weight parameters by emphasizing integrative organ-level metrics that better capture the complexity of obesity treatment outcomes.
Clinicians stand to benefit immensely from these findings, as whole-body molecular imaging could serve as a vital tool for tailoring postoperative care. By visualizing metabolic recovery across multiple tissues, healthcare providers can optimize monitoring strategies, anticipate complications, and customize therapeutic interventions—transitioning from a one-size-fits-all paradigm toward truly personalized metabolic medicine.
While pharmacological advances, such as glucagon-like peptide 1 (GLP-1) receptor agonists, have recently gained prominence in managing obesity, many patients continue to elect bariatric surgery for its durable benefits and reduced reliance on chronic medication. The novel imaging approach described herein holds promise for enhancing the safety and efficacy of these surgical treatments by illuminating the intricate biological shifts occurring during the critical healing and adaptation periods.
From a technological perspective, relying on 18F-FDG PET/CT imaging leverages the high sensitivity of positron emission tomography combined with anatomical precision from computed tomography, enabling precise spatial localization and quantification of metabolic signals. This synergistic imaging modality opens pathways for broader applications beyond obesity, including the study of metabolic diseases, cancer metabolism, and aging.
The researchers emphasize that interpreting postoperative metabolic changes necessitates multifactorial analysis, integrating PET imaging results with comprehensive laboratory assessments of glycemic indices, lipid panels, endocrine markers, and inflammatory parameters. Such a multidisciplinary approach is essential to unravel the complex biochemical networks underpinning the observed structural and functional organ modifications.
Critically, this study’s longitudinal design allowed for the assessment of sustained metabolic impact one year following surgery, providing more reliable data on long-term physiological adaptation rather than transient postoperative fluctuations. The findings underscore the dynamic but persistent nature of the metabolic recalibration prompted by weight loss interventions.
This landmark research was detailed in Abstract 261206, titled “Evaluation of organic metabolic profiling alternation assessed by [18F]FDG PET/CT in obese patients before and after bariatric surgery,” and presented at the Society of Nuclear Medicine and Molecular Imaging’s 2026 Annual Meeting. The collaborative effort included experts in nuclear medicine, endocrinology, surgery, and biomedical imaging, reflecting the multidisciplinary challenges inherent in obesity treatment research.
In conclusion, this pioneering work spotlights the immense potential of whole-body PET/CT imaging as a transformative modality for understanding and optimizing metabolic health post-bariatric surgery. By mapping the metabolic trajectory across organ systems, clinicians and researchers gain a powerful vantage point to decipher obesity’s complex biology and tailor interventions for maximal therapeutic benefit. This integrated imaging strategy heralds a new era in metabolic medicine, one where precision and personalization drive superior patient outcomes across diverse obesity phenotypes.
Subject of Research: Metabolic changes and organ-level remodeling after bariatric surgery assessed by whole-body 18F-FDG PET/CT imaging.
Article Title: Evaluation of organic metabolic profiling alternation assessed by [18F]FDG PET/CT in obese patients before and after bariatric surgery.
News Publication Date: Not explicitly provided; related to Society of Nuclear Medicine and Molecular Imaging 2026 Annual Meeting.
Web References:
Image Credits: Courtesy of Society of Nuclear Medicine and Molecular Imaging (SNMMI).
Keywords: bariatric surgery, 18F-FDG PET/CT, metabolic imaging, obesity, organ metabolism, molecular imaging, personalized medicine, laparoscopic sleeve gastrectomy, one-anastomosis gastric bypass, metabolic remodeling, glucose metabolism, multimodal imaging.
In recent years, the medical community has begun to critically reassess the longstanding reliance on Body Mass Index (BMI) as the primary tool for evaluating obesity and its associated health risks. Despite its widespread use as a simple and accessible measure, BMI fails to distinguish between muscle mass, bone density, and actual body fat. This inability to account for fat distribution and composition means that a substantial portion of individuals with potentially serious obesity-related complications may slip through the conventional screening process undetected. Now, groundbreaking research from Keck Medicine of USC challenges the adequacy of BMI by introducing clinical obesity as a more precise and meaningful metric for identifying at-risk individuals.
Traditional calculations of BMI classify individuals based solely on the ratio of their weight to height, typically categorizing those with a BMI under 18.5 as underweight, between 18.5 and 25 as normal or healthy weight, between 25 and 29.9 as overweight, and 30 or above as obese. However, this methodology overlooks a crucial factor integral to metabolic health: the location and nature of adipose tissue. BMI’s inability to differentiate between lean muscle and fat means that muscular individuals might be labeled obese, whereas normal-weight individuals with excessive visceral fat remain unrecognized as having clinically significant obesity.
The concept of clinical obesity, developed in 2025 by the Lancet Diabetes and Endocrinology Commission, directly addresses the shortcomings of BMI by focusing on visceral fat accumulation, particularly in the abdominal region. Unlike subcutaneous fat, which lies just beneath the skin, visceral adipose tissue infiltrates deep within the abdominal cavity, surrounding vital organs and releasing inflammatory mediators that contribute to metabolic dysfunction and chronic disease. This inflammation plays a pivotal role in the pathogenesis of insulin resistance, cardiovascular disease, and other obesity-related morbidities.
Measurement of clinical obesity involves three key anthropometric parameters: waist circumference, waist-to-hip ratio, and waist-to-height ratio. These metrics provide a more nuanced assessment of fat distribution, enabling clinicians to detect dangerous levels of abdominal adiposity. If an individual exceeds established thresholds in at least two of these measurements and exhibits health impairments commonly linked to excess visceral fat—such as hypertension, diabetes, or joint pain—they are classified as clinically obese, regardless of their BMI category.
A new study led by hepatologist and liver transplant specialist Dr. Brian P. Lee, MD, MAS, and published in the Annals of Internal Medicine, systematically analyzed data from 5,600 adults aged approximately 49 years in the National Health and Nutrition Examination Survey (NHANES). Their findings unequivocally highlight the limitations of BMI: an estimated 26% of individuals categorized as having a normal BMI by conventional standards are, in fact, clinically obese. Furthermore, half of those classified as overweight by BMI also meet criteria for clinical obesity, underscoring the vast underdiagnosis potential inherent in BMI screening.
This underrecognition poses serious implications for public health and clinical practice. Presently, many treatment protocols, including pharmacologic and surgical options for obesity, are contingent upon BMI thresholds, inadvertently excluding millions who suffer the metabolic consequences of fat deposition despite “normal” weight status. Dr. Lee emphasizes that this gap means patients with normal or slightly elevated BMI values may miss timely interventions that could prevent progression to severe disease states.
The distinguishing capacity of clinical obesity to identify high-risk phenotypes that BMI overlooks is particularly vital given the wide spectrum of obesity-related diseases. Excess visceral fat is implicated in the etiology of type 2 diabetes, hypertension, dyslipidemia, nonalcoholic fatty liver disease (NAFLD), and certain malignancies. Moreover, chronic inflammation fueled by adipose tissue contributes to early vascular aging and organ dysfunction, making early detection a cornerstone for effective disease management.
Importantly, clinical obesity is not an inescapable destiny; it is a modifiable condition. Evidence-based interventions spanning lifestyle modifications, tailored pharmacotherapy, and in selected cases, bariatric surgery, have demonstrated effectiveness in reducing visceral fat and improving metabolic outcomes. However, success hinges on accurate diagnosis and stratification, areas where clinical obesity proves superior to BMI.
The compelling research results advocate for a paradigm shift in obesity screening and diagnosis. Dr. Lee envisions the integration of clinical obesity metrics into routine medical practice, augmenting current approaches. Doing so would refine risk assessments, enable personalized treatment pathways, and potentially reduce the incidence of obesity-related complications that represent a substantial burden on healthcare systems worldwide.
Furthermore, these insights challenge public perceptions of obesity, moving beyond the simplistic reliance on weight charts toward a more sophisticated understanding of metabolic health. The emphasis on adiposity rather than body weight alone could decrease stigma by reframing obesity as a complex biological condition rather than merely a cosmetic issue.
This evolving understanding also holds promise for advancing research into obesity pathophysiology. By employing clinical obesity criteria, studies can more accurately stratify participants, enhancing the validity of findings regarding interventions and outcomes. Such precision could drive innovation in therapeutics targeting visceral fat reduction and inflammation modulation.
In summary, the transition from BMI to clinical obesity assessment marks a critical evolution in the medical evaluation of obesity. The nuanced approach recognizes the heterogeneous nature of obesity and its metabolic consequences, advocating for improved diagnostic accuracy to ultimately enhance patient care and public health outcomes. Widespread adoption of this approach could redefine how clinicians worldwide identify and manage obesity, offering new hope for millions at risk of preventable disease.
Subject of Research: Evaluation of obesity measurement methods comparing Body Mass Index (BMI) and clinical obesity criteria.
Article Title: Limitations of BMI in Obesity Diagnosis: Clinical Obesity as a Superior Metric for Identifying At-Risk Individuals
News Publication Date: 2024
Web References:
Image Credits: PHOTO COURTESY OF BRIAN P. LEE, MD, MAS
Keywords: Body Mass Index, Clinical Obesity, Visceral Fat, Adipose Tissue, Obesity-Related Health Risks, Metabolic Syndrome, Waist Circumference, Waist-to-Hip Ratio, Waist-to-Height Ratio, Inflammation, Hepatology, Obesity Diagnosis
New research is challenging the longstanding reliance on body mass index (BMI) as the primary measure to define obesity and its health risks in adults. Traditionally, BMI—calculated as weight in kilograms divided by the square of height in meters—has been used as a simple and cost-effective metric to diagnose obesity. However, recent findings suggest this method may significantly underestimate the true prevalence of health risks related to excess body fat. By incorporating a broader set of anthropometric measurements combined with markers of obesity-related organ and physical dysfunction, scientists are painting a more complex and accurate picture of obesity’s impact on health.
The concept of “clinical obesity,” introduced by the Lancet Diabetes & Endocrinology Commission, aims to transcend the limitations of BMI alone by including assessments of body fat distribution and evidence of compromised organ or physical function. This approach attempts to address the disconnect between a normal or overweight BMI and the presence of metabolic and functional impairments caused by excess adiposity that BMI cannot detect. Anthropometric tools such as waist circumference, waist-to-hip ratio, and waist-to-height ratio provide critical insight into central adiposity—the fat deposited around vital organs—that BMI fails to quantify effectively.
Researchers at the University of Southern California led an analysis utilizing data from the 2021–2023 National Health and Nutrition Examination Survey (NHANES), a comprehensive and representative survey of the U.S. population. They examined over five thousand adults, evaluating their BMI, various anthropometric measures, and physiological indicators suggestive of reduced organ or physical function. The study’s cross-sectional design enabled the researchers to estimate how clinical obesity prevalence differs when relying on multifaceted criteria rather than isolated BMI cutoffs.
Remarkably, the data revealed that approximately one-quarter of adults classified within the normal BMI range exhibit clinical obesity—a condition characterized by excess adiposity coupled with early signs of organ or physical dysfunction. Furthermore, more than half of those categorized as overweight based solely on BMI met the clinical obesity criteria. These findings imply that a substantial subset of individuals presumed to be at lower risk according to BMI might actually bear significant health vulnerabilities associated with excess fat accumulation and its metabolic consequences.
When the threshold for defining excess adiposity included multiple abnormal anthropometric indicators rather than BMI alone, the prevalence of fat-related health risks soared dramatically. Nearly 78% of participants showed signs of excess adiposity when considering two or three abnormal anthropometric measures. This contrasts starkly with the roughly 41% prevalence when relying on an abnormal BMI combined with one anthropometric abnormality. The discrepancy underscores the utility of multi-parameter assessments in uncovering hidden health detriments not detected by BMI-focused screening.
These insights have profound implications for clinical practice. Physicians and health systems traditionally depend on BMI as a quick screening tool due to its simplicity and ease of use, but this research suggests that relying on BMI alone may overlook many patients at risk for obesity-related diseases. Introducing comprehensive assessments, including waist circumference and other anthropometric evaluations, paired with functional and organ health indicators, may improve diagnostic accuracy, enabling earlier intervention and more personalized care strategies.
From a pathophysiological perspective, the accumulation of visceral fat—fat stored in the abdominal cavity—plays a central role in driving metabolic syndrome, insulin resistance, type 2 diabetes, cardiovascular disease, and other complications frequently attributed to obesity. BMI lacks sensitivity to distinguish between subcutaneous fat, which lies beneath the skin, and the more dangerous visceral fat enveloping internal organs. This distinction is crucial, as excess visceral fat triggers inflammation, hormonal disruptions, and organ damage long before weight gain becomes apparent on conventional BMI scales.
Incorporating clinical obesity criteria can also better align treatment decisions with patients’ actual health status rather than simply their weight. It may steer healthcare providers towards recommending more intensive lifestyle interventions, pharmacotherapy, or monitoring in individuals who appear “normal weight” but harbor underlying fat-associated impairments. Conversely, it can prevent unnecessary alarm or overtreatment in those who have a high BMI by muscle mass or other benign factors, thus promoting more equitable and effective patient care.
The study’s findings support a growing consensus in the medical community that a paradigm shift is needed to improve obesity diagnosis and management. Public health initiatives and clinical guidelines must adapt to encompass multifactorial evaluations of adiposity and its systemic effects. Such evolution is vital not only to enhance patient outcomes but to curb the escalating economic and societal burdens imposed by obesity-related chronic diseases.
While BMI’s convenience and historical precedent have made it an entrenched tool in both research and clinical settings, this evidence calls for integrating additional anthropometric and functional parameters. The cost-effectiveness and feasibility of these measures in routine practice will need further evaluation but offer a promising avenue to identify hidden risk and tailor interventions more precisely.
This research thus adds a critical layer of understanding to the complex phenotype of obesity, highlighting how a seemingly normal weight individual might be clinically obese. Recognizing and validating clinical obesity as a diagnostic entity may revolutionize how medical professionals perceive, diagnose, and treat excess adiposity and its pervasive impact on human health.
As the obesity epidemic continues unabated worldwide, these findings emphasize the urgency of refining diagnostic tools beyond BMI. Embracing a more nuanced and comprehensive evaluation framework could empower clinicians to detect early declines in organ and physical function linked to excess fat, ultimately improving prevention strategies and reducing morbidity and mortality associated with obesity’s silent progression.
Together with the evolving insights into adiposity’s role in metabolic and cardiovascular diseases, adopting clinical obesity criteria marks a forward step in personalized medicine—one that respects the intricate interplay between body composition, function, and long-term health risks. Future research should expand upon these initial findings to develop standardized and accessible protocols that can be seamlessly integrated into diverse healthcare settings globally.
Subject of Research: People
Article Title: National Prevalence of Clinical Obesity by BMI Class: A National Cross-Sectional Study
News Publication Date: 2-Jun-2026
Web References: http://dx.doi.org/10.7326/ANNALS-25-05287
Keywords: Obesity, Clinical medicine, Body mass index
In a small clinical trial, researchers at the Ohio State University found that a tomato juice rich in lycopene and soy isoflavones lowered several proteins linked to chronic inflammation, raising hopes for food-based therapies.
The post Tomato-Soy Drink May Help Fight Chronic Inflammation in Adults with Obesity appeared first on Sci.News: Breaking Science News.
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