New examine on weight problems standards exhibits: overwhelming majority of affected people are categorized as clinically overweight

An worldwide analysis group has examined how many individuals are affected by preclinical and scientific weight problems and what well being dangers are related to this. The group led by Prof. Matthias Schulze from the German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE) found that the majority individuals with weight problems, i.e., a physique mass index (BMI) of at the least 30 kg/m², exhibit different measurable indications of elevated physique fats mass and that round 80 p.c of affected people are already experiencing health-related problems. The outcomes have been revealed within the specialist journal Nature Communications.

New Definition of Obesity

The World Health Organization (WHO) has lengthy categorized weight problems as a illness. Nevertheless, it’s disputed whether or not weight problems is really an unbiased illness or reasonably a threat issue for different ailments. 

In early 2025, a world fee launched by The Lancet Diabetes & Endocrinology proposed classifying weight problems into two classes: Preclinical and scientific weight problems. According to this idea, weight problems must be confirmed by at the least one different anthropometric criterion, akin to waist circumference or physique fats content material, along with BMI. Furthermore, individuals with identified weight problems who additionally present obesity-related abnormalities, akin to hypertension or issues of glucose and lipid metabolism, must be categorized as having scientific weight problems, and other people with out these abnormalities as having preclinical weight problems. The fee proposes classifying scientific weight problems as an unbiased illness with corresponding remedy indications.

Evaluation of Large Population and Interventional Studies

Against this backdrop, scientists from the German Center for Diabetes Research (DZD), DIfE, and the University Hospital Tübingen have explored how incessantly preclinical and scientific weight problems happen within the inhabitants, whether or not affected people have an elevated threat of kind 2 diabetes and heart problems, and whether or not a life-style intervention can cut back the prevalence of scientific weight problems. To accomplish that, the researchers evaluated the info from three main research: The National Health and Nutrition Examination Survey (NHANES; consultant of the U.S. Population), the European Prospective Investigation into Cancer and Nutrition (EPIC) Potsdam Study, and the Tuebingen Lifestyle Intervention Program (TULIP).

Differences in Risk: Preclinical versus Clinical Obesity

In the method, it was demonstrated that 100% of individuals with a BMI equal to or better than 30 kg/m² may very well be confirmed as having weight problems based mostly on at the least one different anthropometric criterion. Furthermore, round 80 p.c met the factors for scientific weight problems. 

People with scientific weight problems had an roughly 3-times increased threat of heart problems and a roughly 8-times increased threat of kind 2 diabetes in contrast with individuals who would not have weight problems and don’t meet the scientific standards. In distinction, individuals with preclinical weight problems didn’t exhibit an elevated threat of heart problems however nonetheless had an elevated threat of kind 2 diabetes. 

A nine-month way of life intervention within the TULIP examine lowered the speed of scientific weight problems from 71 to 57 p.c and the speed of prediabetes from 52 to 29 p.c. The scientists decided that blood strain, triglyceride ranges, and blood sugar regulation had been notably improved by the intervention. “This is an important prerequisite for possible prevention strategies in this context,” explains Prof. Norbert Stefan from the University Hospital Tübingen. How effectively individuals reply to a life-style program seems to be depending on age and liver fats content material, amongst different issues.

Additional Diagnostic Steps Are Not Always Necessary

“Our results provide a solid data basis for evaluating this newly proposed definition,” says first writer Dr. Catarina Schiborn from DIfE. “We had been capable of exhibit that an extra affirmation of weight problems by means of additional anthropometric measurements akin to waist circumference or physique fats content material, as proposed by the fee as a primary diagnostic step, doesn’t seem like mandatory in follow, as they had been met by just about all members with a BMI-based weight problems standing. In this regard, additional refinement of those extra standards is required.“ 

Furthermore, lower than 20 p.c of individuals with confirmed weight problems can be thought-about preclinical. Most individuals with weight problems already exhibit measurable well being impairments and are subsequently categorized as having scientific weight problems. “We also observed that many clinical criteria strongly overlap,” provides Prof. Matthias Schulze, head of the Department of Molecular Epidemiology at DIfE. “This raises the query of whether or not such a complete prognosis course of for the classification of preclinical and scientific weight problems is definitely mandatory.“

In additional research, the researchers wish to examine the brand new standards with already established ideas akin to “metabolically healthy” versus “metabolically unhealthy“ weight problems. 

Backround Information: 
 

Obesity was first acknowledged as a illness by the WHO in 1948, and extra lately additionally by a number of medical societies and nations. The present International Classification of Diseases (ICD) revealed by the WHO defines weight problems as a “power complicated illness“ and assigns it a selected code (5B81). Nevertheless, it’s disputed whether or not weight problems is really an unbiased illness or reasonably a threat issue for different ailments.

Advocates say:
If weight problems is formally acknowledged as a illness, affected people would have higher entry to medical help. It might additionally assist to eradicate prejudice and stigma.

Critics warn:
A blanket definition of weight problems as a illness might diminish private accountability. Moreover, not all individuals with obese are unhealthy. The frequent measurement of BMI says little in regards to the particular person’s precise well being standing. Such a classification might result in overdiagnosis—with pointless remedy, surgical procedure, and excessive prices.

The core difficulty is:
The particular sickness brought on by weight problems itself has not but been clearly outlined. In most instances, it’s merely thought to be a set off for different ailments (e.g., kind 2 diabetes, heart problems), reasonably than as a illness with distinct signs. It subsequently lacks a transparent medical identification.

In addition, obese can have very wide-ranging causes and meanings, generally even being labeled as a symptom of different ailments. The present definition of weight problems is subsequently typically imprecise for medical selections.

At the identical time, this lack of readability implies that many affected people obtain no remedy as a result of they “have but developed a secondary situation“—regardless that their physique is already impaired by the obese.

The new prognosis standards proposed by the Lancet professional fee are meant to enhance the evaluation of weight problems in on a regular basis medical follow—not solely with regard to body weight, but in addition particular well being impairments in areas akin to respiration, metabolism, the cardiovascular system, organ programs (e.g., liver and kidneys), or the musculoskeletal system. If obese has already triggered measurable injury to organs and tissues, the fee defines it as “clinical obesity.” Without such restrictions, weight problems is taken into account “preclinical.”

Such a brand new understanding might:

• permit for extra equitable medical care,
• help higher political decision-making,
• and enhance social attitudes to weight problems.

Further Information

Rubino, F. et al.: Definition and diagnostic criteria of clinical obesity. Lancet Diabetes Endocrinol. 13(3), 221-262 (2025). [Open Access]

Publication

Schiborn, C., Hu, F., Stefan, N., Schulze, M.: Preclinical and clinical obesity: prevalence, associations to cardiometabolic risk and response to lifestyle intervention in NHANES and the EPIC-Potsdam and TULIP studies. Nature Commun. 17, 1935 (2026). [Open Access]

Further Publications

Schulze, M. B., Stefan, N.: Metabolically healthy obesity: from epidemiology and mechanisms to clinical implications. Nat. Rev. Endocrinol. 20, 633–646 (2024). [Open Access]

Stefan, N., Schulze, M. B.: Metabolic health and cardiometabolic risk clusters: implications for prediction, prevention, and treatment. Lancet Diabetes Endocrinol. 11(6), 426-440 (2023). 

Zembic, A., Eckel, N., Stefan, N., Baudry, J., Schulze, M. B.: An Empirically Derived Definition of Metabolically Healthy Obesity Based on Risk of Cardiovascular and Total Mortality. JAMA Netw. Open 4(5), e218505 (2021). [Open Access]