The scientific paper on a revised definition of obesity was produced by the special Commission on Obesity. It appeared in The Lancet Diabetes & Endocrinology in 2025-1. The previously common practice by medical doctors was to classify person in the obesity category based mainly on the simple calculation of the body mass index (BMI = weight/height²). A BMI > 30 put persons into the obese category and stigma.
Since the Covid-19 society-wide testing experience, we are all familiar what it means if you get misclassified and have to live with the consequences (exclusion from work or events etc.). The simplifying and summarizing BMI calculation and classification has also produced many wrong classifications. For example, persons with a lot of muscles (just watch this at any fitness studio) will have a high weight relative to their body height², but they are likely to be more healthy than many other light weight, but seriously stressed persons.
In empirical test theory such cases are the so-called false positive cases, i.e. classified as obese, but not a medical problem at all. Medical doctors and health insurances should not finance special treatments for these persons, which foregoes treatment of other more needy persons.
With new expensive drugs on the market to treat obesity it is even more important to test with more precision the normal, pre-clinical and clinical status of obesity. Fatty tissue or muscles, that is the relevant question. Fatty tissue in muscles is the next level testing issue. 
Research Teaching Consulting