Background The prevalence of obesity has increased worldwide in parallel with associated metabolic disturbances such as diabetes and non‐alcoholic fatty liver disease. Objective The objective of this article is to underscore discrepancies in the standard anthropometric cut‐off values and the presence of metabolic disturbances including diabetes and non‐alcoholic fatty liver disease caused by biological and ethnic variations. Materials and methods We performed a literature review regarding the diagnosis and prevalence of obesity, diabetes, metabolic syndrome and non‐alcoholic fatty liver disease and about the different available indicators to define obesity. Results There is an ongoing epidemic of these chronic diseases, partially attributed to the increased prevalence of obesity. The available markers to indicate adiposity are imperfect, and the selection of accurate cut‐off points is still not clear. Conclusion Methods to quantify adiposity that are useful in clinical practice should be developed to better classify individuals and to reflect metabolic risk more appropriately.