Thin Fat Obesity: The Tropical Phenotype of Obesity

Review
In: Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000.
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Excerpt

Disorders like diabetes and obesity have reached pandemic proportions globally. However, this problem is a little different in some tropical countries especially in the south Asian region. Countries like India and China have the leading number of people living with type 2 diabetes mellitus but paradoxically a much lower number of people with obesity (as defined by body mass index). This paradox is partly explained by the unique thin-fat phenotype prevalent in this region. Though this concept was described about 15 years ago, further evidence regarding its prevalence, pathophysiology, diagnosis, cardiometabolic risks, treatment, and implications for policy change are still emerging. The thin-fat phenotype is known by several other names in the scientific literature including normal weight obesity, metabolic obesity, metabolically unhealthy non-obese, etc. It is defined as an individual who has normal body weight (as measured by body mass index) but a disproportionately high body fat percentage (based on ethnicity and gender specific cutoffs). This phenotype is found to be very common in tropical countries and associated with a high cardiometabolic risk, which is similar to individuals with overt obesity. Moreover, the mortality associated with this phenotype is also significantly higher than nonobese subjects and thus this phenotype needs to be identified as a distinct entity. While evidence for the best therapeutic protocols is still emerging, an improvement in lifestyle intervention shows a slow but a positive trend in improving the cardiometabolic risk of this phenotype. The role of examining the underlying genetic makeup and the use of surrogate measures to estimate body fat could be useful adjuncts in the further characterization of this unique phenotype. In this chapter we summarize the current existing literature of this unique disorder and its importance in tropical countries. For complete coverage of all related areas of Endocrinology, please visit our on-line FREE web-text, WWW.ENDOTEXT.ORG.

Publication types

  • Review