Can genotype be used to tailor treatment of obesity? State of the art and guidelines for future studies and applications.

ABSTRACT

Current treatments for losing weight based mainly on diet and exercise are, in general, unsuccessful. So, as an alternative to the general strategy of one-size-fits-all, a more individualized approach is proposed through the so-called Personalised Medicine in which genotype data are used to personalize treatment and to optimize the results. This paper examines the current situation of the evidence on the influence of the genotype in modulating the association between diet or exercise on obesity and weight-related measures. Most of these studies are observational studies, as there are far fewer experimental ones assessing short-term weight-loss or its long-term maintenance. Many more studies are therefore required for that purpose. Having reviewed the results of the studies undertaken to date, we can say that huge progress has been made in identifying polymorphisms in genes related with obesity and that there is a great consistency of the influence of the FTO gene on the same, while for other variants, there is less consistency. Moreover, the results on gene-diet and gene-physical activity interactions in determining obesity phenotypes are very heterogeneous, so an important recommendation is to standardize the methodology for undertaking these studies. Furthermore, an important lack of replication has been observed suggesting undetected higher-level interactions and/or experimental caveats. Therefore, the current evidence level of applying genotype data to obesity treatment is at its early stages. Nevertheless, future prospects are encouraging and to make this come true, several guidelines are proposed for carrying out new studies on applications in clinical practice.