Obesity and mental health are serious and prevalent public health concerns worldwide. The study had the purpose of discovering what are the confounding risk factors in the link between obesity and depression. What is the current methodological approach to treat/prevent obesity and depression? How can the interventions be meaningfully improved? Observational data have shown inconsistent results with highly varying differences with regards to gender and country of conduct of the study. The physiological mechanism could not explain the differences among countries which were later clarified by sociological factors, especially by culture and level of obesity stigmatization differences among the countries. The interventional studies were found to be lacking in their methodology as regards to the lack of follow-up and absence of interventions with a joint focus on treating both obesity and depression. As obesity and depression were tackled separately with the purpose of treating the outcome rather than the risk factor, most interventions are deemed by this study insufficient as they can only offer short-term healthrelated relief and quality of life. If the exposure from the risk factor, be it stress, social stigma or socio-economic status, etc. is not dealt with first, it is very likely for either depression/obesity to return on a long-term basis and continue the vicious bi-directional cycle of obesity and depression. The conclusion of the study is that the approach in treatment should be jointly tackling both obesity and depression and that it should be done in a heavily personalized manner. In the future, a standardized method to identify the various underlying risk factors should be created, for example through a multidisciplinary approach via questionnaires alongside laboratory examination.