Key factors involved in obesity development.

Obesity has been considered to be a chronic disease that requires medical prevention and treatment. Intriguingly, many factors, including adipose tissue dysfunction, mitochondrial dysfunction, alterations in the muscle fiber phenotype and in the gut microbiota composition, have been identified to be involved in the development of obesity and its associated metabolic disorders (in particular type 2 diabetes mellitus). In this narrative review, we will discuss our current understanding of the relationships of these factors and obesity development, and provide a summary of potential treatments to manage obesity. Level of Evidence Level V, narrative review.