An excessive food supply has resulted in an increasing prevalence of overweight and obesity, conditions accompanied by serious health problems. Several studies have confirmed the significant inverse correlation between testosterone and obesity. Indeed after decades of intense controversy, a consensus has emerged that androgens are important regulators of fat mass and distribution in mammals and that androgen status affects cellularity in vivo. The high correlation of testosterone levels with body composition and its contribution to the balance of lipid metabolism are also suggested by the fact that testosterone lowering is associated with important clinical disorders such as dyslipidemia, atherosclerosis, cardiovascular diseases, metabolic syndrome and diabetes. In contrast, testosterone supplementation therapy in hypogonadic men has been shown to improve the lipid profile by lowering cholesterol, blood sugar and insulin resistance. Leptin, ghrelin and adiponectin are some of the substances related to feeding as well as androgen regulation. Thus, complex and delicate mechanisms appear to link androgens with various tissues (liver, adipose tissue, muscles, coronary arteries and heart) and the subtle alteration of some of these interactions might be the cause of correlated diseases. This review underlines some aspects regarding the high correlations between testosterone physiology and body fat composition. Copyright © 2012 Wiley Periodicals, Inc.