Theories with varying gravitational constant G have been studied long time ago. Among them, the most promising candidates as alternatives of the standard general relativity are known as scalar–tensor theories. They provide consistent descriptions of the observed universe and arise as the low energy limit of several pictures of unified interactions. Therefore, an increasing interest on the astrophysical consequences of such theories has been sparked over the last few years. In this letter we comment on two methodological approaches to study evolution of astrophysical objects within a varying-G theory, and the particular results we have obtained for boson and white dwarf stars.Facultad de Ciencias Exactas