Pubertal timing is the result of the operation of a finely orchestrated neuroendocrine network that senses and integrates a wide array of signals from the internal milieu and the external environment. Among them, the nutritional status and the amount of energy reserves of the organism are especially prominent. Indeed, conditions of metabolic stress have been associated with alterations in pubertal timing in preclinical animal models and humans; a phenomenon that not only affects the reproductive axis itself but may also impact other bodily functions. The clinical implications of these alterations highlight the need for a better understanding of the metabolic control of puberty and the pathophysiological mechanisms of pubertal disorders linked to metabolic unbalance, from malnutrition to obesity. In this chapter, we provide an updated overview of relevant metabolic hormones, neuropeptide systems, cellular networks, and molecular mediators that crucially participate in the tight bounding between body energy balance and pubertal development.