Living organisms constantly face situations of feast and famine, and these changes in nutrient availability impact life traits as growth rate, stress resistance, fertility, and lifespan. Energy homeostasis mechanisms help to deal with changes in nutrient availability, adjusting development, growth, and reproduction. The maintenance of energy homeostasis in multicellular organisms relies on nutrient sensing pathways that signal in a cell non autonomous manner to coordinate growth and development across tissues. In our laboratory we use the postembryonic developmental programme of C. elegans as a model to study how nutrient sensing pathways control cell proliferation and arrest. We have a special focus in L1 arrest, a starvation-induced reversible arrest at the first larval stage. We use L1 arrest as a model to study the mechanisms involved in ageing and in maintenance of the proliferation potential during cell quiescence.