Autophagy is a catabolic pathway whereby the cells self-digest proteins and intracellular organelles. It is an evolutionarily conserved, genetically controlled process that starts with a membrane nucleation in the cytoplasm. The membrane elongates around its cargo until the edges fuse forming an autophagosome. The autophagosome fuses with a lysosome allowing the lysosomal hydrolases to degrade the content to building blocks that can be re-used for de novo synthesis of macromolecules or ATP generation. Thus, autophagy serves as a temporary survival mechanism during periods of starvation both in a single-cell and in a whole organism. In addition to starvation numerous stresses, such as anti-cancer treatment, hypoxia, growth factor withdrawal, bacterial infection activates autophagy above the low basal level. In unstressed cells autophagy is kept down by mTORC1 which regulates cell growth and protein synthesis in response to nutrient and growth factor availability. In starved cells LKB1 activates AMPK that inhibits mTORC1 via a pathway involving TSC1/2 and its substrate Rheb. We recently showed that AMPK inhibits mTORC1 and induces autophagy also in non-starved cells. Various calcium mobilizing agents and cytokines activated AMPK via activation of CaMKK-beta or TAK-1, respectively, resulting in inhibition of mTORC1 even in nutrient rich conditions. Thus, we suggest that AMPK is a more general regulator of autophagy than previously expected.