The process of cellular transformation encompasses the acquisition of key and distinctive features, commonly known as hallmarks of cancer. These hallmarks are supported by tumor‐intrinsic molecular alterations, as well as changes in the microenvironment. Cellular metabolism represents one of the most intimate connections between a cell and the environment. In turn, metabolic adaptation is a research field of increasing interest in cancer biology. In this viewpoint, I will provide a panoramic perspective of the relevance and repercussions of metabolic alterations in tumors with nonexhaustive illustrative examples and I will speculate about the prospects of cancer metabolism research.