A model for stromal cell and tissue dynamics in early obesity. (A) Representations of quantity and proliferation frequency for resident ATMs, CD11c+ ATMs, and ATDCs (left Y axes), and adipocyte size (right Y axes). (B) An illustration of stromal cell and adipocyte dynamics, with two major phases dominating early obesity. Phase I encompasses rapid WAT expansion, resident ATM proliferation and ATDC infiltration. In Phase II, adipocyte stress at peak size cues ATM lipid accumulation and CD11c+ ATM recruitment.