WNT signaling plays a central role in the regulation of cellular growth and differentiation. In this issue of the JCI, Mori et al. link WNT signaling to the oxidative capacity of adipocytes during obesity. They show that secreted frizzled-related protein 5 is an extracellular matrix-residing protein that is highly induced during obesity and inhibits oxidative phosphorylation in a tissue-autonomous manner, possibly by sequestering WNT3a. These results implicate local WNT signaling as an attractive target for combating obesity.