Insulin and leptin oscillations license food-entrained browning and metabolic flexibility

Timed-feeding leads to adipose browning, although the integrative mechanisms for the same remain unclear. Here we show that twice-a-nocturnal (TAN) feeding causes biphasic oscillations of circulating insulin and leptin, representing their entrainment by timed-feeding. Insulin and leptin surges lead to marked cellular, functional and metabolic remodeling of sWAT resulting in increased energy expenditure. Single-cell RNAseq analyses and flow cytometry reveal a role for insulin and leptin surges in ILC2 recruitment and sWAT browning, since depleting leptin or blocking insulin receptor signaling or ILC2 cell recruitment, each dampens TAN feeding-induced sWAT remodeling and energy expenditure. Consistently, recreating insulin and leptin oscillations via once-a-day co-injections is sufficient to favorably remodel innervated sWAT. Indeed, innervation is necessary for sWAT remodeling since denervation of sWAT, but not BAT, blocks TAN-induced sWAT remodeling and resolution of inflammation. In sum, timed feeding reorganizes nutrient-sensitive pathways to remodel sWAT, which drives the metabolic benefits of timed-feeding.