A normal chow‐fed, ad libitum, circadian mutant mice (including mice with liver‐specific KO of Bmal1) developed some aspects of metabolic dysfunction that were exacerbated with age, while the time‐restricted feeding (TRF) prevented the whole‐body fat accumulation and serum hyperlipidemia, suggesting that TRF contributes to sustaining metabolic health in the condition of circadian rhythm/molecular clock defects such as Bmal1 deletion (Chaix et al., 2019). The gene discussed is BMAL1; the disease is hyperlipidemia.