Provided is a method of preparing an orange peel ferment, an orange peel ferment obtained therefrom, and a method for reducing fat accumulation, sleep disturbance, and cancer risk. The orange peel ferment assists obese individuals to slim down via multiple mechanisms including reducing the fat content of adipocytes, promoting lysis of triglycerides in adipocytes, and enhancing the expression of genes involved in fat metabolism, and also reduces sleep disturbance through normalizing circadian rhythm and lowers cancer risk through suppressing expression of cancer risk genes.
