The mean proportions of macronutrients consumed by bears in autumn were generally near that self‐selected by captive bears, which supports our hypothesis that the optimal diet preferences of bears coincide with the nutritional environment during the hyperphagic period due to the strong selective pressures associated with hibernation. For instance, there is a strong relationship between the body fat percentages of bears and their survival and reproductive capacity during hibernation (López‐Alfaro et al., 2013; Robbins, Meray, Fortin, & Lynne Nelson, 2012). In addition to behavioral adaptation, brown bears have acquired a suite of physiological adaptations facilitating adiposity while simultaneously remaining healthy (Rivet, Nelson, Vella, Jansen, & Robbins, 2017). Bears primarily gain lean mass, if any, during the spring season when their diets are higher in protein content (Hilderbrand et al., 1999; Swenson, Adamic, Huber, & Stokke, 2007). Yet, the importance of spring lean mass accrual should not be underestimated, as protein is transferred from mother to cub via milk during the hibernation period (López‐Alfaro et al., 2013).