A macronutrient self‐selection study of captive brown bears found that they preferred a ratio of 17% protein to 83% nonprotein (carbohydrate + lipid) metabolizable energy (Erlenbach, Rode, Raubenheimer, & Robbins, 2014). The study provided strong evidence that this ratio is functionally significant, because compared with other dietary compositions it maximized mass gain (primarily fat mass) per unit energy intake, which is an important outcome for a hibernating mammal. Bears in that study preferred high‐lipid intake, but when confined to low‐fat diets would maintain the target ratio of protein to nonprotein energy by consuming carbohydrate.