Recent research indicates that residual feed intake (RFI) may not be related to efficiency of energy use, but few results have been published for other feed efficiency traits. The current objective was to determine the relationships of different measures of feed efficiency with indicators of energy expenditure at constant feed intake. Five performance trials were conducted to measure feed intake, growth and heart rate (HR) or heat production in growing cattle. Feed efficiency traits included those where a lesser value is more efficient [feed conversion ratio (FCR), RFI, RFI adjusted for fat composition (RFIc), RFI from model predicted feed intake (RFIm)] and those where a greater value is more efficient [partial efficiency of growth, residual gain efficiency (RGE), and residual intake and gain (RIG), which is combination of RFI and RGE]. Heart rate alone or heat production (heart rate × oxygen pulse) was measured following the performance trial. Trials 1, 3, 4 and 5 included 39 Angus bulls and heifers, 119 Brangus heifers, 115 Brangus heifers, and 45 Angus heifers fed high-roughage diets with heart rate measured on 39 animals at fasting, 16 heifers at 1.1× expected maintenance requirement (MEm), 16 heifers restricted-fed at120 g DM/kg^.75, and 16 heifers at 1× expected MEm, respectively. Trial 2 included 56 Angus bulls and heifers fed a high-concentrate diet with heart rate measured on 12 bulls and 12 heifers at 1.1× expected MEm. Phenotypic correlations of feed efficiency traits with DMI and ADG were similar to published studies. Phenotypic correlations of feed efficiency traits with fasting HR in Trial 1, maintenance HR in Trial 2 and 3, and restricted-intake HR in Trial 4 were not significant. In Trial 5, FCR (−0.62), RFI (−0.56), RGE (0.60), RFIc (−0.60), RFIm (−0.60), and RIG (0.65) had strong phenotypic correlations with maintenance heat production such that more efficient heifers had greater maintenance heat production. These data indicate that proposed traits to select for improved feed efficiency have no or an inverse relationship with energy expenditure when growing cattle are fed at constant feed intake.