We hypothesized that individual differences in prioritization of dairy cows exposed to feed restrictions (FR) are associated with feed efficiency. The objective was to explore clustered associations among adaptive responses to experimental FR and metrics of feed efficiency. 16 Holstein and 17 Montbéliarde cows, starting at 87±6DIM, underwent four 4d FR periods (50% of individual NEL). Cows were fed ad libitum after FR1 (during 10d), and FR2, FR3, FR4 (during 3d). Energy-corrected milk yield (ECMY), plasma nonesterified fatty acids (NEFA) and bilirubin concentrations were measured prior, during and after FR. Residual feed intake (RFI) and milk energy conversion efficiency (ECE) were calculated in early and mid-lactation. Individual ECMY pre-FR, and integrated areas under the curve during FR (AUC1) and recovery (AUC2) were calculated and clustered separately for FR1 (or challenge 1, CH1) and the sum of AUC responses during FR2 through FR4 (CH2). Then cluster (CL) differences were tested for RFI and ECE. For both CH1 and CH2, 3 distinct CL, each composed of both breeds, emerged: CL1 with low ECMY pre-FR, low ECMY AUC1 and ECMY AUC2, and low NEFA AUC response; CL2 with high ECMY pre-FR, average ECMY AUC1 and better ECMY recovery in terms of AUC2; and CL3 with high ECMY in pre-FR, high ECMY AUC1 and AUC2, and low bilirubin. RFIearly was numerically higher for cows in CL3-CH1. A concordant effect occurred for CL3-CH2 in terms of ECEearly, where the low mobilization of body reserves may be explained by better feed efficiency to support lactation. 50% of cows changed CL typology between CH1 and CH2, suggesting that individual adaptation mechanisms are impacted when cows face multiple challenges. In conclusion, feed efficiency seems to have buffered the lower body reserves mobilization of a subgroup of cows during FR, in order to support lactation.