The issue of optimal energy delivery in critical care patients is a matter of debate, and guidelines recommend to base energy prescriptions on measured energy expenditure (EE). Recently, the largest study ever (n = 1171 patients) of the relation between energy and protein delivery, measured EE, and outcome was published [1]. The authors should be commended for this contribution, particularly for confirming the importance of proteins to outcome. Nevertheless, although they tried “to reduce any possible bias caused by short stay” by including in the analysis only patients staying >96 h, the interpretation of their results was probably contaminated by short stayers, as the median reported length of stay was 5 days.