Background: To evaluate the methodological quality of (1) clinical practice guidelines (CPGs) that inform nutrition care in critically ill adults using the AGREE II tool and (2) CPG recommendations for determining energy expenditure using the AGREE-REX tool. Methods: CPGs by a professional society or academic group, intended to guide nutrition care in critically ill adults, that used a systematic literature search and rated the evidence were included. Four databases and grey literature were searched from January 2011 to 19 January 2022. Five investigators assessed the methodological quality of CPGs and recommendations specific to energy expenditure determination. Scaled domain scores were calculated for AGREE II and a scaled total score for AGREE-REX. Data are presented as medians (interquartile range). Results: Eleven CPGs were included. Highest scoring domains for AGREE II were clarity of presentation (82% [76–87%]) and scope and purpose (78% [66–83%]). Lowest scoring domains were applicability (37% [32–42%]) and stakeholder involvement (46% [33–51%]). Eight (73%) CPGs provided recommendations relating to energy expenditure determination; scores were low overall (37% [36–40%]) and across individual domains. Conclusions: Nutrition CPGs for critically ill patients are developed using systematic methods but lack engagement with key stakeholders and guidance to support application. The quality of energy expenditure determination recommendations is low.