Aim Current Australian eating disorder guidelines recommend a “high” energy goal intake of 12 MJ/day, however, it is unclear whether a “high” energy goal is beneficial. This study aimed to investigate the impact of goal energy intakes <12 MJ/day (low energy) compared with ≥12 MJ/day (high energy) on body composition, midarm muscle circumference, frequency of medical complications, refeeding syndrome, length of stay, body mass index (BMI) and weight gain for patients with medically compromised eating disorders. Methods Five electronic databases (PubMed, CINAHL, Scopus, EMBASE and Web of Science) were searched in April, 2020. The certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation system. Results Four cohort studies were included (n = 656); three were rated positive and one neutral in terms of individual study bias. Evidence for the impact of higher and lower energy protocols on body fat percentage, midarm muscle circumference, frequency of medical complications, incidence of refeeding syndrome, length of stay, BMI and weight gain was of very low certainty. The certainty of evidence was downgraded to very low due to very serious risk of bias, inconsistency and imprecision. Conclusions This review found very low certainty of evidence to support the use of high energy goal intakes for patients with medically compromised eating disorders. More robust research is warranted to establish if there are clear clinical and psychological benefits of higher energy goal intakes.