With the number of individuals becoming overweight or obese, healthcare professionals are in need of accurate, reliable, and convenient tools to help personalize weight loss programs. Recently, a new indirect calorimeter (i.e. MedGem / BodyGem; aka “Gem”) was introduced as a convenient solution to determine resting metabolic rate (RMR) for assessment of daily energy needs. Several validation and comparison studies were conducted to determine if the Gem device is accurate and reliable. The purpose of this study was to conduct a systematic review of previous studies that evaluated the accuracy and reliability of the Gem devices.