A new study published by Dr. Yue Deng (ASU School of Engineering) and Dr. Barbara Scott (University of Nevada School of Medicine) compares resting metabolic rates calculated using predictive equations to metabolic rates measured using an indirect calorimeter.
The difference between the calculated and measured results was shown to be as high as 900 kCal/day. To put that into perspective, 900 kcal/day difference could explain a weight gain of 80 pounds in a year if the resting metabolic rate is not appropriately addressed with a measurement.
The full scientific study can be found here.