The optimal nutrition regimen for obese hospitalized patients remains controversial, and clinicians use a variety of different methods for estimating needs of obese patients who require nutrition support. Adjusted body weight has been proposed as one method to improve the accuracy of predictive equations when calculating calorie expenditure of obese patients. Although adjusted body weight has been criticized as a "nonscientific method," several studies have investigated the accuracy of adjusted body weight calculations and found it comparable or superior to several prediction equations. This article will summarize the results and discuss the limitations of data from studies regarding calculations for obese hospitalized patients. The use of adjusted body weight is discussed in the context of what is clinically significant in calculations of energy expenditure and in light of the limitations of current outcome data.