To the Editor In a recent JAMA Patient Page, Dr Guth1 stated that “A total of 3500 calories equals 1 pound of body weight.” However, the energy content of body weight varies widely by race, sex, and age. The calorie density value of 3500 is based on the composition of adipose tissue. However, humans are rarely more than half adipose tissue; most of the remainder is skeletal muscle and bone, which have much lower calorie densities.
Allison DB, Thomas DM, Heymsfield SB. Energy Intake and Weight Loss. JAMA. 2014;312(24):2687-2688. doi:10.1001/jama.2014.15513