Author Affiliations: Pennington Biomedical Research Center, Baton Rouge, Louisiana (Drs Bray and Redman) (email@example.com); and Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Orlando (Dr Smith).
In Reply: Dr Westerterp calculates that the individuals in our study eating the low protein diet should have gained more body fat than we reported. He thinks that differences in fecal fat loss between diets is not an adequate explanation, and we agree. He goes on to offer “an underestimation of energy requirement for weight maintenance” as a potential explanation.
To evaluate this suggestion, we first reexamined the differences between our weight-stabilized estimate of energy requirements and baseline energy expenditure, and found that they did not differ significantly between diet groups (low protein diet: −83 kcal/d [95% CI, −411 to 243 kcal/d]; normal protein diet: 177 kcal/d [95% CI, −146 to 503 kcal/d]; and high protein diet: 273 kcal/d [95% CI, −165 to 711 kcal/d]; P = .28), but cumulatively the low protein diet group ingested less total energy than the normal or high protein diet groups (low protein diet: 46 190 kcal [95% CI, 30 742 to 51 364 kcal]; normal protein diet: 54 819 kcal [95% CI, 47 527 to 62 111 kcal]; high protein diet: 50 666 kcal [95% CI, 43 200 to 58 131 kcal]; P = .13).
Bray GA, Redman LM, Smith SR. Dietary Protein and Weight Gain—Reply. JAMA. 2012;307(16):1691-1692. doi:10.1001/jama.2012.533