Reply to D Chapelot and J Louis-Sylvestre

Division of Endocrinology, Metabolism and Diabetes Department of Medicine University of Colorado Health Sciences Center 4200 East Ninth Avenue, B151 Denver, CO 80262 E-mail: robert.eckel{at}uchsc.edu

Dear Sir:

My colleagues and I appreciate the comments of Chapelot and Louis-Sylvestre in response to our article "Occasional physical inactivity combined with a high-fat diet may be important in the development and maintenance of obesity in human subjects" (1). In this article, we discussed our finding that a high-fat diet can influence fat balance produced by a day of physical inactivity more than can a high-carbohydrate diet.

In general, we agree with the issues raised by Chapelot and Louis-Sylvestre. However, although energy intake was fixed in our experiment, we believe that well-controlled metabolic studies may predict patterns that occur in the free-living environment. Moreover, the manner in which the experimental diet was used may represent the ad libitum patterns of many adults, at least in the United States. This study was actually designed to look at predictors of weight gain over 4 y. The data collection is now complete, and we are in the process of analyzing the results to see whether the nutrient predictors of change in fat mass are similar or different from those published in the Journal in 2001.

REFERENCE

1. Shepard TY, Weil KM, Sharp TA, et al. Occasional physical inactivity combined with a high-fat diet may be important in the development and maintenance of obesity in human subjects. Am J Clin Nutr 2001;73:703–8.