Original Communication The energy expenditure of postmenopausal women classified as restrained or unrestrained eaters

Objective: Restrained eating is a common dietary practice among individuals who are attempting to prevent weight gain, but little is known about differences in energy physiology and regulation between restrained and unrestrainedeaters. We investigatedthis issue in non-obese free-living postmenopausal women classifiedas longterm restrained( n ¼ 26) or unrestrained( n ¼ 34) eaters group matched for body mass index (BMI). Measurements: Measurements were made of total energy expenditure (TEE), resting energy expenditure (REE), body composition, reported leisure time activity, maximal aerobic capacity (VO2max) andweight change d uring the study period. In addition, physical activity level (PAL) and nonexercise activity thermogenesis (NEAT) were calculatedfrom measuredvariables. Results: There were no significant differences between the groups in body composition, weight change, aerobic capacity or total leisure time activity. Relationships between fat-free mass (FFM) andboth REE andTEE, andthe relationship between work loadandenergy expenditure in the test of maximal oxygen consumption, were also not different between groups. However, restrained eaters had a significantly lower PAL (equal to TEE=REE, 1.72 � 0.04 vs 1.84� 0.04, P < 0.05). In addition, in multiple regression models predicting NEAT, NEAT was significantly lower in restrainedeaters than unrestrainedeaters andthere was a positive relationship between NEAT andweight change in unrestrainedeaters but no relationship in restrainedeaters ( P < 0.05). Conclusions: In contrast to a previous report, we foundno significant d ifference in TEE between restrainedand unrestrained eaters. PAL was slightly lower in restrained eaters, apparently due to reduced NEAT, and restrained eaters also lackedthe positive association between NEAT andbod y weight change seen in unrestrainedeaters. This latter finding, if confirmed in future studies, could help explain an increased susceptibility of restrained eaters to weight gain. Sponsorship: NIH grants AG12829, DK46124 andT32AG00209, andUS Cooperative Agreement number 58