BACKGROUND: A low resting metabolic rate (RMR) for a given body size and composition is partly genetically determined and has been suggested to be a risk factor for weight gain. Moreover, a low relative RMR has been reported in some, but not all, studies of formerly obese persons. The inconsistent reports may be due to a lack of statistical power to detect small differences in RMR and improper adjustment for body size and composition. OBJECTIVE: We conducted a meta-analysis based on published studies of RMR in formerly obese persons [body mass index (in kg/m2) < or = 27] and matched control subjects who had never been obese. DESIGN: We performed both an individual subject data meta-analysis and a traditional meta-analysis. RESULTS: The individual subject data meta-analysis included 124 formerly obese and 121 control subjects. RMR adjusted for differences in fat-free mass and fat mass was 2.9% lower in formerly obese subjects than in control subjects (P = 0.09). A low relative RMR (> 1 SD below the mean of the control group) was found in 3.3% of the control subjects and in 15.3% of the formerly obese subjects [difference: 12% (95% CI: 4.7%, 19.3%); P < 0.003]. The traditional meta-analysis was based on 12 studies (including 94 formerly obese and 99 control subjects) and included 3 studies not represented in the individual subject data analysis. In this analysis, relative RMR was lower in the formerly obese group than in the control group by 5.1% (95% CI: 1.7%, 8.6%). CONCLUSIONS: Formerly obese subjects had a 3-5% lower mean relative RMR than control subjects; the difference could be explained by a low RMR being more frequent among the formerly obese subjects than among the control subjects. Whether the cause of the low RMR is genetic or acquired, the existence of a low RMR is likely to contribute to the high rate of weight regain in formerly obese persons.
BACKGROUND: A low resting metabolic rate (RMR) for a given body size and composition is partly genetically determined and has been suggested to be a risk factor for weight gain. Moreover, a low relative RMR has been reported in some, but not all, studies of formerly obesepersons. The inconsistent reports may be due to a lack of statistical power to detect small differences in RMR and improper adjustment for body size and composition. OBJECTIVE: We conducted a meta-analysis based on published studies of RMR in formerly obesepersons [body mass index (in kg/m2) < or = 27] and matched control subjects who had never been obese. DESIGN: We performed both an individual subject data meta-analysis and a traditional meta-analysis. RESULTS: The individual subject data meta-analysis included 124 formerly obese and 121 control subjects. RMR adjusted for differences in fat-free mass and fat mass was 2.9% lower in formerly obese subjects than in control subjects (P = 0.09). A low relative RMR (> 1 SD below the mean of the control group) was found in 3.3% of the control subjects and in 15.3% of the formerly obese subjects [difference: 12% (95% CI: 4.7%, 19.3%); P < 0.003]. The traditional meta-analysis was based on 12 studies (including 94 formerly obese and 99 control subjects) and included 3 studies not represented in the individual subject data analysis. In this analysis, relative RMR was lower in the formerly obese group than in the control group by 5.1% (95% CI: 1.7%, 8.6%). CONCLUSIONS: Formerly obese subjects had a 3-5% lower mean relative RMR than control subjects; the difference could be explained by a low RMR being more frequent among the formerly obese subjects than among the control subjects. Whether the cause of the low RMR is genetic or acquired, the existence of a low RMR is likely to contribute to the high rate of weight regain in formerly obesepersons.
Authors: James Rochon; Connie W Bales; Eric Ravussin; Leanne M Redman; John O Holloszy; Susan B Racette; Susan B Roberts; Sai Krupa Das; Sergei Romashkan; Katherine M Galan; Evan C Hadley; William E Kraus Journal: J Gerontol A Biol Sci Med Sci Date: 2010-10-05 Impact factor: 6.053
Authors: R P Shook; G A Hand; A E Paluch; X Wang; R Moran; J R Hébert; J M Jakicic; S N Blair Journal: Eur J Clin Nutr Date: 2015-11-25 Impact factor: 4.016
Authors: Kristen M Beavers; Mary F Lyles; Cralen C Davis; Xuewen Wang; Daniel P Beavers; Barbara J Nicklas Journal: Am J Clin Nutr Date: 2011-07-27 Impact factor: 7.045
Authors: Paul S Maclean; Audrey Bergouignan; Marc-Andre Cornier; Matthew R Jackman Journal: Am J Physiol Regul Integr Comp Physiol Date: 2011-06-15 Impact factor: 3.619
Authors: Victoria A Catenacci; Zhaoxing Pan; Danielle Ostendorf; Sarah Brannon; Wendolyn S Gozansky; Mark P Mattson; Bronwen Martin; Paul S MacLean; Edward L Melanson; William Troy Donahoo Journal: Obesity (Silver Spring) Date: 2016-09 Impact factor: 5.002