Additive effect of Tai Chi during dietary weight loss on body composition in obese postmenopausal women

Background. Tai Chi has not been extensively studied as a weight loss modality that will improve body composition in older women. The purpose of the investigation was to examine the additive effect of Tai Chi during dietary weight loss on body composition in obese, postmenopausal women. Methods. A 16-week trial was conducted with 27 obese women randomized to a weight loss only group (WL, n=13, age 62.7 ± 6.0 years, BMI = 34.8 ± 2.9 kg/m2) or a Tai Chi plus weight loss group (TCWL, n=14, age 60.4 ± 5.9 years, BMI = 34.3 ± 5.1 kg/m2). Both groups received a Dietary Approaches to Stop Hypertension-based weight loss program. The TCWL group also participated in three Tai Chi exercise sessions (∼45 min) per week. Outcome measures included total body mass, fat mass, fat-free mass, mid-thigh tissue composition, and waist circumference. Results. Both groups significantly lost body mass (TCWL, −2.2 ± 0.9 kg; WL, −3.7 ± 0.9 kg; both p \u3c 0.05) with no between-group differences. The TCWL group had a borderline attenuation in fat-free mass change compared to the WL group (−0.2 kg vs. −1.2 kg, p = 0.056). There were significant between-group differences in mid-thigh normal density muscle (−5.4 ± 2.4 cm2 vs. −13.2 ± 2.4 cm2, p = 0.031). There were no significant between-group changes in any other measures. Conclusion. Tai Chi appears to prevent the loss of mid-thigh normal density muscle and aid in the preservation of fat-free mass but does not have significant additive effect on body fat measures during dietary weight loss in older, postmenopausal women