Racial Differences in Relative Skeletal Muscle Mass Loss During Diet-Induced Weight Loss in Women

Academic Article

Abstract

  • © 2018 The Obesity Society Objective: It is unclear whether there are race-specific differences in the maintenance of skeletal muscle during energy restriction. Changes in relative skeletal muscle index (RSMI; limb lean tissue divided by height squared) were compared following (1) diet alone, (2) diet + aerobic training, or (3) diet + resistance training. Methods: Overweight, sedentary African American (AA; n = 72) and European American (EA; n = 68) women were provided an 800-kcal/d diet to reduce BMI < 25 kg/m2. Regional fat-free mass was measured with dual-energy x-ray absorptiometry. Steady-state VO2 and heart rate responses during walking were measured. Results: AA women had greater RSMI and preserved RSMI during diet alone, while RSMI was significantly reduced among EA women (EA women –3.6% vs. AA women + 1.1%; P < 0.05). Diet + resistance training subjects retained RSMI (EA women + 0.2% vs. AA women + 1.4%; P = 50.05), whereas diet + aerobic training subjects decreased RSMI (EA women –1.4% vs. AA women –1.5%; P < 0.05). Maintenance of RSMI was related to delta walking ease and economy. Conclusions: Compared with AA women, EA women are less muscular and lose more muscle during weight loss without resistance training. During diet-induced weight loss, resistance training preserves skeletal muscle, especially among premenopausal EA women. Maintenance of muscle during weight loss associates with better ease and economy of walking.
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Hunter GR; Bryan DR; Borges JH; David Diggs M; Carter SJ
  • Start Page

  • 1255
  • End Page

  • 1260
  • Volume

  • 26
  • Issue

  • 8