Obesity negatively impacts lower extremity physical function (LEPF) in older adults. Exercise and a higher protein diet are both known to positively and independently impact body composition, muscle strength and LEPF during weight loss; however, their potential interactive effects have not been well characterized in older women. PURPOSE: The aim of this study was to determine the relative efficacy of a higher protein diet with or without exercise to improve body composition, muscle strength, and LEPF in older inactive overweight/obese women after weight loss. METHODS: Postmenopausal women (BMI 31.1 +/- 5.1 kg/m2, 69.2 +/- 3.6 y) completed a 6-month weight loss program after randomization to three groups (n = 72 randomized; 15% drop-out): (1) higher protein diet (PRO, approximately 30% energy from protein; n = 20), (2) PRO plus exercise (PRO+EX; n = 19), or (3) a conventional protein control diet plus EX (CON+EX, approximately 18% energy from protein; n = 22). EX was supervised, multicomponent (aerobic, muscle strengthening, balance, flexibility) and 3 sessions/week. Body composition was measured via dual-energy x-ray absorptiometry; leg strength by isokinetic dynamometry; and LEPF via 6-minute walk, 8-foot up and go, and 30-second chair stand tests. RESULTS: Changes in weight (-7.5 +/- 4.1 kg; -9.2 +/- 4.8%), fat mass, and leg lean mass did not differ among groups (all p > 0.50). Despite weight loss, muscle strength improved in the exercise groups (PRO+EX and CON+EX) whereas it declined in the PRO group (p = 0.008). For all LEPF measures, the PRO group had attenuated improvements compared to both PRO+EX and CON+EX (all p < 0.01). CONCLUSION: Exercise during weight loss is critical to preserve strength and enhance LEPF; however, a higher protein diet does not appear to influence body composition, muscle strength or LEPF changes when combined with multicomponent exercise.

Full text (sometimes free) may be available at these link(s):      help

• DOI
• PubMed
• PDF locator
• publisher