PP114 - EFFECTS OF A MORE PLANT-BASED VS ANIMAL-BASED DIET ON PROTEIN INTAKE AND MUSCLE MASS IN OLDER ADULTS DURING RESISTANCE EXERCISE TRAINING: THE IMPACT RANDOMIZED CONTROLLED TRIAL
PP114
EFFECTS OF A MORE PLANT-BASED VS ANIMAL-BASED DIET ON PROTEIN INTAKE AND MUSCLE MASS IN OLDER ADULTS DURING RESISTANCE EXERCISE TRAINING: THE IMPACT RANDOMIZED CONTROLLED TRIAL
S. L. van Oppenraaij1,2,*, P. J. Weijs1,2,3, S. Verlaan1
1Nutrition and Dietetics, Amsterdam University of Applied Sciences, 2Amsterdam Public Health, Aging and Later Life, Vrije Universiteit Amsterdam, 3Nutrition and Dietetics, Amsterdam University Medical Center, Amsterdam, Netherlands
Rationale: A predominantly plant-based diet may reduce the risk of non-communicable diseases and benefit the climate, but may also result in lower protein intake. This study investigated the effects of a vegetarian vs omnivorous diet, both combined with resistance exercise training, on protein intake and appendicular muscle mass in adults aged 55+.
Methods: In this non-inferiority trial, 108 adults (66 [62-69] y; 58% female) were randomized to a self-selected, high-protein vegetarian or omnivorous diet combined with a 12-week resistance exercise program (3 sessions/week). Primary outcomes were protein intake (3-day food records) and appendicular muscle mass (DXA), with non-inferiority margins of 0.12 g/kg/d and 0.25 kg, respectively. Secondary outcomes included leg press strength, chair stand test, and handgrip strength.
Results: Non-inferiority was not shown for protein intake (Δ-0.32 g/kg/d; 95% CI -0.46, -0.18) or appendicular muscle mass (Δ-0.27 kg; 95% CI -0.64, 0.10), with protein intake being lower in the vegetarian group. Both groups achieved protein intakes of ≥1.2 g/kg/d and their targeted protein-source composition: 1.24 [1.14, 1.35] g/kg/d in the vegetarian group (77% plant-based protein) and 1.58 [1.48, 1.69] g/kg/d in the omnivorous group (68% animal-based protein). Appendicular muscle mass significantly increased in both the vegetarian (+0.39 [0.13, 0.65] kg, p = 0.004) and the omnivorous group (+0.66 [0.40, 0.93] kg, p <0.001). Leg press strength and chair stand test significantly improved in both groups, with no between-group differences.
Conclusion: Although protein intake was lower in the vegetarian group, both groups achieved a protein intake of ≥1.2 g/kg/d. While gains in appendicular muscle mass were not equal, both groups improved in muscle mass, strength, and function.
Disclosure of Interest: None declared