Exercise, Nutrition, and Neuromuscular Electrical Stimulation for Sarcopenic Obesity: A Systematic Review and Meta-Analysis of Management in Middle-Aged and Older Adults

Background/Objective: Sarcopenic obesity (SO), a pathological syndrome characterized by the co-existence of diminished muscle mass and excessive adipose accumulation, significantly compromises the quality of life in older adults. The purpose of this study was to systematically evaluate the efficacy of exercise, nutritional interventions, and neuromuscular electrical stimulation (NMES) in preventing and managing SO in middle-aged and older adults. Methods: A comprehensive search was conducted across PubMed, Web of Science, Embase, Cochrane Library, and CNKI for randomized controlled trials (RCTs) until January 2025. Meta-analyses were performed using the random-effects model and fixed-effects model based on the degree of heterogeneity and calculating the mean differences (MD) with 95% confidence intervals (CI). Subgroup analyses compared the intervention types. Results: Twenty-nine RCTs (1622 participants) were included. Exercise interventions significantly reduced the body fat percentage (MD = −2.79%, 95% CI: −3.94, −1.64, p < 0.001, I² = 74%), fat mass (MD = −6.77 kg, 95% CI: −11.48, −2.06, p = 0.005, I² = 98%), waist circumference (MD = −2.05 cm, 95% CI: −3.64, −0.46, p = 0.01, I² = 0%) and LDL-C (MD: −7.45 mg/dL, 95% CI: −13.82, −1.07, p = 0.02, I² = 0%), while improving handgrip strength (MD = 2.35 kg, 95% CI: 1.99, 2.70, p < 0.001, I² = 52%) and gait speed (MD = 0.19 m/s, 95% CI: 0.13, 0.24, p < 0.001, I² = 89%). Mixed training outperformed resistance-only regimens in reducing the body fat percentage and enhancing functional outcomes. NMES reduced the body fat percentage (MD = −2.01%, 95% CI: −3.54, −0.48, p = 0.01, I² = 93%) and waist circumference (MD = −1.72 cm, 95% CI: −2.35, −1.09, p < 0.001, I² = 0%) while increasing the Skeletal Muscle Index (MD = 0.26 kg/m², 95% CI: 0.22, 0.29, p < 0.001, I² = 38%). Synergy with nutritional supplementation amplified these effects. Nutritional interventions modestly improved total fat-free mass (MD = 0.77 kg, 95% CI: 0.04, 1.50, p = 0.04, I² = 0%) and handgrip strength (MD = 1.35 kg, 95% CI: 0.71, 2.00, p < 0.001, I² = 0%) but showed no significant impact on the metabolic markers (TG, TC, glucose, hemoglobin, and HOMA-IR). Conclusions: Exercise, particularly multimodal regimens combining aerobic and resistance training, is the cornerstone for improving body composition and physical function in SO. NMES serves as an effective adjunct for accelerating fat loss, while nutritional strategies require integration with exercise or prolonged implementation to yield clinically meaningful outcomes. Future research should prioritize standardized diagnostic criteria and long-term efficacy assessments of multimodal interventions.