This paper aimed to systematically evaluate the effects of hypoxic training at different fraction of inspired oxygen (FiO?) on body composition, glucose metabolism, and lipid metabolism in obese individuals, and to determine the optimal oxygen concentration range to provide scientific evidence for personalized and precise hypoxic exercise prescriptions. A systematic search was conducted in the Cochrane Library, PubMed, Web of Science, Embase, and CNKI databases for randomized controlled trials and pre-post intervention studies published up to February 31, 2025, involving hypoxic training interventions in obese populations. Meta-analysis was performed using RevMan 5.4 software to assess the effects of different fraction of inspired oxygen (FiO₂≤14% vs. FiO₂>14%) on BMI, body fat percentage, waist circumference, fasting blood glucose, insulin, HOMA-IR, triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C), with subgroup analyses based on oxygen concentration. A total of 22 studies involving 292 participants were included. Meta-analysis showed that hypoxic training significantly reduced BMI (mean difference (MD)=–2.29,95%CI: –3.42 to –1.17, P< 0.000 1), body fat percentage (MD=–2.32,95%CI: –3.16 to –1.47,P<0.001), waist circumference (MD=–3.79 , 95%CI: –6.73 to –0.85, P=0.01), fasting blood glucose (MD=–3.58,95%CI: –6.23 to –0.93, P=0.008), insulin (MD=–1.60, 95%CI: –2.98 to –0.22, P=0.02), TG (MD=–0.18, 95%CI: –0.25 to –0.12, P<0.001), and LDL-C (MD=–0.25, 95%CI: –0.39 to –0.11, P=0.000 3). Greater improvements were observed under moderate hypoxic conditions with FiO₂>14%. Changes in HOMA-IR (MD=–0.74, 95%CI: –1.52 to 0.04, P=0.06) and HDL-C (MD=–0.09, 95%CI: –0.21 to 0.02, P=0.11) were not statistically significant. Hypoxic training can significantly improve body composition, glucose metabolism, and lipid metabolism indicators in obese individuals, with greater benefits observed under moderate hypoxia (FiO >14%). As a key parameter in hypoxic exercise interventions, the precise setting of oxygen concentration is crucial for optimizing intervention outcomes.