Background: Taurine has been demonstrated to regulate and improve metabolic health. However, physiological and pathological differences among individuals with overweight or obesity may result in varied responses to taurine supplementation. This study aims to estimate the effects of long-term taurine supplementation on blood lipids, glycemia, and insulin sensitivity in adults with overweight or obesity through a systematic review and meta-analysis. Methods: The literature search was based on six databases (Web of Science, PubMed, Scopus, EMBASE, Cochrane, and SPORTDiscus) up to October 2024. Subgroup analyses were performed based on daily taurine intake dosage (<3 g or 3 g), overweight (BMI 25–29.9 kg/m²), and obesity (BMI ≥30 kg/m²). Results: The final number of studies that met the inclusion criteria was 9 RCTs. The overall analysis showed that taurine supplementation significantly decreased TG (WMD = −0.56 mg/dL, 95% CI: −0.92 to −0.2, p = 0.002, I² = 63%), TC (WMD = −0.71 mg/dL, 95% CI: −1.17 to −0.25, p = 0.002, I² = 73%), and fasting insulin (WMD = −2.15 µU/mL, 95% CI: −3.24 to −1.06, p = 0.0001, I² = 9%). In the subgroup analysis, long-term taurine intake led to BMI improvement in overweight adults (WMD = −1.14 kg/m², 95% CI: −1.81 to −0.47, p = 0.0008, I² = 0%). Meanwhile, improvements in HbA1c (WMD = −0.33%, 95% CI: −0.53 to −0.12, p = 0.002, I² = 16%) and HOMA-IR (WMD = −0.91, 95% CI: −1.74 to −0.08, p = 0.003, I² = 54%) were observed only in obese participants following taurine supplementation. Additionally, the long-term intake of 3 g of taurine significantly improved HbA1c (WMD = −0.37%, 95% CI: −0.61 to −0.13, p = 0.003, I² = 0%) and FPG levels (WMD = −7.14 mg/dL, 95% CI: −12.53 to −1.74, p = 0.003, I² = 70%) in overweight/obesity. Conclusions: Long-term taurine supplementation is particularly effective in improving glycemic control and insulin sensitivity in obesity. Furthermore, higher doses of taurine (3 g per day) demonstrate even greater improvements in glycemic control.

Background: Interval training modalities, including high-intensity interval training (HIIT) and sprint interval training (SIT), are widely recognized for their efficiency and health benefits. However, it remains unclear how baseline fitness levels influence the differential effects of HIIT and SIT on key health-related outcomes. Objective: This meta-analysis aims to compare the effects of HIIT and SIT on cardiorespiratory fitness (CRF) and body fat mass, with subgroup analyses based on participants’ health and training status. Methods: Nine randomized controlled trials (n = 666) were included. Primary outcomes were changes in VO ₂ max/VO ₂ peak and body fat percentage. Data were synthesized using standard mean difference (SMD) or weighted mean difference (WMD), with subgroup analyses stratified by population type (healthy/trained vs. overweight/obese). This review was registered in PROSPERO (CRD420251016362; registered on 15 March 2025). Results: Both HIIT and SIT significantly improved CRF (SMD = 1.54; 95% CI: 0.89–2.18; p < 0.00001) and reduced body fat mass (WMD = −3.45%; 95% CI: −5.04 to −1.87; p < 0.0001) compared to control. Subgroup analyses revealed that HIIT was more effective in improving CRF in overweight/obese individuals (SMD = −0.97; p = 0.0004), while SIT was more effective in reducing fat mass among healthy or trained populations (WMD = 5.85; p < 0.00001). Conclusion: Both HIIT and SIT are effective interventions for enhancing CRF and reducing body fat, but their relative efficacy may depend on participants’ baseline health status. HIIT appears optimal for individuals with lower fitness levels, while SIT may be preferable for time-efficient fat reduction in trained populations. Tailoring interval training prescriptions to individual characteristics is recommended. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251016362 .

Background: Obesity is associated with metabolic dysregulation, mood disturbance, and poor sleep quality. Although dietary fiber and probiotic supplementation have both been proposed as microbiome-targeted strategies for obesity management, their independent and combined effects remain unclear. Methods: In this double-blind, randomized, placebo-controlled 2 × 2 factorial trial, 56 adults with obesity were randomized to placebo, dietary fiber, probiotic, or combined supplementation for 8 weeks. One withdrew during baseline assessment, and 55 participants were included in the intention-to-treat analysis. Outcomes included metabolic syndrome-related indicators, mood assessed by the Profile of Mood State, and sleep quality assessed by the Pittsburgh Sleep Quality Index. Intervention effects were evaluated using factorial ANCOVA with baseline adjustment. Results: No significant dietary fiber × probiotic interactions were detected. Dietary fiber supplementation showed selective favorable effects, mainly on HDL cholesterol and mood-related outcomes. Probiotic supplementation showed a significant main effect primarily on HDL cholesterol but did not remain significant after FDR correction. Sleep-related improvements were observed only in within-group analyses and were not supported by significant factorial ANCOVA effects. Combined supplementation did not provide additional benefits over single-component interventions. Conclusions: Dietary fiber supplementation may have selective favorable effects in adults with obesity, particularly on HDL cholesterol and mood-related outcomes. The absence of additional benefit from combined supplementation suggests that the effectiveness of synbiotic strategies may depend on the compatibility between the selected dietary fiber and probiotic strains.