Limited reports have highlighted the protective role of Healthy Nordic Food Index (HNFI) score against several chronic diseases like cancers and cardiovascular disorders. However, its beneficial role in obesity-related cardiometabolic risk factors is not well understood. In the current work, we examined the adherence to Nordic diet by estimating HNFI score and its association with metabolic syndrome and its components among Iranian population. In the current cross-sectional study, 339 individuals with obesity aged 20-50 years were recruited. Dietary intake was assessed by a validated food frequency questionnaire (FFQ). Enzymatic methods were used to assess serum lipids and glycemic markers. Blood pressure was measured by sphygmomanometer and body composition with bioelectrical impedance analysis (BIA). No significant differences were found in age, sex distribution, waist circumference, body mass index categories, socioeconomic status score, fat mass percentage, fat-free mass, basal metabolic rate across quartiles or physical activity of HNFI (all P > 0.05). Also, higher energy, saturated fatty acids, sugar, fiber, β-carotene, yogurt, milk, and potatoes was shown in higher HNFI categories (P < 0.05). Higher adherence to Nordic diet was accompanied with lower systolic blood pressure (SBP, P < 0.001), total cholesterol (P,0.047) and low-density lipoprotein cholesterol (LDL-C) concentrations (P, 0.034) after adjusting for age, body mass index (BMI), physical activity level). In multinomial logistic regression analysis, HNFI showed no significant association with most obesity-related cardiometabolic risk factors. After adjustment for age and sex, participants in the third HNFI quartile had lower SBP, DBP, TC compared to participants in first HNFI quartile (P < 0.05). No significant associations were observed for FBS, TG, insulin, HOMA-IR, α-MSH, and AgRP (OR > 0.05). According to our results, higher adherence to Nordic diet was associated with favorable cardio-metabolic risk factors among apparently healthy adults with obesity. Further researches are warranted to better clarify these findings.

We aimed to investigate the association of chrono-nutrition components with anthropometric measures and body composition in adults living in Tehran. This cross-sectional study was conducted on 450 healthy adults. The exposures of the study were meal frequency, meal timing, meal irregularity, breakfast skipping, night fasting duration, time of the first and last eating occasion (EO), and the time interval from the last meal to bed. The outcomes were body mass index (BMI), waist circumference (WC), neck circumference (NC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), body adiposity index (BAI), body roundness index (BRI), A body shape index (ABSI), percentage of body fat (PBF), fat mass (FM), fat-free mass (FFM), and muscle mass (MM). Bonferroni correction was applied and the significance level was less than 0.004. Using ANCOVA, after adjusting for confounders, late lunch eating was associated with a lower PBF. There was a positive trend across the tertiles of dinner time with greater WHtR (mean difference=0.019; Ptrend=0.025) and BRI (mean difference=0.24; Ptrend=0.022). Moreover, increased irregularity at dinner time was associated with higher levels of PBF (Ptrend=0.026) and FM (Ptrend=0.025). Also, longer overnight fasting was associated with lower NC (Ptrend=0.049) and a greater BRI (Ptrend=0.050). We found differences across the time interval from the last meal to bed with greater means of BAI (Ptrend=0.026), PBF (Ptrend=0.014), and FM (Ptrend=0.020). However, after applying the Bonferroni correction, we found no significant association between chrono-nutrition components and anthropometric measures and body composition in adults living in Tehran. Further studies are necessary to confirm the results.

Infertility problems affect 15% of the world's population, with male factors accounting for up to 30% of cases. The relationship between male infertility and nutritional status remains inconclusive, as most studies rely on BMI without considering other parameters in their evaluation. Therefore, this study aimed to comprehensively assess male body composition and its impact on semen parameters. The aim of our study was to evaluate the relationship between seminal quality (seminogram) and nutritional status (body mass index, waist-hip index and percentage of muscle, fat and visceral mass). 117 men from infertile couples were recruited from December 2021 to October 2023 who attended the Gynecology-Esterility consultation at the Hospital of Denia (Spain). Anthropometric variables were collected by physical examination and clinical variables by semen analysis. Statistical analysis was performed using the Mann-Whitney U test and linear regression models. Our work showed a direct and significant linear relationship (p=0.027) between hip circumference and seminal volume. No association was found between the rest of anthropometric parameters and seminal quality. The results of this study suggest that there is a statistically significant positive association between seminal volume and hip circumference, but we found no association between the rest of anthropometric parameters and seminal quality.

Effects of caloric restriction with different doses of exercise on fat loss in people living with type 2 diabetes: A secondary analysis of the DOSE-EX randomized clinical trial

Association of muscle mass, muscle quality, and function with mortality in community-dwelling older adults: Focus on segmental phase angle and extracellular to intracellular water ratio.

Association between early-life exposure to mercury and cardiometabolic risk factors development in adolescence.

Phase angle as a prognostic factor of survival in patients with metastatic prostate cancer.

Aim. To clarify the role of acyl-ghrelin in the development of protein-energy wasting of haemodialysis patients (HD). Materials and methods. A total of 645 patients receiving treatment with programmatic bicarbonate HD for 8.4 ± 5.3 years, including 345 women and 300 men, the average age was 56.8 ± 12.8 years. Nutritional status was assessed using the method proposed by the International Society of Renal Nutrition and Metabolism (ISRNM). For the quantitative determination of acyl-ghrelin, the enzyme-linked immunosorbent assay kit “Active Ghrelin ELISA Kit” (highly sensitive method) from Sceti KK, Japan was used in this work. Reference values: 30–62 fmol/ml. Results. The prevalence of protein-energy wasting (PEW) using the ISRNM method was 24.9% (160 patients). Reduced levels of acyl-ghrelin were detected in 352 (54.5%) patients. The average acyl-ghrelin values in patients without signs of PEW were 50.2 ± 10.3 fmol/ml, and in patients with PEW 24.9 ± 9.2 fmol/ml (p 0.0001). Patients with reduced acyl-ghrelin levels had statistically significantly lower values of total protein, albumin, prealbumin, total cholesterol, and transferrin than patients with normal acyl-ghrelin levels (p 0.0001, p 0.0001, p 0.0001, p 0.001 and p 0.0001, respectively). Also, patients with reduced acyl-ghrelin levels were characterized by statistically significantly lower values of BMI, skeletal muscle mass, and percentage of body fat mass (p 0.001, p 0.001, p 0.001, respectively). Conclusion. The prevalence of PEW in HD patients according to the ISRNM method was 24.9%. A reduced level of acyl-ghrelin in the blood serum may be an important pathogenetic link in the development of PEW in HD patients.

Introduction: Obesity is a well-known risk factor for type 2 diabetes and cardiovascular diseases. However, the prevalence of these disorders varies greatly due to highly heterogeneous metabolic clinical situations. A subtype of obesity, termed "metabolically healthy obesity" (MHO), includes obese individuals with a significantly lower risk of cardiometabolic complications. This phenotype can be assessed by various definitions, which still lack consensus. Objective: Our study aimed to identify metabolically healthy obese (MHO) subjects among obese adults consulting at the department of Clinical Physiology and Functional Explorations, Metabolic and Nutrition Unit (CHU Annaba, Algeria), and to determine their percentage of body fat mass. Materials and Methods: The present study is a retrospective cross-sectional study. Inclusion Criteria were adults Aged 18–65 years, BMI ≥ 30 kg/m², and metabolic syndrome parameters. The criteria used to define the phenotype MHO were Lavie and al.'s recent harmonization proposal: BMI ≥ 30 kg/m² and none of the components of metabolic syndrome. 61 patients were selected according to the inclusion criteria. Conclusion: This study showed that a non-negligible frequency of obese patients consulting at our department were metabolically healthy according to strict definition criteria. Special attention should be given to these patients to help them maintain their metabolic health and prevent conversion to an unhealthy metabolic profile.

Gestational hypertension (GH) (new-onset pregnancy hypertension without multisystem preeclampsia features) is associated with an increased risk of long-term cardiometabolic disease. However, early postpartum metabolic trends contributing to these adverse outcomes have been under-investigated. This sub-study aimed to characterise body composition and cardiometabolic parameters in the early years after GH. This longitudinal sub-study of the Postpartum Physiology, Psychology and Paediatric cohort study assessed women 6 months (n = 23) and 2 years (n = 14) after GH versus normotensive pregnancy (n = 118). Anthropometry, body composition via bioelectrical impedance analysis, serum biochemistry and metabolic syndrome rates were assessed. Six months after GH, women had lower rates of breastfeeding and markedly higher systolic and diastolic blood pressures, weight (81.4 kg vs. 63.5 kg, p < 0.001), obesity rates (52% vs. 18%, p < 0.001) and percent fat mass (43.2 ± 7.1% vs. 35.7 ± 9.4%, p < 0.001) compared to controls. These women also had lower high-density lipoprotein cholesterol levels and higher triglyceride, insulin and homeostatic model assessment of insulin resistance levels (1.94 [1.22-3.80] vs. 0.97 [0.62-1.43], p < 0.001). These metabolic differences persisted at 2 years postpartum, in addition to higher low-density lipoprotein cholesterol levels (2.7 [2.4-3.2] mmol/L vs. 2.3 [1.9-2.8] mmol/L, p = 0.04, q = 0.07). Metabolic syndrome rates were also higher (36% vs. 4%, p = 0.001). Percent fat mass, waist-to-hip ratio and total cholesterol improved for all women over time. Evidence of cardiometabolic dysfunction, including obesity, percent fat mass, dyslipidaemia and markers of insulin resistance, was present at 6 months after GH. By 2 years postpartum, over one-third of these women meet metabolic syndrome criteria. Further studies are required to characterise targets for early postpartum intervention to mitigate future cardiometabolic health outcomes.

Osteoarthritis is a prevalent joint disorder with a significant global burden. Identifying individuals at risk for osteoarthritis is essential, and obesity indices may be the key to early detection. This study aimed to explore the relationships between anthropometric indices of obesity and osteoarthritis and to assess their predictive abilities. This cross-sectional study included 54,041 participants aged 20years or older from NHANES cycles spanning 1999 to 2023. Anthropometric indices of obesity included body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), weight-adjusted waist index (WWI), body roundness index (BRI), body fat percentage (BFP), relative fat mass (RFM), and conicity index (CI). Multivariate logistic regression and receiver operating characteristic curves were conducted to evaluate the associations and predictive capacities of these indices for osteoarthritis. BMI, WC, WHtR, WWI, BRI, BFP, RFM, and CI were independently positively associated with osteoarthritis risk. RFM (OR = 1.662, 95% CI 1.571 ~ 1.757, P < 0.001) and BFP (OR = 1.555, 95% CI 1.494 ~ 1.617, P < 0.001) showed the strongest associations. The AUCs for the indices ranged from 0.581 to 0.706. BFP had the largest AUC (0.706, 95% CI 0.700 ~ 0.712), with an optimal cut-off of 35.922 (sensitivity, 71.292%; specificity, 59.258%), followed by WWI (AUC = 0.660, 95% CI 0.653 ~ 0.667), CI (AUC = 0.647, 95% CI 0.640 ~ 0.654), and RFM (AUC = 0.639, 95% CI 0.632 ~ 0.646). BFP and RFM emerged as valuable tools for early osteoarthritis identification. Key Points • Anthropometric indices of obesity are positively associated with osteoarthritis and can serve as predictors of its risk. • Relative fat mass (RFM) demonstrates the strongest association with osteoarthritis risk. • Body fat percentage (BFP) exhibits the strongest predictive ability for osteoarthritis. • BFP and RFM are recommended for early osteoarthritis identification.

Background/Objectives: There are generally no mandates for law enforcement officers to maintain career fitness. Evidence documenting the motivation of officers who are physically active could support training and health and wellness initiatives, while preventing disease (e.g., cardiovascular, metabolic) in this population. This cross-sectional study derived relationships between motivation, physical activity (PA), resistance training (RT) participation, and health and fitness in officers. Methods: Sixty officers completed a questionnaire assessing PA (weekly strenuous, moderate, mild exercise sessions; activity score) and RT (RT frequency [RTF]; weekly sessions over 3 months [RT3M]; sessions in past 7 days [RT7D]). Motivation (amotivation, external, introjected, identified, integrated, and intrinsic regulation) was measured via the Behavioral Regulation in Exercise Questionnaire. Health and fitness tests included resting heart rate (RHR), blood pressure, skeletal muscle mass (SMM%) and fat mass (FM%) percentage, waist-to-hip ratio, sit-and-reach, grip strength, push-ups, sit-ups, and step test. Spearman’s correlations (p < 0.05) derived relationships between motivation and all other variables. Results: All intrinsic motivation styles correlated with strenuous exercise sessions, RTF, RT3M, and push-ups (ρ = 0.286–0.670). Identified, integrated, and intrinsic regulation correlated with activity score and sit-ups (ρ = 0.287–0.472). Identified (ρ = 0.444) and integrated (ρ = 0.341) regulation related to RT7D. Amotivation related to RTF (ρ = −0.295) and RT3M (ρ = −0.290). External, introjected, and identified regulation correlated with RHR (ρ = ±0.270–0.338). Integrated and intrinsic regulation positively related to SMM% and negatively related to FM% (ρ = ±0.265–0.323). Conclusions: Internally motivated officers completed strenuous exercise and RT, and had better RHR, body composition, and muscular endurance. Training staff should develop intrinsic motivation styles in personnel to enhance their well-being.

To determine the energetic and hormonal predictors of advanced menstrual recovery (≥2 consecutive menstrual cycles of <36 days) in the REFUEL study, a 12-month intervention of increased energy intake in exercising women with Oligo/Amenorrhea. Participants (21.8±0.7 years; n=25) were categorized based on whether they experienced advanced menstrual recovery (REC) or not (non-REC). Potential recovery predictors were measured at baseline (BL) and at the time point preceding advanced menstrual recovery (PRE). For the non-REC group, PRE was the measurement preceding the last two menstrual cycles/28-day amenorrheic monitoring periods recorded during the intervention. Predictors included body composition, energy intake, energy availability, urinary estrone-1-glucuronide (E1G) and pregnanediol glucuronide (PdG), serum metabolic hormones, and resting metabolic rate variables. T-tests and Mann-Whitney U tests assessed group differences. Logistic regressions determined recovery predictors. The REC group had higher BL percent fat (25.7±1.0 vs. 21.8±1.0 %, p=0.006) and fat mass (14.7±0.7 vs. 11.6±0.7 kg, p=0.003), and fat mass (15.3±0.6 vs. 13.4±0.5 kg, p=0.019), IGF-1 (273.1±13.5 vs. 229.6±19.3 ng/mL, p=0.036), and leptin (7.5±1.3 vs. 4.6±0.7 ng/mL, p=0.033) at PRE than the non-REC group. E1G and PdG increased in the REC group (from 27.6±4.5 to 35.3±5.0 ng/mL, p=0.007; from 1.2±0.2 to 1.3±0.2 µg/mL, p<0.001). Predictors of menstrual recovery were the number of menstrual cycles experienced in the 12 months prior to the intervention, BL percent fat and fat mass, and fat mass and IGF-1 at PRE (p<0.05). Combining BL fat mass and previous 12-month menstrual frequency correctly classified 91.3% of women as REC or non-REC. A higher fat mass and previous pattern (12-month) of frequency of menses may have an important role for advanced menstrual recovery to be achieved.

Abstract Disclosure: R.D. Batson: None. A.M. Bruton: None. E.S. Pistone: None. A.J. Forrester: None. T.J. Wright: None. R.B. Pyles: None. K.M. Randolph: None. K.A. McGovern: None. C.P. Danesi: None. C.R. Gilkison: None. T.L. Wexler: None. B.E. Masel: None. K.C. Yuen: None. R.J. Urban: None. Introduction: Prior studies have reported that body mass index (BMI) negatively correlated with peak growth hormone (GH) response on the glucagon stimulation test (GST). Very little is known regarding the influence specifically of body composition and weight on peak GH response to glucagon stimulation. We sought to clarify the influence of BMI, weight and body composition on peak GH response to GST in a predominantly mild TBI adult population. Methods: A retrospective analysis of fixed-dose glucagon stimulation test (GST) results from 288 subjects at two centers was conducted. Fixed-dose GST protocols utilized 1 mg glucagon for individuals ≤90 kg and 1.5 mg for those &amp;gt;90 kg. Center A and Center B performed 240-minute and 180-minute GSTs, respectively. Multiple linear regression was used to evaluate the association between the dependent variable of peak GH and the following: BMI, weight, lean mass, fat mass, and fat percent in 5 separate models. Age and sex were added to all models and glucagon dose (1/1.5 mg) was assessed for inclusion. BMI was assessed as continuous, categorical, and binary, plus the interaction terms between them. F-tests and the coefficient of determination (adjusted R2) were used for model selection. Results: The best fit to the data was a model with age, sex, and the interaction between continuous and binary BMI (&amp;lt; or ≥30 kg/m2; N=288; adjusted R2=0.14; p&amp;lt;0.001). The range of BMI for non-obese (&amp;lt;30 kg/m2) participants was 15.8-29.9, and for obese (≥30 kg/m2) participants was 30.0-55.6. Every one-unit increase in BMI in the non-obese group was associated with a 0.54 ng/mL decrease in peak GH (95% CI: -0.82, -0.26; p&amp;lt;0.001). The association between BMI and peak GH in the obese group was non-significant. A restricted cubic spline regression model suggested the association between BMI and peak GH was nonlinear, especially for participants with BMIs between 24-30 kg/m2. Logistic regression revealed that overweight and obese individuals had increased odds of failing the GST compared to normal weight individuals. In a model adjusted for age and sex, every one-kilogram increase in weight was associated with 0.09 ng/mL decrease in peak GH (95% CI: -0.13, -0.05; p&amp;lt;0.001) but the weight model (N=288; adjusted R2=0.11; p&amp;lt;0.001) predicted peak GH less accurately than BMI. In participants with lean mass, fat mass, and fat percent data (N=50) none of the three were significantly associated with peak GH. Glucagon dose was not included in any of the models. Conclusions: In subjects with TBI who underwent GSTs, body weight was significantly associated with peak GH, but fat mass, lean mass, and fat percent were not. Additionally, BMI was negatively associated with peak GH, but only in subjects with BMIs &amp;lt;30 kg/m2. These results, although limited to a TBI population, differ from prior studies demonstrating an inverse relationship between BMI and peak GH in those with BMIs ≥ 30 kg/m2. Presentation: Saturday, July 12, 2025

Disclosure: M. Kościuszko: None. A. Buczyńska: None. K. Sobieska: None. A. Krętowski: None. A. Popławska-Kita: None.Introduction: Asprosin (ASP) a fasting-induced glucogenic hormone, plays a significant role in metabolic regulation by promoting glucose release from the liver. ASP may influence muscle mass through indirect mechanisms related to energy balance and metabolic regulation. The study aimed to assess ASP levels in relation to body weight, gender, body composition, and insulin resistance (IR) parameters. Study group: This study involved 150 participants divided into three groups: 50 with obesity (O2), 50 who were overweight (O1), and 50 healthy controls (CG). All participants underwent an oral glucose tolerance test (OGTT), with glucose, insulin and ASP levels measured at multiple time points. Body composition was evaluated using dual-energy X-ray absorptiometry (DXA). Results: ASP levels increased with excess body weight (CG: 17.8 ± 11.0 ng/ml; O1: 28.7 ± 23.2 ng/ml, p < 0.01; O2: 42.7 ± 23.9 ng/ml, p < 0.0001). No significant BMI differences were observed between male and female participants, but they differed in body composition. Men in the O1 group had higher ASP levels than women (p < 0.01). Muscle mass was higher in men (CG: p < 0.003; O1: p < 0.0001; O2: p < 0.0001), while women had higher fat mass, % adipose tissue, and gynoid fat mass (CG: p < 0.05; O1: p < 0.0001; O2: p < 0.0001). Men also had a higher resting metabolic rate (RMR) (CG: p < 0.01; O1: p < 0.0001; O2: p < 0.0001). ASP positively correlated with fat mass (O1: r = 0.60, p < 0.001; O2: r = 0.52, p < 0.001) and fat percentage (O1: r = 0.76, p < 0.001; O2: r = 0.65, p < 0.001), and negatively with muscle mass (O1: r = -0.56, p < 0.001; O2: r = -0.34, p < 0.001) and total body water (TBW) (O1: r = -0.56, p < 0.001; O2: r = -0.32, p < 0.001), suggesting ASP's role in fat metabolism and muscle breakdown. ASP was negatively correlated with RMR (O1: r = -0.57, p < 0.001; O2: r = -0.24, p < 0.005). In the O1 group, ASP negatively correlated with fasting glucose (r = -0.23, p = 0.02) and postprandial glucose at 60 (r = -0.23, p = 0.01) and 240 minutes (r = -0.28, p = 0.008), indicating its role in glucose uptake and insulin secretion. No significant ASP-glycemia correlation was observed in the O2 group. Positive correlations between ASP and fasting insulin (O1: r = 0.22, p < 0.05) and insulin secretion at 120 minutes (r = 0.39, p < 0.001) suggest ASP's involvement in hyperinsulinemia, with a stronger correlation at 60 minutes in O2 (r = 0.31, p < 0.001). Conclusion: Elevated ASP concentrations are linked to increased fat mass and reduced muscle mass, suggesting ASP as a marker of impaired body composition. Chronic ASP elevation may promote muscle wasting by disrupting the balance between protein synthesis and degradation. These results highlight ASP's significant role in obesity and IR pathophysiology, making it a potential therapeutic target for managing obesity.Presentation: Saturday, July 12, 2025

Artichoke leaf extract reduces steatosis and decreases liver size in prebariatric patients: A randomized placebo-controlled pilot trial-The "SteatoChoke-Study".

The main aim of the study was to examine the effects of a 12-week resistance training (RT) programme on HRQoL scores and physical fitness components. One hundred and fourteen older adults aged between 60 and 70 years were recruited (mean ± SD; age = 66.2 ± 3.0 years; 48.2% women) and randomly assigned to RT (n = 57; age = 66.0 ± 2.9 years; 48.5% women) or control (CON; n = 57; age = 66.4 ± 3.1 years; 47.9% women) groups. Baseline and follow-up data included Health-related Quality of Life (HRQoL) questionnaire, and Senior Fitness Test. No significant differences in outcome variables between the two groups were observed (p&amp;gt;.05). After a 12-week intervention, RT group improved physical (80.5%, ES = 4.7), psychological (60.2%, ES = 3.0), social (39.1%, ES = 1.5), and environmental (51.7%, ES = 3.9) components of HRQoL. Over the 12 weeks, RT group decreased body-mass index (-9.7%, ES = -0.4), fat mass percentage (-11.4%, ES = -0.6), and visceral fat (-17.2%, ES = -0.8) and increased muscle mass percentage (13.2%, ES = 1.0), muscular (20.9% and 12.4%, ES = 0.7 and 0.4) and cardiorespiratory fitness (7.2%, ES = 0.2), flexibility (62.5% and 34.6%, ES = 0.3), and agility (-14.8%, ES = -1.0). No significant time changes in the CON group were observed. A 12-week RT programme increases HRQoL and overall physical performance in older adults, making RT an effective intervention method for improving broad-spectrum HRQoL and physical fitness components.

Associations of weekday-to-weekend and day-to-day sleep differences with adiposity-related measures in children and adolescents: A systematic review and meta-analysis.

ObjectiveThis study aims to investigate the association between the retinal artery to vein ratio (AVR) and body fat distribution, and to further evaluate the potential beneficial effects of optimized fat distribution on systemic vascular health.MethodsA total of 2,698 participants aged 18 to 80 from Lanxi cohort were enrolled. After applying inclusion and exclusion criteria, 2,045 participants were retained for the final analysis. Retinal vessel images were obtained through fundoscopy, and retinal AVR was automatically calculated using a clinically validated AI algorithm. Body fat was assessed by dual-energy x-ray absorptiometry (DXA). Adjusted multivariate linear regression models were used to identify the associations of retinal AVR with fat distribution.ResultsRetinal AVR was negatively associated with waist-hip ratio (WHR), android fat mass percentage, android to gynoid fat ratio, and trunk fat mass percentage. Similar trends were observed when fat distribution indicators were categorized into quartiles (P for trend < 0.05). When stratified by age, a similar significant association was observed in the 45–60 age group.ConclusionsRetinal AVR was associated with fat distribution, with particularly correlations observed in middle-aged populations and those with metabolic abnormalities. And these associations differ based on the location of fat depots, indicating that exercise-induced fat redistribution is associated with vascular health.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12886-025-04408-x.

Methotrexate (MTX) is essential for treating lymphoblastic leukemia, but high doses (5g/m2 corporal surface) can cause significant gastrointestinal, renal, hepatic, and hematological toxicity. Body composition, particularly high body fat mass, can function as a third space and may increase toxicity by prolonging the drug's circulation time. To analyze the associations between body composition (body fat mass, visceral fat area, and skeletal muscle mass) and the incidence of MTX toxicity in patients with acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma. A cohort of patients aged 6-18 years diagnosed with ALL and lymphoblastic lymphoma who received high-dose MTX without prior toxicity was included. Patients with preexisting renal failure or liver failure before MTX administration were excluded. Body composition was assessed using a multifrequency bioimpedance device. Regarding MTX toxicity, 30.2% of events occurred early, and this figure increased to 58.7% for late toxicity. Patients with a visceral fat area (VFA) ≥47 cm2 had a significantly higher risk of late toxicity (RR 2.8 (1.3-5.5), p = 0.01), as did those with high body fat mass (RR 2.0 (1.1-3.4), p = 0.01). For severe late toxicity, a VFA ≥47 cm2 was strongly correlated (RR 5.6 (1.3-22.6), p = 0.003), and high body fat mass remained a significant risk factor (RR 2.3 (1.03-5.5), p = 0.03). No significant associations were found with low phase angle, low skeletal muscle index, or overweight body mass index. A VFA ≥ 47 cm2 and a high percentage of body fat mass were associated with an increased risk of late MTX toxicity and severe late toxicity.