Tri-ponderal mass index (TMI) and fat mass index (FMI) have been proposed as alternative approaches for assessing body fat since BMI does not ensure an accurate screening for obesity and overweight status in children and adolescents. This study proposes thresholds of the TMI and FMI for the prediction of metabolic syndrome (MetS) in children and young people. For this purpose, a cross-sectional study was conducted on 4673 participants (57.1% females), who were 9–25 years of age. As part of the study, measurements of the subjects’ weight, waist circumference, serum lipid indices, blood pressure and fasting plasma glucose were taken. Body composition was measured by bioelectrical impedance analysis (BIA). The TMI and FMI were calculated as weight (kg)/height (m3) and fat mass (kg)/height (m3), respectively. Following the International Diabetes Federation (IDF) definition, MetS is defined as including three or more metabolic abnormalities. Cohort-specific thresholds were established to identify Colombian children and young people at high risk of MetS. The thresholds were applied to the following groups: (i) a cohort of children where the girls’ TMI ≥ 12.13 kg/m3 and the boys’ TMI ≥ 12.10 kg/m3; (ii) a cohort of adolescents where the girls’ TMI ≥ 12.48 kg/m3 and the boys’ TMI ≥ 11.19 kg/m3; (iii) a cohort of young adults where the women’s TMI ≥ 13.21 kg/m3 and the men’s TMI ≥ 12.19 kg/m3. The FMI reference cut-off values used for the different groups were as follows: (i) a cohort of children where the girls’ FMI ≥ 2.59 fat mass/m3 and the boys’ FMI ≥ 1.98 fat mass/m3; (ii) a cohort of adolescents where the girls’ FMI ≥ 3.12 fat mass/m3 and the boys’ FMI ≥ 1.46 fat mass/m3; (iii) a cohort of adults where the women’s FMI ≥ 3.27 kg/m3 and the men’s FMI ≥ 1.65 kg/m3. Our results showed that the FMI and TMI had a moderate discriminatory power to detect MetS in Colombian children, adolescents, and young adults.

Fat-to-muscle ratio has been proposed as an alternative approach for assessing body fat. The objective of this study was to explore fat-to-muscle ratio thresholds in metabolic syndrome (MetS) diagnosis; it was hypothesised that the fat-to-muscle ratio is a good predictive indicator of MetS in a large population of young Colombian adults. For this purpose, a cross-sectional study was conducted on 1416 subjects (66.6% female), aged from 18.1 to 25.1. As part of the study, measurements of the subjects’ anthropometric indicators, serum lipid indices, blood pressure, and fasting plasma glucose were taken. Body composition was measured through bioelectrical impedance analysis (BIA). A new variable (ratio of fat mass to muscle mass, in kg) was calculated. Following the International Diabetes Federation (IDF) definition, MetS includes three or more metabolic abnormalities. Receiver operating characteristic (ROC) curves and logistic regression determined the discriminatory ability of the fat-to-muscle ratio to predict MetS. According to the IDF, the best fat-to-muscle ratio cut-off point for detecting MetS in men was 0.225 kg, with an area under the curve (AUC) of 0.83, sensitivity of 80%, and specificity of 70%. For women, the fat-to-muscle ratio cut-off point was 0.495 kg, the AUC was 0.88, and the sensitivity and specificity were 82% and 80%, respectively. In conclusion, our results showed that the fat-to-muscle ratio cut-off points from ROC analyses demonstrate good discriminatory power for detecting MetS in young Colombian adults.

Objetivo: evaluar la relación entre la percepción de las barreras para la práctica de la actividad física (AF) con la presencia de obesidad abdominal (OA) en universitarios de Colombia.Métodos :estudio descriptivo y transversal en 5.663 sujetos entre 18 y 30 años de edad (3.348 hombres), pertenecientes a tres ciudades de Colombia. Se midió la circunferencia de cintura (CC) como indicador de OA y el riesgo se clasificó según valores de referencia internacionales. La autopercepción de barreras se determinó con el cuestionario Barriers to Being Active Quiz (BBAQ-21) validado en Colombia. Se calcularon razones de prevalencia (RP) entre cada dominio del cuestionario y clasificación de OA.Resultados: la prevalencia de obesidad abdominal fue del 10,4% con diferencias por sexo (7,3% hombres vs.12,6% mujeres p < 0,01). La "falta de tiempo", la "influencia social" y la "falta de habilidades" fueron las barreras más prevalentes para cesar la práctica de AF en el grupo de entrevistados con OA en ambos sexos. Al comparar los estudiantes con CC saludable, la RP de presentar OA fue mayor en el grupo de mujeres que en hombres en los dominios del cuestionario BBAQ-21 "falta de tiempo" (RP = 1,33 [IC 95% 1,11-1,60]) vs.(RP = 1,14 [IC 95% 1,03-1,26]) y "falta de recursos" (RP = 1, 93 [IC 95% 11,67-2,24])vs. (RP = 1,83 [IC 95% 1,68-1,99]), respectivamente.Conclusión: una mayor autopercepción de las barreras para realizar AF se relacionó con mayor frecuencia en el grupo con OA en universitarios de Colombia.