PURPOSE: The objective of the present study is to investigate the relationships between body composition, nutritional profile, muscular fitness (MF) and bone health in a sample of children and adolescents from Colombia. METHODS: Participants included 1,118 children and adolescents (54.6% girls). Broadband ultrasound attenuation (BUA) was obtained by using quantitative ultrasound technique at the calcaneus as a marker of bone health. Body composition (fat mass and lean mass) was assessed using bioelectrical impedance analysis. Furthermore, height, weight, waist circumference and Tanner stage measured and body mass index (BMI) was measured. Standing long-jump and isometric handgrip dynamometry were used as indicators of lower and upper body muscular fitness, respectively. Also, a muscular index score was computed by summing up the standardised values of both standing long-jump and handgrip strength. Dietary intake and degree of adherence to the Mediterranean diet were assessed by a 7-day recall questionnaire for food frequency and the Kidmed questionnaire, respectively. Poor bone health was considered using a Z-score cut off of ≤ -1.5. RESULTS: Once the adjustment was performed (by age and Tanner stage), the predisposing factors of having a c-BUA z-score ≤ − 1.5 SD included: included: being underweight [OR 2.30 (95% CI 1.53 to 1.69)], or being obese [OR 0.17 (95% CI 0.04 to 0.69)], having an unhealthy lean mass [OR 2.51 (95% CI 1.74 to 3.60)], unhealthy levels of fat mass [OR 0.46 (95% CI 0.29 to 0.74)], unhealthy SLJ performance [OR 1.55 (95% CI 1.09 to 2.19)], unhealthy handgrip performance [OR 3.77 (95% CI 2.29 to 6.20)], and unhealthy muscular index score [OR 2.22 (95% CI 1.42 to 3.47)]. CONCLUSIONS: In conclusion, body composition and MF influence bone health on a sample of children and adolescents from Colombia. Thus, promoting strength adaptation and preservation in Colombian youth will help to maximize bone health, an important protective factor against osteoporosis later in life.