Table 1

Effects of body mass index (BMI) or body fat percentage (%BF) on injury risk in children and young adults

SubjectsAge (years)NType of InjuryEffect of BMI or %BFCommentsReference
All children9 to 17 ♂♀2363All injuriesObese versus non-obese OR 1.42 (1.13 to 1.79) p = 0.003Retrospective recall of injuries in previous year; injury prevalence 44.3% in obese versus 35.9% in non-obese; injuries in sport and non-sport activities combinedBazelmans et al13
All children6 to 11 ♂♀938Dental injuriesObese versus non-obese OR 1.45 (1.08 to 1.94) p = 0.01Retrospective comparison of evidence of prior dental injury in obese (30.8% injured) versus non-obese (20% injured; prior exposure to high risk activities (eg, sport) was protectivePetti et al14
All children5 to 19 ♂♀180Ankle sprainsObese* versus normal weight OR 3.26 (1.86 to 5.72) p<0.001Case control study of prevalence of obesity in emergency department cases (ankle sprain) versus control (fever, headache, sore throat); 36% of ankle sprain group were obese versus 20% in control groupZonfrillo et al17
All children11 to 18 ♂♀3294All injuries♀Obese versus non-obese OR 2.61 (1.16 to 5.91) p<0.05Prospective comparison of injuries occurring at school in obese versus non-obese girls and boys; ♂no effect of BMI on injury risk; ♀effect not specific to sportChau et al15
American football15 to 18 ♂152Ankle sprainsOverweight* versus normal weight OR 2.01 (0.5 to 8.5);Prospective comparison of injuries per 1000 exposures in normal weight (0.52 injuries), overweight (1.05) and obese (2.03) football players; risk increased 19 fold with combination of obesity and previous ankle sprainTyler et al5
Obese* versus normal weight OR 3.9 (1.0 to 15.1); linear effect p = 0.04
American football15 to 18 ♂98All injuriesObese* versus non-obese OR 2.3 (CI not reported) p<0.05Prospective comparison of injuries per player per season in obese (0.53 injuries) versus non-obese (0.23); body mass >90 kg versus <90 kg OR 2.5Kaplan et al22
American football8 to 15 ♂653All injuriesNoneProspective comparison of overweight and obesity prevalence in injured players (40.6%) versus the total sample (42.6%); no definition of injury, no measure of exposureMalina et al4
American football9 to 14 ♂678All injuriesNoneProspective study of injury incidence (total 10.4 per 1000 exposures); BMI compared between injured and uninjured players in each age group; injured 9–10 years old had lower BMI (p = 0.05)Malina et al3
American football14 to 19 ♂215Lower extremity injuriesBMI⩾30 versus <30 OR 2.7†Prospective comparison of injuries per 1000 h across BMI cut-off points (total injuries 5.7); only linemen studied, mean BMI 30.7, %BF 25.7%Gómez et al18
%BF⩾25 versus <25 OR 2.0† (CI not reported) p<0.05
High school athletes14 to 19 ♂♀2721All injuriesBMI 50–90th pct versus 10th pct OR 1.52 (1.06 to 2.17)‡Retrospective recall of prior injury compared across BMI groups; 65.7% of subjects reported an injury in prior year; BMI>90th percentile no effectRose et al16
Military recruits18 (SD 3) ♂♀1210All injuriesOverweight* versus normal weight OR 1.48 (1.12 to 1.96)Retrospective comparison of injury prevalence between normal weight, overweight and obese subjects; most obese subjects played American footballBillings19
Obese* versus normal weight OR 3.44 (1.94 to 6.09) p<0.05
Military recruits95% 18 to 22 ♂912All injuriesUpper BMI quintile versus Middle quintile RR 1.91 (1.27 to 2.87) p<0.01Prospective comparison of injuries per 100 conscript-months in BMI quintiles; BMI higher in older subjects, results not directly applicable to childrenHeir and Eide20
Military recruits21 (SD 4) ♂310All injuries♂ upper BMI quartile versus 2nd quartile RR 3.4 (1.3 to 9.4) p = 0.02Prospective comparison of injury prevalence across BMI quartiles (Q1 25.8%, Q2 9.4%, Q3 13.8%, Q4 32.3% injured); ♂%BF upper quartile RR 2.4 p = 0.09; ♀no effect of BMI or %BFJones et al21
20 (SD 3) ♀

  • *The terms “overweight” and “obese” are used here instead of the terms “at risk of overweight” and “overweight,” which were used in the original reference (see earlier introductory section for explanation and definitions).

  • †Values estimated from figures.

  • ‡Values averaged from reported data for subgroups.

  • OR, odds ratio; Pct, percentile; RR, relative risk (95% CIs in parentheses).