Accuracy and Predictive Capability of Body Mass Index in Evaluation of Obesity and Body Fatness Level in Police Officers

Abstract

This study evaluated the accuracy and predictive value of body mass index (BMI) in evaluation of obesity and body fatness. Data on BMI and percent body fat (PBF) were collected on 953 male police officers who were allocated into age groups: 20-29 years, 30-39 years, and 40-49 years. BMI > 30.0 kg/m2 and PBF > 25% were classified as obese, and those with lower values were classified as non-obese. Chi-square was used to evaluate the accuracy in classification in obese and non-obese when officers’ BMI was matched to PBF. Pearson’s correlation and linear regression analyses determined the prediction value of BMI. Chi-square revealed significant difference in obesity prevalence when evaluated by BMI and PBF, with classification accuracy of 44.5%-71.8%, depending on age. BMI had moderate prediction value of body fatness. If the assessment of PBF is not attainable, BMI needs to be used carefully as it is likely to underestimate obesity among police officers.

Accuracy of Body Mass Index and Obesity Status in Police Trainees

“…As an indirect method of measuring obesity, BMI does not account for the fact that muscle mass decreases with age, while body fat increases, but a person’s weight and height do not necessarily demonstrate the same changes [ 32 ]. Although BMI is the least expensive method and most practical measure, it does not seem to be the most ideal indicator of obesity for these PTs or among other samples of POs [ 2 , 11 , 16 ]. A key reason is that BMI cannot distinguish between fat mass and lean mass in categorizing obesity [ 33 ].…”

“…They were all participating in physical training program at the police college campus, twice a day for five consecutive days a week, followed by a two-day rest period (weekend). Body composition was assessed using a multichannel bioelectrical impedance analysis in a laboratory setting, the InBody 370 machine (InBody, Seoul, South Korea), following previously established procedures [ 11 , 25 ]. The Bioelectrical Impedance Analysis (BIA) method is based on the fact that the human body consists of conductors and non-conductors.…”

“…Body mass index (BMI) levels have been frequently correlated with physical fitness and used to evaluate body composition status in the police workforce [ 1 , 10 , 11 , 12 , 13 ]. Although BMI is the most frequently used method to assess body composition status, this method has been criticized because BMI does not always reflect true body fatness and has some limitations in assessing people with low muscle and high body fat, where these individuals have increased body fat and normal BMI [ 2 , 8 , 11 ]. Muscular individuals can also be misclassified as overweight or obese instead of normal weight [ 14 , 15 ].…”

“…Several studies have shown discrepancies between BMI, PBF and PSMM in assessing obesity among police forces [ 2 , 11 , 16 ]. Heinrich et al [ 2 ] assessed the accuracy of BMI classification in relation to PBF among Russian POs.…”

“…Their study found that BMI underestimated obesity rates when compared with PBF, and direct measurement of PBF could be more helpful than using estimation methods such as BMI. Similarly, Kukić et al [ 11 ] compared whether the BMI misclassified the obesity rate of POs when compared to PBF, and the conclusion was also that BMI underestimated obesity among POs. They also examined the accuracy of BMI in evaluating obesity and found a moderate prediction value as the classification accuracy was 44.5–71.8%, depending on the age of the POs.…”