Relationship among three field methods of estimating percent body fat in young adults

A certain amount of fat is essential for normal body functioning and subcutaneous fat is usually considered to represent a good estimate of total body fat. It is uncertain, however, whether the different field methods of estimating percent body fat will give similar values, considering the variations in the methods used in the assessment. This study sought to determine the relationships among percent body fat value estimates obtained using skinfold thickness (ST), body circumference (BC), and bioelectrical impedance analysis (BIA).This cross-sectional survey involved purposefully selected participants from the University College Hospital, Ibadan community. Skinfold thickness, body circumference and bioelectrical impedance analysis were measured according to the International Standards for Anthropometric Assessment protocol. These were then used to estimate percent body fat. The relationship among the different percent body values were sought using Pearson correlation coefficients. The participants included 75 males and 93 females with a mean age of 25.5±5.0 years. Using the BMI classification of body weight, 50% had desirable weight, 23.8% were underweight, 15.6% were overweight, and 10.7% were obese. The mean percent body fat scores obtained from ST, BC and BIA were 19.8±6.3%, 18.5±7.1% and 18.4±8.0% respectively. Females had significantly higher percent body fat in all the estimates than their male counterparts. There were significant correlations between percent body fat obtained using ST and BIA (r = 0.86, p<0.05), BC and ST (r = 0.90, p<0.05), and BIA and BC (r = 0.74, p<0.05). Positive and significant correlations exist among percent body fat obtained using the skinfold thickness, body circumference and bioelectrical impedance analysis methods. Therefore, all these methods are acceptable for clinical estimation of percent body fat. This study shows that the estimation of percent body fat can be done using both sophisticated and simple instruments. Key words: Body mass index, skinfold thickness, body circumference, bioelectrical impedance analysis