Body mass index, ideal weight and percentage of body fat in people of different age groups

Abstract

The objective is to compare BMI with the percentage of body fat and ideal weight, to supplement BMI in the diagnosis of obesity, from a group of adults. METHODS: descriptive, cross-cutting, prospective and correlational study, in a sample of 797 adults between 17 and 96 years old, attended in different clinical centers of Caracas, between 2015 and 2018. The variables are: age, weight, size and BMI was calculated, percentage of body fat (BFP) and ideal weight (IW). They were classified by sex, age group and BMI in normality and obesity.  Two formulas were used for BFP: Deurenberg and Regression; and three formulas for IW: Lorenz, Ramirez-Lopez et al and Broca. Descriptive measures, association, correlation, average comparison and normality test were obtained, using Excel software, Epidat.2. RESULT: BMI and BFP averages increase to 40 years and decrease to age 79, the variables Size – IW Broca, and BMI- BFPR correlate well (r>0.75). The average BMI, BFPD, BFPR, IW Broca and IW Lorenz, depending on gender, are significant (p<0.000); for BMI, in Normality and Obesity, the weight averages, BMI, BFPD and BFPR are higher in the Obesity group, and significant (p<0,000). The Shapiro-France normality test found that the distribution of BMI, BFPD, BFPR and IW Lorenz, comes from a normally distributed population (p< 0.000). CONCLUSIONS: BMI even though it is most commonly used to diagnose obesity, it classifies normally, those with a high percentage of body fat.