Application of body mass index adjusted for fat mass (BMIfat) obtained by bioelectrical impedance in adults

Introduction: Body mass index (BMI) has been one of the methods most frequently used for diagnose obesity, but it isn't consider body composition. Objective: This study intends to apply one new adiposity index, the BMI adjusted for fat mass (BMIfat) developed by Mialich, et al. (2011), in a adult Brazilian sample. Methods: A cross-sectional study with 501 individuals of both genders (366 women, 135 men) aged 17 to 38 years and mean age was 20.4 ± 2.8 years, mean weight 63.0 ± 13.5 kg, mean height 166.9 ± 9.0 cm, and BMI 22.4 ± 3.4 kg/m². Results and discussion: High and satisfactory R2 values were obtained, i.e., 91.1%, 91.9% and 88.8% for the sample as a whole and for men and women, respectively. Considering this BMIfat were developed new ranges, as follows: 1.35 to 1.65 (nutritional risk for malnutrition), > 1.65 and ≤ 2.0 (normal weight) and > 2.0 (obesity). The BMIfat had a more accurate capacity of detecting obese individuals (0.980. 0.993, 0.974) considering the sample as a whole and women and men, respectively, compared to the traditional BMI (0.932, 0.956, 0.95). Were also defined new cut-off points for the traditional BMI for the classification of obesity, i.e.: 25.24 kg/m² and 28.38 kg/m² for men and women, respectively. Conclusion: The BMIfat was applied for the present population and can be adopted in clinical practice. Further studies are needed to determine its application to different ethnic groups and to compare this index to others previously described in the scientific literature.

Beliefs about obesity and their relationship with dietary restriction and body image perception

The reviewed literature provides evidence that beliefs about the causes of obesity may actually have an influence on eating habits. In this work we wanted to analyze the relationship that may exists between beliefs about obesity, dietary restraint and body image perception. For that purpose, 258 female and male students of a High School and Occupational Training School in Seville (Spain) were recruited to conduct the study. According to our results, it was found that beliefs about obesity were positively related with dietary restraint and body image perception. Additionally, it was found that people high in beliefs about the controllability of the weight scored more in dietary restraint and body image perception than participants that did not believe that obesity was under personal control. No differences were found in Body Mass Index. Finally, it is suggested, according to the results that we found, that in order to be effective, public health campaigns may need to target people's beliefs just as much as they target their behaviours.