Fat–fat-free index in body mass assessment in young people

Abstract

The study aimed to personalize the classification of body weight using the fat–fat-free (FFF) index with the percentage of body fat and to develop classification standards for the FFF index for men aged 18–25 years. Moreover, 1,642 adolescents (1,200 ♀) were examined. Using body composition analyzers, weight was determined, as well as overall and segmental body composition. Based on the obtained values for fat mass and fat-free tissue mass, an overall FFF index was calculated. According to the BMI classification, 9% of ♀ and 6% of ♂ are underweight, 29% of ♀ and 13% of ♂ are overweight, and 5% of the subjects are obese. Women and men classified in the same group according to BMI differed statistically significantly in terms of body weight, FM%, and FFM. In contrast to BMI and FM%, the FFF used takes into account the ratio of fat mass to fat-free tissue and muscle tissue mass. The proposed classification of FFF was made taking into account the differences that arise with sexual development and physiological changes occurring in ontogeny. Assessment of body mass using the FFF index should be used as part of preventive screening for the early diagnosis and prevention of overweight and thus many chronic diseases for which overweight or obesity is a risk factor.

The Incidence of Body Posture Abnormalities in Relation to the Segmental Body Composition in Early School-Aged Children

“…Examinations based on the BIA were used to estimate the general and segmental fat (fat mass [%] and [kg] FM%, FM) and fat-free components (fat-free mass in [kg] FFM, muscle mass in [kg] MM). FM and FFM were used to calculate the general and segmental fat–fat-free (FFF) index (right leg—RL FFF, left leg—LL FFF, right arm—RA FFF, left arm—LA FFF, trunk—TR FFF) [ 1 , 3 , 31 , 32 , 33 ].…”

“…The commencement of school education, accompanied by a lifestyle change, increases the risk for posture defects and abnormal body mass [ 1 , 2 ]. Many researchers point out that one in five children aged 7–10 has excess body mass, which may result from the prenatal stage and from the lifestyle during preschool years [ 3 , 4 , 5 , 6 , 7 , 8 ].…”

“…During that stage, the amount and distribution of FM begin to differ based on the sex (female—15–25%, male—13–20%); at the same time, the individual’s anatomical proportions change and the final body type takes shape. After the end of puberty, the weight gain rate slows down and body proportion stabilizes [ 1 , 9 , 10 ]. Many authors emphasize that the weight cut and the BMI calculated on its basis are not sufficient values to assess the occurrence of abnormal body weight.…”

“…More and more often, the authors consider the importance of fat mass in the development of overweight and obesity [ 11 , 12 , 13 , 14 , 15 , 16 ]. That is why it is so important to use bioelectrical impedance analysis (BIA) to assess the content of fat and fat-free components [ 1 , 3 , 16 , 17 , 18 , 19 ].…”

“…Posture defects are common and can be observed in children of all ages. The periods of rapid growth coincide with the change in the lifestyle of a child aged 5–7, and the second period is during adolescence (aged 12–16) [ 1 , 7 ]. One of the risk factors for poor posture is excess body weight.…”