<p>Assessment of Age-Induced Changes in Body Fat Percentage and BMI Aided by Bayesian Modelling: A Cross-Sectional Cohort Study in Middle-Aged and Older Adults</p>

Abstract

Background Loss of fat-free mass (FFM) and gain in body fat (BF) are the key disability risk factors, also instrumental in perpetuating already existing functional disorders. Obesity construed in terms of body mass index (BMI) values, in view of undesirable gain in BF, is a risk factor for cardio-metabolic disorders. Both detrimental processes clearly evidence a scope of involutionary changes characteristic of an aging population, also standing for one of its greatest burdens. Purpose The present study aimed to assess the changes in body composition (BC), in conjunction with the relationship between BF% and BMI, for defining overweight and obesity status in middle-aged and older adults, against the select indicator variables under study. Materials and Methods The study involved 4799 individuals (33.7% men), PONS Project participants, aged 43–64 years. BF% was measured with the aid of bioelectrical impedance analysis (BIA) method. Age-induced changes in BC were determined against BF%, fat mass (FM), FFM, BMI, fat mass index (FMI), and fat-free mass index (FFMI). The relationship between BF% and BMI was established with the aid of Bayesian regression models, adjusted for gender and age. Results In both genders, BF% increased with age at a similar annual rate. The reduction of FFM was noted mainly in men, which in conjunction with BF% gain ensured BMI stability. The increase in BF% in women with stable FFM affected an increase in BMI. Regardless of the BMI threshold, the anticipated (predicted) BF% increased with age in both genders. Conclusion Monitoring of BC is of particular importance in older adults, in view of appreciably better characteristics of both the short- and long-term health predictors, as well as overall potential for developing specifically targeted, effective health interventions.

The association of the age, period, and birth cohort with 15-year changes in body mass index and waist circumference in adults: Tehran lipid and glucose study (TLGS)

“…Furthermore, age affects the distribution of the adipose tissue, with more intra-abdominal and visceral adipose tissues vs. peripheral subcutaneous fat mass being observed in the elderly [ 22 ]. Besides, spinal degenerative changes and a consequent reduction in height during the aging process could explain the increase of WC despite decreased or sustained weight in this age group [ 23 ].…”

Association of Regular Leisure-Time Physical Activity with Self-Reported Body Mass Index and Obesity Risk among Middle-Aged and Older Adults in Taiwan

“…The present study has some limitations. First, the health status, LTPA, and BMI assessments were based on self-reported questionnaires and therefore have considerable potential for misclassification [ 13 , 26 , 27 , 34 ]. However, the large sample size is the major strength of this study, which provides an idea of how cross-sectional changes occur in LTPA and obesity status among middle-aged and older adults.…”

“…Age-induced changes in body fat percentage and BMI increase the risk of obesity, cardiometabolic diseases, and disability [ 13 ]. According to the WHO, the terms “aging society” and “aged society” refer to societies with ≥7% and ≥14% of individuals aged ≥65 years, respectively [ 14 ].…”

The Influence of the Age, Period, and Cohort Effects on 15-year Changes in Weight and Waist Circumference in Adults: Tehran Lipid and Glucose Study (TLGS)

“…Furthermore, age affects the distribution of the adipose tissue, with more intra-abdominal and visceral adipose tissues vs. peripheral subcutaneous fat mass being observed in the elderly (21). Besides, spinal degenerative changes and a consequent reduction in height during the aging process could explain the increase of WC despite decreased or sustained weight in this age group (22).…”