The Association between Body Mass Index and Muscular Fitness in Chinese College Freshmen

[Comparative research on the relationship between body mass index and physical fitness index among the Uygur, Kazakh and Han ethnic college students]

OBJECTIVE

To understand the nutritional status and physical fitness of the Uygur, Kazak and Han ethnic college students, and to investigate the nonlinear relationship between BMI and physical fitness indexes in different ethnic groups.

METHODS

A total of 3 600 Uygur, Kazakh and Han students majoring in non-sports in a university in Xinjiang Uygur Autonomous Region in 2021 were selected by stratified random cluster sampling method. Height, weight, vital capacity, 50 m running, standing long jump, sit-and-reach, sit-up/pull-up and endurance running were measured. Body mass index (BMI), standardized Z score of each test score and physical fitness index (PFI) were calculated. The data were analyzed by Chi-square test, single factor analysis of variance, and nonlinear quadratic regression.

RESULTS

Prevalences of overweight (16.00%) and obesity (8.08%) of the Han college students were significantly higher than those of the Uygur (11.83% and 4.08%) and Kazakh (13.58% and 4.58%). Prevalence of low weight in the Uygur (11.92%) was the highest, and the lowest was the Kazakh (9.75%). There were significant differences in the prevalence of BMI classification among the three ethnic groups boys and girls (all P < 0.05). There were significant differences in PFI among college students of different BMI levels in the Uygur, Kazakh and Han ethnic college students (all P < 0.05), and the PFI of normal weight group was higher than the other weight groups in general, and the overweight group was higher than the obese group, but some ethnics showed the highest PFI in the low weight group. The non-linear quadratic regression results showed that the curves of the Uygur boys and girls and the Kazakh boys were inverted "J" shaped, and the PFI increased and then decreased with the increase of BMI, while the rest of the curves were arc-shaped, and the PFI decreased with the increase of BMI.

CONCLUSION

Overweight obesity in the Uygur, Kazakh and Han ethnic college students brings about a decrease in physical fitness, but Kazakh low weight male and female and Han low weight grils have better physical fitness than the normal weight groups. Focusing on improving the physical fitness of Uygur low-weight and high-weight boys and Han high-weight girls could effectively reduce the differences in physical fitness of college students in different weight levels and ethnic groups.

Sarcopenic obesity in nursing home residents: a multi-center study on diagnostic methods and their association with instrumental activities of daily living

BACKGROUND

Sarcopenic obesity (SO) in nursing home residents is rarely studied. We aimed to evaluate and compare the prevalence and consistency of different SO diagnostic methods and to investigate which criterion demonstrated a stronger association with instrumental activities of daily living (IADL) disability.

METHODS

We consecutively recruited older adults aged ≥ 60 years, residing in 15 nursing homes in Zigong City, China. Sarcopenia obesity was defined according to the European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity criteria (SOESPEN), recommending skeletal muscle mass (SMM) adjusted by body weight (SMM/W) to identify low muscle mass. Further, we adapted ESPEN criteria (SOESPEN-M) by employing SMM adjusted by body mass index (SMM/BMI).

RESULTS

We included 832 participants (median age 73.0 years, 296 women). The prevalence of SOESPEN and SOESPEN-M was 43.5% and 45.3%, respectively. SOESPEN showed good consistency with SOESPEN-M (Cohen's kappa = 0.759). More than one-third of participants in the normal weight group were diagnosed with SOESPEN or SOESPEN-M. Even within the underweight group, the prevalence of SOESPEN and SOESPEN-M was 8.9% and 22.2%, respectively. Participants with IADL disability had significantly lower SMM/W and SMM/BMI, but higher fat mass percentage of body weight (FM%) than participants without IADL disability. After full adjustment for potential confounders, SOESPEN-M (OR 1.68, 95% CI 1.21 to 2.32), but not SOESPEN (OR 1.28, 95% CI 0.93 to 1.75), remained significantly associated with IADL disability.

CONCLUSIONS

Both SOESPEN and SOESPEN-M showed a high prevalence among nursing home residents, even among individuals with underweight or normal weight. While SOESPEN had a good consistency with SOESPEN-M, only SOESPEN-M was independently associated with IADL disability. Screening and diagnosis of SO should be conducted in nursing home residents irrespective of BMI.

The relationships between body mass index, reciprocal ponderal index, waist-to-height ratio, and fitness in young adult males

Background

Anthropometric measures such as the body mass index (BMI), reciprocal ponderal index (RPI), and waist-to-height ratio (WHR) have been proposed as predictors of physical fitness. This study aimed to identify the differences in explanatory capacity and fit of BMI, RPI, and WHR on physical fitness, which involves jumping, sprinting, change of direction, and aerobic capacity, by adjusting the polynomial regression.

Methods

A sample of 297 healthy, recreationally active male university students between 18 and 20 years old was recruited for this study. Anthropometric measurements (height: 174.09 ± 6.27 cm, weight: 78.98 ± 20.27 kg, waist circumference: 93.74 ± 14.56 cm) were taken for each participant. Jumping tests (squat jump, countermovement jump), sprinting tests (20 m sprint), agility tests (agility T-test), and aerobic/endurance tests (6 min walk test, VAM-EVAL test) were performed. Nonlinear quadratic regression models were used to assess the relationship between the jump, sprint, and fitness test scores and the anthropometric indices. The models were compared based on R-squares and Bayesian Information Criterion (BIC). The significance level was set at p < 0.05.

Results

The results showed that all the indices predicted a portion of the variance because all variables and index relationships were significant. Regarding the fitted models, the Bayesian Information Criterion showed that BMI was the best indicator of performance, although the RPI was better for VO2max.

Conclusion

These findings may be of great interest to practitioners because it appears that anthropometric measures can be used to predict physical fitness in certain tests although the accuracy raises any concerns.

Body Mass Index and Physical Fitness among Chinese Adolescents Aged 15-18: A Cross-Sectional Study of Gender Differences

OBJECTIVE

The aim of this study is to examine the relationship between varying levels of obesity and physical fitness test scores among Chinese adolescents, while also investigating gender differences in physical fitness and overall health. Data on height, weight, 50 m sprints, 1000/800 m runs, standing long jumps, sit and reach exercises, pull-ups/bent-leg sit-ups, and additional variables were collected from the DYH health database. Physical fitness indicators were evaluated based on the revised 2014 National Physical Fitness Standards for Students, and scores were assigned accordingly. An ordinal logistic regression (ologit) model was employed to analyze the relationship between body mass index (BMI) and physical fitness.

RESULTS

(1) Normal-weight boys achieved significantly higher physical fitness test scores than boys in other weight categories. (2) Underweight and normal-weight girls obtained significantly higher physical fitness test scores compared to overweight and obese girls, with underweight girls scoring slightly higher than those with a normal weight.

CONCLUSIONS

(1) There is a significant non-linear relationship between BMI levels and physical fitness test scores. (2) Gender differences were observed in physical fitness and overall health outcome. (3) The findings indicate an inverted U-shaped association between BMI and physical fitness among boys, while girls displayed an inverse relationship. This could be attributed to the cultural association between thinness and beauty among girls in China.

Excess Weight in Relation to Lifestyle Habits in Spanish First-Year University Students: Differences between Pre- and Post-COVID-19-A Serial Cross-Sectional Study Based on uniHcos Project

The objective of this research was to study the relationship between the body weight and diet, physical activity, and other habits among freshmen students by sex, and to determine whether these habits have changed during the post-era of the COVID-19 pandemic. A serial cross-sectional study with data from 11 Spanish universities was carried out. In total, 10,096 first-year university students (73.2% female, mean age = 19.0 ± 1.5 years) completed an online self-administered questionnaire between 2012 and 2022. For some analyses, questionnaires were categorized by the year in which the survey was filled out as Before COVID-19, Lockdown, and New Normal. In total, 72.9% of participants were within the normal weight range, and 17.7% of men and 11.8% of women were overweight (p < 0.001). The students who did not meet the WHO criteria of physical activity, spent more than 7 h per day sitting, and skipped breakfast had a higher prevalence of obesity (p < 0.05). According to the period of study, the prevalence of overweight/obesity Before COVID-19 was 16.1% (95% CI: 15.4-16.9%), while in Lockdown the prevalence was significantly higher (20.2, 95% CI: 17.1-23.8) and in New Normal it was 18.9% (CI: 15.7-22.5). Moreover, the study suggests that during the Lockdown period, there was a reduction in the practice of physical activity and an increase in the prevalence of a healthy diet. For all these, it is necessary to propose public health interventions that improve the lifestyles of university students.