1,721,179 research outputs found
Individual differences in apparent energy digestibility are larger than generally recognized
No full textDisturbances in energy balance are responsible for 2 of the world's major health problems: obesity and protein-calorie malnutrition. Even small positive or negative excursions in energy balance lead to relatively large changes in body weight over prolonged time period
Are adult body circumferences associated with height? Relevance to normative ranges and circumferential indexes.
No full textBACKGROUND: Weight scales as height squared, which is an observation that forms the basis of body mass index (weight/height(2)). If, and how, circumferences, including waist circumference (WC) and hip circumference (HC), scale to height remains unclear, but this is an important consideration when developing normative ranges or applying WC/height and HC/height as risk indexes.OBJECTIVE: The study aim was to examine the scaling of weight, WC, and HC to height in NHANES (National Health and Nutrition Examination Survey) III participants.DESIGN: Subjects were adult non-Hispanic white, non-Hispanic black, and Mexican American men (n = 7422) and nonpregnant women (n = 7999) who had complete demographic and anthropometric data. In addition to height, allometric models were developed for each measure that controlled for age, race, and self-reported health status.RESULTS: After adjustment for age and race, weight scaled to height in men and women with mean (±SEE) powers of 2.29 ± 0.11 and 1.80 ± 0.07, respectively (both P < 0.001). Although univariate circumference-height models were weak or nonsignificant, when adjusted for age and race WC and HC scaled to height with powers of 0.76 ± 0.08 and 0.45 ± 0.05, respectively, in men and 0.80 ± 0.05 and 0.53 ± 0.04, respectively, in women (all P < 0.001). Age- and race-adjusted incremental increases in circumferences ranged from 0.2 to 0.5 cm per centimeter increase in height. Both WC/height and HC/height scaled negatively to height in men and women, and WC/HC scaled negatively to height in women only (all P < 0.001). Health status-adjusted models were similar.CONCLUSIONS: Circumferences and related ratios scale significantly to height, notably after adjustment for age and race, across subjects who are representative of the US population. These observations have implications for the clinical and epidemiologic use of these anthropometric measures and indexes
Percentage of body fat cutoffs by sex, age, and race-ethnicity in the US adult population from NHANES 1999-2004
No full textTo date, there is no consensus regarding adult cutoffs of percentage of body fat or estimated cutoffs on the basis of nationally representative samples with rigorous body-composition measurements.Background: To date, there is no consensus regarding adult cutoffs of percentage of body fat or estimated cutoffs on the basis of nationally representative samples with rigorous body-composition measurements. Objective: We developed cutoffs of percentage of body fat on the basis of the relation between dual-energy x-ray absorptiometry-measured fat mass and BMI (in kg/m(2)) stratified by sex, age, and race-ethnicity by using 1999-2004 NHANES data. Design: A simple regression (percentage of body fat = beta(0) + beta(1) x 1 divided by BMI) was fit for each combination of sex (men and women), 3 age groups (18-29, 30-49, and 50-84 y of age), and 3 race-ethnicity groups (non-Hispanic whites, non-Hispanic blacks, and Mexican Americans). Model fitting included a consideration of complex survey design and multiple imputations. Cutoffs of percentage of body fat were computed that corresponded to BMI cutoffs of 18.5, 25, 30, 35, and 40 on the basis of estimated prediction equations. Results: R-2 ranged from 0.54 to 0.72 for men (n = 6544) and 0.58 to 0.79 for women (n = 6362). In men, the percentage of body fat that corresponded to a BMI of 18.5, 25, 30, 35, and 40 across age and racial-ethnic groups ranged from 12.2% to 19.0%, 22.6% to 28.0%, 27.5% to 32.3%, 31.0% to 35.3%, and 33.6% to 37.6%, respectively; the corresponding ranges in women were from 24.6% to 32.3%, 35.0% to 40.2%, 39.9% to 44.1%, 43.4% to 47.1%, and 46.1% to 49.4%, respectively. The oldest age group had the highest cutoffs of percentage of body fat. Non-Hispanic blacks had the lowest cutoffs of percentage of body fat. Cutoffs of percentage of body fat were higher in women than in men. Conclusions: Cutoffs of percentage of body fat that correspond to the current US BMI cutoffs are a function of sex, age, and race-ethnicity. These factors should be taken into account when considering the appropriateness of levels of percentage of body fat
Association of lean tissue and fat mass with bone mineral content in children and adolescents
No full textThere has been uncertainty in the adult body composition literature about whether fat mass (FM) or fat free mass is a better predictor of bone mineral content and bone mineral density. This issue has recently also been raised in the pediatric literature. Based on suggested skeletal muscle-bone relationships, this study tested the hypothesis that in children and adolescents lean tissue mass (LTM) is a better predictor of total bone mineral content (TBMC) than is FM
Sarcopenia in Ageing and Chronic Illness: Trial Endpoints and Regulatory Issues
No full textABSTRACT In December 2024, the Society on Cachexia and Wasting Disorders (SCWD) hosted a Regulatory and Trial Update Workshop in Washington, D.C., bringing together experts from academia, industry, and the US Food and Drug Administration (FDA). This article summarizes key topics discussed during the meeting, including diagnostic challenges, emerging assessment methods, and trial endpoints. The D 3 ‐creatine dilution technique was highlighted as a promising tool for evaluating muscle mass. Additionally, the workshop addressed variability in computed tomography‐based lumbar skeletal muscle index measurements, emphasizing sources of variation at the instrument, imaging, and reader levels, as well as biological and clinical fluctuations. Discussions also focused on clinical trial endpoints for sarcopenia, particularly validated physical performance measures such as the Short Physical Performance Battery (SPPB), habitual gait speed, stair‐climb tests, and the 6‐min walk test. Furthermore, novel therapeutic approaches were explored, including 20‐hydroxyecdysone, enobosarm, anamorelin, ponsegromab, and nutritional supplementation, alongside broader strategies targeting myostatin‐activin signalling inhibition and Akt pathway activation. During the meeting, it was made clear that from a regulatory treatment development standpoint, clinically meaningful changes in patient‐reported outcomes, physical function and/or morbidity/mortality need to be shown. If the latter is not an efficacy endpoint, safety needs to be documented. Given that the population that may be addressed in aging associated sarcopenia is vast, the safety requirement standards applied for studies may be equivalent to those of studies in type 2 diabetes mellitus. Some argued at the meeting that this would make study programs so large that from an economic standpoint only therapies that significantly impact on morbidity/mortality outcomes have a chance to be considered commercially feasible for development
Identifying Athlete Body-Fluid Changes During a Competitive Season With Bioelectrical Impedance Vector Analysis
Full text linkPurpose: To analyze the association between body fluid changes evaluated by bioelectrical impedance vector analysis and dilution techniques over a competitive season in athletes. Methods: A total of 58 athletes of both sexes (men: age 18.7 [4.0] y and women: age 19.2 [6.0] y) engaging in different sports were evaluated at the beginning (pre) and 6 months after (post) the competitive season. Deuterium dilution and bromide dilution were used as the criterion methods to assess total body water (TBW) and extracellular water (ECW), respectively; intracellular water (ICW) was calculated as TBW–ECW. Bioelectrical resistance and reactance were obtained with a phase-sensitive 50-kHz bioelectrical impedance analysis device; bioelectrical impedance vector analysis was applied. Dual-energy X-ray absorptiometry was used to assess fat mass and fat-free mass. The athletes were empirically classified considering TBW change (pre–post, increase or decrease) according to sex. Results: Significant mean vector displacements in the postgroups were observed in both sexes. Specifically, reductions in vector length (Z/H) were associated with increases in TBW and ICW (r = −.718, P < .01; r = −.630, P < .01, respectively) and decreases in ECW:ICW ratio (r = .344, P < .05), even after adjusting for age, height, and sex. Phase-angle variations were positively associated with TBW and ICW (r = .458, P < .01; r = .564, P < .01, respectively) and negatively associated with ECW:ICW (r = −.436, P < .01). Phase angle significantly increased in all the postgroups except in women in whom TBW decreased. Conclusions: The results suggest that bioelectrical impedance vector analysis is a suitable method to obtain a qualitative indication of body fluid changes during a competitive season in athletes
Increased adiposity and impaired sleep are associated with severity of greater trochanteric pain syndrome: a cross-sectional study
No full textBackground: To investigate the feasibility and clinical validity of a digital anthropometric approach for body size and composition assessment in patients with greater trochanteric pain syndrome and to examine physical, sleep, and pain characteristics in different subgroups of patients. Methods: A convenience sample of 62 female patients was recruited. Administration of questionnaires, pain drawing analysis, evaluation of physical performance, body size and composition assessments were performed. Results: Pain intensity was significantly higher during evening (median value of 5) compared to both morning and afternoon (median values of 4). The median values of the Pittsburgh Sleep Quality Index (PSQI) global score and of sleep duration were 9.0 and 6.0 h, respectively. The median values of body fat percentage and fat mass index were 35.2% and 9.4 kg/m(2). Significant differences were observed between different subgroups of patients (low vs. high severity of tendinopathy-related disability) for the following variables: PSQI global score and proportion of patients with poor sleep quality (PSQI score > 5), body mass index, waist circumference, body roundness index, hip circumference, and fat mass index. Conclusion: Tendinopathic patients presented an impairment of sleep quality and quantity and an increased central adiposity that can be documented through clinimetric and body composition assessments
Obesity and functional impairment: influence of comorbidity, joint pain, and mental health
No full textTo examine the relationship between obesity and functional impairment and the influence of comorbidity, joint pain, and mental health on this association, we used US adult respondents (N = 430,912) to the 2007 Behavioral Risk Factor Surveillance Survey (BRFSS-07). Functional impairment was indicated if a respondent was either (i) limited in any way or in any activities because of physical, mental, or emotional problems, or (ii) had any health problem that required using special equipment such as a cane, wheelchair, special bed, or special telephone. Approximately 62.8% of respondents were overweight or obese and 20.3% were functionally impaired. The unadjusted relationship between obesity and functional impairment revealed a classical J-shaped pattern with odds ratios (95% confidence interval) compared to the normal weight group: 1.63 (1.54-1.73), 1.22 (1.20-1.25), 1.77 (1.73-1.81), 2.43 (2.36-2.51), and 4.12 (3.97-4.27) for underweight, overweight, obesity class I, II, and III, respectively. Although inclusion of different combinations of sociodemographic and medical covariates substantially attenuated the unadjusted association, the collective inclusion of all covariates in a single model did not eliminate the significant J-shaped association resulting in the following corresponding adjusted odds ratios: 1.19 (1.13-1.25), 1.01 (0.99-1.04), 1.23 (1.19-1.27), 1.38 (1.32-1.44), and 1.92 (1.82-2.02). The attenuation was mostly influenced by medical comorbidity. In conclusion, functional impairment is associated with obesity, primarily due to medical comorbidity conditions. The significant residual association highlights the importance of sustainable obesity prevention and treatment at both the individual and public level as functional impairment can create burdens at individual, familial, and societal levels
Weight/height2: Mathematical overview of the world's most widely used adiposity index
No full textA footnote in Adolphe Quetelet's classic 1835 Treatise on Man described his algebraic analysis of how body weight (W) varies with height (H) H ) in adult males and females. Using data on 12 short and 12 tall subjects of each sex, Quetelet established the rule that W is approximately proportional (/) to H-2 in adults; that is, W / H 2 when W approximate to alpha H-2 for some constant alpha . Quetelet's Rule (W W/H-2), transformed and renamed in the twentieth century to body mass index (BMI=W/H-2), is now a globally applied phenotypic descriptor of adiposity at the individual and population level. The journey from footnote to ubiquitous adiposity measure traveled through hundreds of scientific reports and many more lay publications. The recent introduction of highly effective pharmacologic weight loss treatments has heightened scrutiny of BMI's origins and appropriateness as a gateway marker for diagnosing and monitoring people with obesity. This contemporary context prompted the current report that delves into the biological and mathematical paradigms that underlie the simple index BMI=W/H-2 . Students and practitioners can improve or gain new insights into their understanding of BMI's historical origins and quantitative underpinning from the provided overview, facilitating informed use of BMI and related indices in research and clinical settings
Clinical Anthropometrics and Body Composition from 3-Dimensional Optical Imaging
No full textThe body size and composition assessment is commonly included in the routine management of healthy athletes as well as of different types of patients to personalize the training or rehabilitation strategy. The digital anthropometric analyses described in the following protocol can be performed with recently introduced systems. These new tools and approaches have the potential to be widely used in clinical settings because they are very simple to operate and enable the rapid collection of accurate and reproducible data. One system consists of a rotating platform with a weight measurement plate, three infrared cameras, and a tablet built into a tower, while the other system consists of a tablet mounted on a holder. After image capture, the software of both systems generates a de-identified three-dimensional humanoid avatar with associated anthropometric and body composition variables. The measurement procedures are simple: a subject can be tested in a few minutes and a comprehensive report (including the three-dimensional scan and body size, shape, and composition measurements) is automatically generated
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