Publications by authors named "Nisa N Kelly"

Background & Aims: Body shape expressed as the trunk-to-leg volume ratio is associated with diabetes and mortality due to the associations between higher adiposity and lower lean mass with Metabolic Syndrome (MetS) risk. Reduced appendicular muscle mass is associated with malnutrition risk and age-related frailty, and is a risk factor for poor treatment outcomes related to MetS and other clinical conditions (e.g.

View Article and Find Full Text PDF
Article Synopsis
  • Bioelectrical impedance analysis (BIA) is increasingly used for body composition estimation in both clinical and field settings, but device variations and equations can lead to inconsistent results.
  • This study evaluated raw resistance and reactance measurements from three different BIA devices to identify inter-device variation and its effect on body composition predictions among athletes.
  • Results showed significant differences in impedance measurements and body composition estimates across devices, with variations as large as 8.8 kg, underlining the importance of using population-specific equations for accurate assessments.
View Article and Find Full Text PDF

Individuals in isolated and extreme environments can experience debilitating side-effects including significant decreases in fat-free mass (FFM) from disuse and inadequate nutrition. The objective of this study was to determine the strengths and weaknesses of three-dimensional optical (3DO) imaging for monitoring body composition in either simulated or actual remote environments. Thirty healthy adults (ASTRO, male = 15) and twenty-two Antarctic Expeditioners (ABCS, male = 18) were assessed for body composition.

View Article and Find Full Text PDF

Background: Body shape, an intuitive health indicator, is deterministically driven by body composition. We developed and validated a deep learning model that generates accurate dual-energy X-ray absorptiometry (DXA) scans from three-dimensional optical body scans (3DO), enabling compositional analysis of the whole body and specified subregions. Previous works on generative medical imaging models lack quantitative validation and only report quality metrics.

View Article and Find Full Text PDF
Article Synopsis
  • Researchers created a new way to measure body composition (like fat and muscle) using special technology and methods to make it easier and more accurate.
  • They tested this new model on a group of adults and found that it worked well, showing similar results to the older, more complicated methods.
  • The new method was also tested again with a different group and confirmed to be reliable, meaning it can help people keep track of changes in their body composition over time.
View Article and Find Full Text PDF
Article Synopsis
  • Athletes can have different levels of hydration which can make it hard to measure their body composition accurately and track their strength progress.
  • The Da Kine Study tested different methods to measure body composition in athletes, including underwater-weighing and X-ray scans, to see which worked best despite hydration differences.
  • The study found that some methods like air-displacement and X-ray were quite accurate in measuring body fat and muscle mass, and stronger athletes tended to have higher muscle mass according to these measurements.
View Article and Find Full Text PDF

Background: New recommendations for the assessment of malnutrition and sarcopenia include body composition, specifically reduced muscle mass. Three-dimensional optical imaging (3DO) is a validated, accessible, and affordable alternative to dual X-ray absorptiometry (DXA).

Objective: Identify strengths and weaknesses of 3DO for identification of malnutrition in participants with low body mass index (BMI) and eating disorders.

View Article and Find Full Text PDF

Background: Excess adiposity in children is strongly correlated with obesity-related metabolic disease in adulthood, including diabetes, cardiovascular disease, and 13 types of cancer. Despite the many long-term health risks of childhood obesity, body mass index (BMI) Z-score is typically the only adiposity marker used in pediatric studies and clinical applications. The effects of regional adiposity are not captured in a single scalar measurement, and their effects on short- and long-term metabolic health are largely unknown.

View Article and Find Full Text PDF

Background: The obesity epidemic brought a need for accessible methods to monitor body composition, as excess adiposity has been associated with cardiovascular disease, metabolic disorders, and some cancers. Recent 3-dimensional optical (3DO) imaging advancements have provided opportunities for assessing body composition. However, the accuracy and precision of an overall 3DO body composition model in specific subgroups are unknown.

View Article and Find Full Text PDF

Background: Recent 3-dimensional optical (3DO) imaging advancements have provided more accessible, affordable, and self-operating opportunities for assessing body composition. 3DO is accurate and precise in clinical measures made by DXA. However, the sensitivity for monitoring body composition change over time with 3DO body shape imaging is unknown.

View Article and Find Full Text PDF
Article Synopsis
  • This study evaluated if three-dimensional optical (3DO) scanning of body shape and composition could better predict metabolic syndrome (MetS) compared to just using Body Mass Index (BMI) and demographic factors.
  • A diverse group of 501 adults participated, with 87 diagnosed with MetS, and various predictive models were tested using logistic regression.
  • The results showed that incorporating 3DO data significantly improved prediction accuracy for MetS, increasing risk classification by 29% compared to BMI alone.
View Article and Find Full Text PDF

Background: Novel advancements in wearable technologies include continuous measurement of body composition via smart watches. The accuracy and stability of these devices are unknown.

Objectives: This study evaluated smart watches with integrated bioelectrical impedance analysis (BIA) sensors for their ability to measure and monitor changes in body composition.

View Article and Find Full Text PDF

Background: Many predictors of morbidity caused by metabolic disease are associated with body shape. 3D optical (3DO) scanning captures body shape and has been shown to accurately and precisely predict body composition variables associated with mortality risk. 3DO is safer, less expensive, and more accessible than criterion body composition assessment methods such as dual-energy X-ray absorptiometry (DXA).

View Article and Find Full Text PDF

Background: The accurate assessment of total body and regional body circumferences, volumes, and compositions are critical to monitor physical activity and dietary interventions, as well as accurate disease classifications including obesity, metabolic syndrome, sarcopenia, and lymphedema. We assessed body composition and anthropometry estimates provided by a commercial 3-dimensional optical (3DO) imaging system compared to criterion measures.

Methods: Participants of the Shape Up! Adults study were recruited for similar sized stratifications by sex, age (18-40, 40-60, >60 years), BMI (under, normal, overweight, obese), and across five ethnicities (non-Hispanic [NH] Black, NH White, Hispanic, Asian, Native Hawaiian/Pacific Islander).

View Article and Find Full Text PDF

Objective: The aim of this study was to investigate whether digitally re-posing three-dimensional optical (3DO) whole-body scans to a standardized pose would improve body composition accuracy and precision regardless of the initial pose.

Methods: Healthy adults (n = 540), stratified by sex, BMI, and age, completed whole-body 3DO and dual-energy X-ray absorptiometry (DXA) scans in the Shape Up! Adults study. The 3DO mesh vertices were represented with standardized templates and a low-dimensional space by principal component analysis (stratified by sex).

View Article and Find Full Text PDF

Objective: This study aimed to explore the accuracy and precision of three-dimensional optical (3DO) whole-body scanning for automated anthropometry and estimating total and regional body composition.

Methods: Healthy children and adolescents (n = 181, ages 5-17 years) were recruited for the Shape Up! Kids study. Each participant underwent whole-body dual-energy x-ray absorptiometry and 3DO scans; multisite conventional tape measurements served as the anthropometric criterion measure.

View Article and Find Full Text PDF