Personalization of Nutrition Advice
David Heber, Zhaoping Li in Primary Care Nutrition, 2017
Using bioelectrical impedance analysis (BIA) is a practical and cost-effective way to assess body composition in the office (Kyle et al. 2004). BIA depends on the fact that muscle is about 70% water and conducts electricity, while fat is an insulator. The most commonly used machines are modified scales with four contact points. By placing two contact points on the hands and two on the feet and separating these by a wide distance, it is possible to pass an alternating microcurrent at 50 cycles/second (50 Hz) through the body and assess impedance. The computer in the machine using proprietary algorithms then estimates both lean body mass and fat mass. The lean body mass measurement is accurate, within 5–10%, while the body fat measurement is an estimate and does not specify the location of the fat, as was done with MRI.
Applied exercise physiology and health
Nick Draper, Helen Marshall in Exercise Physiology, 2014
Figure 14.2 provides an illustration of two instruments that are commonly used to assess body composition: skinfold calipers and a bioelectrical impedance analyser. Traditionally, exercise physiologists used skinfold calipers to measure a participant’s body fat percentage. Using this method, a fold of skin is measured between the calipers at a number of anatomical sites around the body. The skinfolds (measured in mm) at the selected sites are entered into a prediction equation to provide an estimation of body fat percentage. To ensure accuracy of results there must be a high degree of intratester (test-retest) and intertester (agreement between all testers) reliability. Bioelectrical impedance analysis (BIA) is increasingly being used by physiologists as a faster, and often equally accurate, method for assessing body composition. This method involves a participant standing still on the analyser with bare feet and, in some analyser models, holding two handholds with arms not touching the body. An undetectable, low level electrical current is passed through the body. rior to standing on the analyser, the participant should empty their pockets and remove any jewellery, to avoid disturbance of the electrical current. Body water is high in electrolytes and so is an excellent electrical conductor. Lean body mass has a relatively high water content compared to fat mass and, as a consequence, the differences in impedance to conductivity can be used to assess body fat percentage. Bioelectrical impedance analysers provide an estimate (using prediction equations based on bioelectrical impedance results) of total fat mass, lean body mass and often the fat mass for each limb and the trunk. As the calculation of the results is based on body water content and the resultant electrical conductivity, the hydration status of an individual will directly affect the results. When a participant last ate, drank or exercised before a test will impact on the results and therefore needs to be controlled to maintain the integrity of the analysis.
The Effects of Zinc and Selenium Supplementation on Body Composition and Thyroid Function in Individuals with Overweight or Obesity: A Systematic Review
Published in Journal of Dietary Supplements, 2023
Antonis Zavros, Christoforos D. Giannaki, George Aphamis, Zoe Roupa, Eleni Andreou
Types of participants: Overweight or obese human individuals (BMI ≥25 kg/m2).Types of studies: Randomized controlled trials.Types of interventions: Any dose of Zn, Se supplementation or their combination. Studies where Se or Zn supplementation were combined with other micronutrients were excluded.Types of outcome measures: Body composition measurements and thyroid function (TSH, FT3, FT4). For the purpose of this review, body composition assessment methods were separated to direct (densitometry, computed X-ray tomography, magnetic resonance imaging, and dual-energy X-ray absorptiometry) and indirect (anthropometry and bioelectrical impedance analysis) (67). Although both direct and indirect measurements have their limitations (68), indirect methods generally have higher predictive errors than direct methods (67, 69). Categorizing body composition measurements as direct and indirect has been previously used in another systematic review (44). The main difference of the present systematic review is that bioelectrical impedance analysis (BIA) was considered an indirect method.Results were limited to studies published in journals in English, while book chapters, review papers, and animal studies were excluded.
Association of body composition with menopausal symptoms in (peri-)menopausal women
Published in Climacteric, 2018
Y. Zhou, Y. Zheng, C. Li, J. Hu, Y. Zhou, L. Geng, M. Tao
Body mass index (BMI) is an overall summary measure of body size, but does not always demonstrate adequate sensitivity and specificity5. The accurate assessment of fat mass is of prominent importance for obesity, while body composition may be a more precise tool compared to BMI due to the fact that there might be minor changes in body weight but still important changes in body composition6. Compared with dual-energy X-ray absorptiometry and computed tomography, bioelectrical impedance analysis (BIA) is more applicable to clinical routine as a measurement for body composition due to its easy methodology, safety and non-invasive, inexpensive features6,7. Moreover, a study has confirmed the validity and predictive value of BIA for menopausal women8.
The decrease in phase angle measured by bioelectrical impedance analysis reflects the increased locomotive syndrome risk in community-dwelling people: The Yakumo study
Published in Modern Rheumatology, 2019
Satoshi Tanaka, Kei Ando, Kazuyoshi Kobayashi, Tetsuro Hida, Taisuke Seki, Takashi Hamada, Kenyu Ito, Mikito Tsushima, Masayoshi Morozumi, Masaaki Machino, Kyotaro Ota, Naoki Ishiguro, Yukiharu Hasegawa, Shiro Imagama
For over 25 years, bioelectrical impedance analysis (BIA) has been used for the estimation of body composition. BIA is an easy-to-use, inexpensive, and non-invasive method that can be repeated frequently. It is used as a component of clinical health checkups. Among the variables measured with BIA, muscle mass has been reported as related to LS [12,13], and phase angle is considered as one of the clinically important impedance parameters. Phase angle has gained popularity in recent years as it has been shown to be highly predictive of impaired clinical outcomes and mortality in a variety of diseases [14,15]. Furthermore, it is reported that phase angle obtained via BIA is positively correlated with muscle mass [16]. With the above in mind, the aim of this study was to investigate whether muscle mass and phase angle assessed by BIA are related to LS risk stage and whether they can be useful screening tools for LS risk in a large-scale prospective health checkup setting in middle-aged and elderly people.
Related Knowledge Centers
- Body Composition
- Body Fat Percentage
- Body Water
- Dehydration
- Dielectric Spectroscopy
- Muscle
- Resting Metabolic Rate
- Adipose Tissue
- Dual-Energy X-Ray Absorptiometry
- Magnetic Resonance Imaging