Wednesday, January 2, 2013

Weight, What's in the Number?


As we ring in the new year, many of us find ourselves more mindful of the scale.

One downfall of most common scales is that we aren’t given a breakdown of body composition, meaning that they do not distinguish for us how much of the weight is from fat mass or non-fat mass.

Research demonstrates that body composition is directly related to health.  A normal balance of body fat to lean muscle is associated with good health and longevity, whereas altered body composition increases your risks for chronic disease, including cardiovascular disease and diabetes.  So, identifying an improper balance in body composition can allow for earlier intervention and prevention.  

You may wonder then, how do I determine my body composition?  There are a number of different ways to assess body composition.  The measure that I find works best clinically for determining body composition is bioelectrical impedance analysis (BIA).  A BIA machine uses the resistance of electrical flow through the body to determine the body composition. The electrical flow passes easily through non-fatty tissues which contain 70-75% water, and slower through fatty tissues which contain just 10-20% of water.  BIA analyzers are able to calculate a person’s body fat and fat-free mass using this impedance information, height and weight.

A BIA machine can also indicate hydration status and offer segmental readings of the body composition.  So, for example, you can see the ratio of body fat and fat-free mass in each of your arms, your legs and your trunk.  This is extremely helpful when monitoring weight loss as it illustrates if you are losing in the desired areas of the body.   

Other methods of determining body composition include skin fold testing, Air Displacement  Plethysomography/Bod Pod, underwater weighing, and DEXA.   

One of the most common methods used is by skin fold testing, however, it is a bit invasive as it requires areas of fat throughout the body to be pinched with calipers and is not very accurate.  Air Displacement Plethysmography, also known as the Bod Pod, is where body volume is measured through the displacement of air and body composition is determined through known equations.  Underwater weighing is based on similar principles, but is not readily accessible to most people or clinicians and has obvious dangers.  Dual energy x-ray absorptiometry (DEXA), determining body composition through radiography is the most accurate measure of body composition, however, this is reserved for clinical and research purposes and has the drawback of radiation exposure.

BIA readings are offered in our Ashburn office with the help of a fancy, computerized machine: the InBody 520.  This machine is used in research and offers highly precise (has a 98% correlation to the gold standard DEXA) and reproducible readings.

Readings are quick, easy and cost effective – they can be done in a 15 minute appointment and simply involve standing on the scale for 45 seconds while an imperceptible electrical current passes though the hands and feet.  After this process, we provide you with a report of the detailed measurements.  These reports offer useful indicators of health and hydration status, serve as a tracking tool for weight loss programs, and also help our integrative providers to create personalized dietary and exercise plans for patients.

Since BIA analyzers assume proper hydration, factors affecting hydration status can affect readings, it is best to get measured when you are well hydrated and at a similar time of day.  Other requirements for the most accurate reading can be found on our Web site.

If you’d like to learn more about our BIA machine and other fitness and nutrition services that we have to offer, save the date for Saturday, January 12th from 10 a.m. – 12 p.m. for a Free Wellness & Weight Loss Seminar.  This event is open to the public, but registration is required.  To register, call 703.554.1100 x 333 or email mschmidt@novamedgroup.com.

Whatever your personal wellness goals are for this new year, our team is here to support you and help you to succeed!  

-Posted by Sarah Giardenelli, ND, MSOM, LAc.