How do we measure health? Is a number on the scale the most reliable way to determine how healthy we are? Scientists and exercise professionals say NO, and are taking steps to get the message out to everyone seeking the “crystal ball” of health.
Body Mass Index, BMI, has been used for almost 50 years both in the health care and fitness world, but it has limitations. BMI on its own as a measure of health is lacking due to its singular consideration of an individual’s total body weight. While it is important for an exercise practitioner to measure an individual’s body weight during an assessment, body weight merely provides the practitioner with a starting point for further information gathering. Weight and height measurements should not be the only measurements taken, and BMI is not the only indicator of weight-related health risks within an individual’s assessment. An incomplete assessment can jeopardize the individual’s subsequent management, care and exercise programming.
Health is More Than Numbers
Imagine if you will a 200 lb. man who stands 5 foot 8 inches tall. This man’s BMI outcome would be over 30, and he would be considered ‘obese’ on current BMI reference charts. Now imagine that this man is also an elite athlete, or a body-builder. Or, perhaps he is a long-time exerciser who regularly exceeds the accepted guidelines for regular physical activity. Is this man really to be considered “obese”? Should he be considered at risk for weight-related illnesses? And how do we exercise professionals discuss such outcomes with our clients?
Leading Canadian Research
In 2014, Dr. Veronica Jamnik and Dr. Norm Gledhill published Physical Activity and Lifestyle “R” Medicine, with health outcome and risk stratification charts to assist exercise professionals in this very area of client consultation. Such resources are used by all AFLCA Certified Fitness Trainers during their client assessments, discussions and consultations. This ensures that both professionals and the public they serve are receiving the most accurate and evidence-based guidance in their health and wellness goals.
The World Health Organization has also recognized the limitations of the use of BMI alone as a health indicator. As far back as 1995 the WHO adopted refinement (or enhancement) of BMI by adding Waist Circumference (WC) measurements. This scientifically supported protocol of combining BMI and WC helps to achieve a more accurate assessment of health status, and weight-related health risks. This evidence-based combination is also shared by the U.S. Centers for Disease Control (CDC) and National Institutes for Health (NIH), U.K. National Institute for Health and Care Excellence (NICE), CSEP, ACSM, AFLCA, Health Canada, Canadian Forces, and regionally, by Alberta Health Services.
Alberta Health Guidelines
In March of 2013, Alberta Health Services (AHS) released its Nutrition Guideline Body Measurements, applicable to: nurses, physicians and other health professionals that outline the following recommendations:
• Standard body measurements (should) include height, weight and waist circumference
• Measure the height and weight of adult and pediatric patients and clients
• Measure waist circumference of only adult patients and clients
• Use of estimated or self-reported data is not recommended
• BMI and waist circumference are used together to help estimate health risk
• Health risk should not be based on BMI and waist circumference alone, but should be components of a more complete health assessment
Why It Matters
This is an important notification for those working in the health and exercise field. We are “other health professionals” and should work in accordance to our guidelines for practice, which align with regional—in our case Alberta Health Services—professional recommendations.
Exercise professionals must work within their applicable Scopes of Practice (for example, in alignment with the scope of practice provided with your certification) at all times to protect our clients. Continuous professional development to remain educated and informed about new evidence-based research and changes in protocol within the field of exercise science is also a vital practice for all exercise professionals.
Why Use Numbers at All?
So why measure anything? Public health literature identifies excess abdominal fat as having higher health risks as compared to higher deposits of fat in the lower body regions, even in those with “normal” BMI ratings. BMI with WC can better predictor of risks of cardiovascular disease, type 2 diabetes, hypertension, gallstones, arthritis, and some forms of cancer, according to the CDC, NIH and Health Canada. A very extensive 2007 study of 168,000 primary care patients in 63 countries found that “importantly, [cardiovascular disease] CVD was significantly associated with [higher] WC even in lean individuals (BMI <25 kg/m2)” ( Balkau et al. ,p. 1945, 2007). The NIH and Public Health Agency of Canada (2011, p. 4) also recognize the limitations associated with BMI, as it is “not sensitive to level of fitness, maturational stage, sex, and race” (NIH, 2000, p. 21). Both agencies suggest measuring WC to clarify an individual’s health risks.
Accessible Tools for Safe Practice
The BMI with WC combination satisfies the need to have simple, accessible, and easy to understand tools for patient/client management, education and motivation. BMI calculations require only a scale and height measurement with either a calculator for full calculation, or reference chart to determine appropriate category. WC also requires minimal equipment—a flexible metric tape measure and reference chart are all a practitioner needs. A variety of other technology-based resources to measure an individual’s body fat percentage and primary fat deposit locations are available, but are limited in practical application due to cost and concerns over patient safety which detracts from patient care and treatment. Scientific research not only supports BMI with WC as evidence-based best practice tools, but also serves to promote the combination as an affordable, accessible option for use in a variety of private and public settings.
The effective care and treatment of those identified as overweight or obese must begin with accurate and accessible assessment. BMI with WC is such an assessment, and it is receiving global support. BMI with WC is quickly replacing the use of either assessment individually by all aligned healthcare professionals. Research has demonstrated that use of either assessment individually is inadequate, unreliable and specifically for BMI, irrelevant for today’s population. It is important for the general public to understand the uses and limitations of tools used to assess their health, and demand that their healthcare providers and exercise professionals use the most relevant, reliable, supported resources at every opportunity.
Knowledge is Power
Knowledge is power, and the more you know about how your health status ‘measures up’ the more effective your strategies to achieve good health can be.
Related Research, References and sources for this article
Current authorized ePARmed-x+ / PAR-Q+
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