Creative Assessments: Why Weight and BMI Aren’t Always a Good Fit

 

By CARRIE MYERS

Becoming ACE certified demonstrates your proficiency in the science of exercise and personal training, while putting your knowledge into practice helps you develop and hone the art of training, which is what makes training personal. It’s what adds that individualized touch to each client and allows you, as the professional, to get creative with your assessment strategies and workout methods. It’s also what makes many trainers uncomfortable, because it may not involve traditional methods of evaluating clients’ progress.

Entering the field, we’re taught about several assessment methods, including weight, body mass index (BMI), body composition, and circumference measurements. While we know body weight doesn’t tell the whole story, it tends to be the most frequently used method due to its simplicity and ease.

“Scales measure overall weight,” says Peter Pellerito, M.S., fitness specialist at the University of Nebraska Medical Center’s Center for Healthy Living. “They do not differentiate between fat and lean body weight. Your scale weight also varies independent of any changes in fat and muscle.”

Pellerito continues: “Food in, waste out, hydration, glycogen stores, and fluid retention all create fluctuations in scale weight independent of changes in fat and muscle. If you drink 16 ounces of water, you gain a pound on the scale, but your fat weight remains unchanged.”

And body mass index? “BMI has shown many advantages as a surrogate of [body fat testing],” explain the authors of a recent Mayo Clinic study, “such as simplicity and reproducibility; and epidemiologic studies have shown an association between extreme values of BMI and increased mortality. However, a significant limitation of using BMI is its failure to differentiate between an elevated body fat content and preserved or increased lean mass, especially in [people] with a BMI of less than 30 kg/m.”

In other words, someone can be within a normal weight or BMI range, but have too much body fat on their frame. This concept is so prevalent that researchers at the Mayo Clinic coined the term “normal-weight obesity,” defined as the combination of normal BMI and high body-fat content. They estimate that approximately 30 million Americans are normal-weight obese. That means more than half of the American population that is considered to be at an average weight is actually over-fat. Furthermore, researchers found that normal-weight obesity is associated with a higher prevalence of cardiometabolic dysregulation*, metabolic syndrome and cardiovascular risk factors, including a higher mortality rate when compared to a lower body-fat group.

*After controlling for age, sex and race, normal-weight obesity subjects had significantly higher rates of several alterations in blood chemistry that can negatively affect heart and metabolic health. These markers of dysregulation include: altered blood lipid profile, such as elevated cholesterol; high leptin, a hormone found in fat and other tissues that is involved in appetite regulation; and higher rates of metabolic syndrome.

Why Get Creative With Assessments?

The Mayo Clinic study and similar findings are encouraging practitioners to use other methods of assessment for clients and patients. While body-composition testing is certainly an option, it can be time-consuming and, in some cases, inaccurate.

“There is no way to directly measure body composition,” explains Pellerito, “unless you decompose the individual. All systems of estimation involve significant potential for error.”

If body composition methods are used, Pellerito suggests that you fully disclose to your client the limitations of the processes. Skin-fold measurements, for instance, are dependent on the tester’s proficiency in this skill. “And bioelectrical-impedance methods can be notoriously inaccurate,” he adds.

The Mayo Clinic study authors suggest simply measuring waist circumference, because it is the excess abdominal adiposity that places people at greater disease and mortality risk.

“For the purposes of self-comparison over time,” adds Pellerito, “waist circumference is also useful. It is unlikely that your waist measurement will increase regardless of how much muscle you might gain. It’s also easy for the trainer or individual to do this measurement.”

Meshing Science and Art to More Effectively Assess Clients

Data collection helps us, as trainers, to determine if the methods we’re using with our clients are working. But are they always helpful and motivating to our clients? Veronica Roselle, a blogger for ilovequitters.com and a former ACE-certified personal trainer doesn’t think so. You see, at one time, Roselle was also 359 pounds, bulimic and a compulsive overeater.

“The number on the scale often determines my self-worth,” she says. “We are a society of numbers—how much people make, how much they weigh, how many material things they have. [When I was heavy] I found I was always waiting to start my life based on what I weighed. It was very self-defeating.”

Today, Roselle is a size 4–6, but can’t really tell you how much she weighs. “I don’t own a scale and only weigh myself at the doctor’s office.”

“Here’s the thing,” she continues, “I will never be happy with the number on the scale. The scale is lethal. If I weigh more than I think I should, I want to binge, because I feel like a failure. If I weigh less than I thought it also gives me permission to eat, because I have a little wiggle room. Either way I lose. For today, I try to live with dignity and integrity in all I do and do not let the scale determine my self-worth.”

And research suggests that even women without a history of eating disorders can be profoundly affected by the number on the scale.

A recent Brigham Young University study showed that women’s brains in general may be hard-wired to worry about weight. For the study, normal-weight men and women, ages 18 to 30, viewed images of people of their own gender with various body shapes. As the subjects viewed each image and their brains were scanned using functional MRI, they were told to “imagine someone is saying, ‘Your body looks like his/hers.’”

The brain scans of the women who saw images of overweight individuals displayed a rise in activity in an area of the brain believed to be linked to self-reflection and the assessment of self-worth. When women pictured themselves as slender, they did not have the same rise in brain activity.

Interestingly, the men in the study showed no change in brain activity whether they imagined themselves thin or fat.

Dr. Mark Allen, a neuroscientist and one of the study’s authors, told the NY Daily Mail, “These women have no history of eating disorders and project an attitude that they don’t care about body image. Yet under the surface is an anxiety about getting fat.”

“Many women learn that bodily appearance and thinness constitute what is important about them, and their brain response reflects that,” adds Diane Spangler, a psychologist and Allen’s fellow researcher. “I think it is an unfortunate and false idea and does put one at greater risk for eating and mood disorders.”

Creating an Assessment "Menu"

All of which brings up an important question: Are we, as fitness professionals, perpetuating this idea by pushing certain tests on our clients? If women, especially, are prone to negative perceptions about their body image and weight (whether or not they admit to those negative perceptions), are we ultimately setting them up for failure in the long run? Should we instead offer them the opportunity to choose their own assessment methods from a “menu” of options?

Adam Reid, co-owner of Back2Health: Total Fitness in Hanover, Mass., takes a more traditional approach to assessments. While he does use a variety of methods to assess his clients, including weight, body composition and waist circumference, he doesn’t leave the choice up to them. “If [my clients] are serious about changing appearance, they usually understand the need for such a wide variety of measurements and appreciate the effort that goes into collecting and then interpreting the data.”

And if a client is uncomfortable with a test? “If unhappy at first to have a tape measure around their midsection, it usually only adds to the incentive to make a change for the better,” explains Reid. “In other words, their discomfort can be used as reinforcement to make the necessary alterations to their current diet/exercise strategy in order to achieve a goal.”

Not always, argues Roselle. “When I had a BMI over 30 I knew I was in big trouble, but I really didn’t need my body fat or BMI calculated to tell me that.”

“Weight management is important, but the scale or body composition should not be the only or the ultimate measure of accomplishment,” agrees Pellerito. “A continued commitment to leading a healthy lifestyle is the most important criteria. In assisting those struggling to build the habit of regular physical activity participation, I would focus only on providing information that enhances client confidence, motivation and a sense of self-worth. Weight and body composition are not the only available objective measures.”

Pellerito suggests including clinical indicators like glucose tolerance, blood pressure and lipid levels, which can be improved with even modest weight loss of less than 10 percent of total body weight. “The broader perspective of having a better life and not just better body composition should be the goal promoted by the trainer. Unfortunately, dieting can lead to ultimate weight gain, decreased self-esteem and increased risk for disordered eating instead of good health and happiness.”

Ryan Halvorson, associate editor for IDEA Health & Fitness Association and a personal trainer at the Wave House Athletic Club in San Diego, Calif., likes to perform the same assessments on each client to help keep the process streamlined. But, he says, he eliminates one or more of them if a client is resistant.

“Many are flexible and open to alternate methods such as using ribbon and mood journals (see sidebar),” he says. “Others insist on using traditional methods that place a focus on numbers. If I feel that the focus transitions to an obsession that negatively affects progress, then I urge the client to try it my way for a while.”

Halvorson explains that when he first meets with a client, they work together to determine what's most important to them. “For instance, a recent client is interested in becoming a better swimmer and so we set goals based on the laps she swims. This goal is also an assessment tool. If she's not achieving reasonable goals then something needs to be changed. Each client is different and I allow them to determine which assessments will help them be most successful. This is where the creativity comes into personal training.

For some, however, traditional assessment methods will never be a good “fit.”

“My “scale” today is how my clothes fit, how my bra and panties fit, how my rings and necklaces fit,” says Roselle. “That is my scale. As a society we get too consumed with the number on the scale. End of story.”

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Carrie Myers has a bachelor’s degree in exercise science and has been a freelance writer for more than 11 years. She is the author of the award-winning book, Squeezing Your Size 14 Self into a Size 6 World: A Real Woman's Guide to Food, Fitness, and Self-Acceptance and presents, teaches and trains in N.H. and Vt.