Posted June 1, 2016

The New Body Mass Index And Fitness Professionals

Recently the American Academy of Clinical Endocrinologists, a branch of which specializes in obesity management, came out with a series of guidelines on how to manage medical care for obese patients in the medical arena, and a lot of it can be utilized by fitness professionals working with their obese clients. One of the lead authors of the study and subsequent guidelines, Dr. Karl Nadolsky (brother of a former guest poster Dr. Spencer Nadolsky, and the two of them make up the Docs Who Lift website), agreed to offer some insights into how fitness professionals can use these guidelines and recommendations to help their clients more effectively.



The disease of obesity has become a well-known epidemic in our country and over the world with the accompanied complications leading to increased morbidity and mortality. I was recently involved with the authorship of new comprehensive guidelines for the evaluation and treatment of obesity from the American Association of Clinical Endocrinologists and was asked to summarize important points relevant to fitness professionals. This is crucial because, as we state in the guidelines, it is critical to involve all components of the health care forces in order to make progress in preventing and treating obesity.

Obviously, exercise is medicine, and we need fitness professionals to play an integral role alongside physicians, nurses, nutritionists, psychologists, and other allied health professionals (not to mention government, industry, health insurers, etc). I will try to highlight the salient points from the guidelines, including the premise of prevention, diagnosis, and treatment aspects I think will interest fitness professionals. Please read the available executive summary and the associated algorithm which are both available for free:



The guidelines actually start by answering a post-hoc question regarding the three phases of chronic disease prevention and treatment. Basically, since obesity is a complex and chronic disease, we must put efforts into primordial and primary prevention along with secondary and tertiary treatment. What this means for fitness professionals is that exercise and physical activity is a crucial component to the foundation of helping the population avoid the disease. Educational efforts should be inclusive of fitness professionals and they should lead in educating on the role of physical activity for prevention of developing obesity. I think an important point is that most people do not need complicated instruction but need to be encouraged and educated on the benefits of exercise and the vast array of exercise or physical activity that has been shown to help prevent obesity and its complications.



Certainly the diagnosis of obesity will be relegated to physicians or other nurse practitioners/physician assistants. Everyone involved, however, must understand what we are actually treating or preventing. The simple definition of obesity is, “excess adiposity.” As a lifetime athlete with an emphasis on strength training since I was a child, I have always been sensitive to the misinterpretation of using body mass index (BMI) to “diagnose” obesity or even in the research on obesity. We all know that lean/muscular athletes may have a BMI that is traditionally thought to be in the high range without actually having any increased adiposity or the health sequelae, in fact quite the opposite. We must acknowledge, however, that BMI actually does a very good job as a surrogate estimate of body fat in the general population and works well for population studies. But BMI also significantly underestimates adiposity and the health consequences in those with low muscle mass, including elderly patients, while measures of abdominal obesity (waist circumference) remain predictive of cardiometabolic disease and mortality (death). There are also ethnic differences due to genetic variation of the “sick fat.”

Thus, our first recommendation in the diagnosis is that BMI should be used just for screening and that a cut point of 25kg/m2 (23 for those of East/South Asian decent) to consider evaluating further for the diagnosis. The next point is key in understanding, and is also the most obvious but needs to be emphasized. The clinician must use the physical exam and clinical judgement when interpreting the BMI to decide if it actually represents increased adiposity! To help refine that, we suggest the use of waist circumference measurement for abdominal obesity.


If the patient has WC below suggested thresholds (94cm for men, 80cm for women, and 85cm/74-80cm for Asians resp) along with physical exam consistent with lean/muscular habitus, then there is no obesity. If the exam at that point is truly equivocal, then we recommend using more advanced measures of body fat percentage (air/water displacement plethysmography, dual-energy x-ray absorptiometry, bioelectric impedance, etc) but limitations must be acknowledged. Limitations include availability, cost, and lack of validation of the cut-points potentially familiar to the fitness community cited from the American College of Exercise or World Health Organization.

The next component of the diagnosis is very important to understand, and it involves the staging of the severity of obesity. It isn’t the amount of adiposity that we are ultimately concerned with, but the adverse health effects. I won’t belabor this detail too much, because it is up to the diagnosing clinician to use a checklist of obesity-related complications to stage the severity from 0-2. Stage 0 would be the patient who has excess adiposity (“overweight” classification if BMI 25-29.9 and “obesity” if BMI ≥ 30kg/m2) but is absolutely without symptoms due to that excess adiposity and has no basic biochemical criteria for adiposity-related disease.

Stage 1 obesity would include anyone who meets the exam criteria and suffers from mild complications (mild abnormalities of lipids/cholesterol, glucose/sugar, sleep apnea, arthritis, etc) while stage 2 encompasses more severe disease (type 2 diabetes, heart disease, male hypogonadism [low T], severe sleep apnea, etc). These stage help the clinician to decide on treatment intensity (secondary/tertiary). I think it is important for fitness professionals to have an awareness of this concept because it may help you understand the holistic treatment plan for different patients.

AACE ObesityAlgorithm 2016 <– Click here to download the entire algorythm

AACE Obesity CPG 2016  <– Click here to download the executive summary of the guidelines.


Here is where the rubber meets the road and is where we need to strive for multidisciplinary collaboration, with fitness professionals being critically important. As all medical guidelines do, we provide recommendations for physicians/clinicians to prescribe dietary intervention, physical activity intervention, and global behavioral intervention. We also go on to provide a very comprehensive individualized matrix of potential pharmaceutical considerations that having an awareness of could benefit fitness professionals.

Doctor holding a dumbbell

The dietary prescription guidance uses the body of evidence to encourage personalized nutrition plans. Our recommendations are consistent with The Obesity Society/American College of Cardiology/American Heart Association (TOS/ACC/AHA) which highlight the importance of energy deficit (caloric restriction) while improving the nutrient density. The evidence does not support one fad diet or macronutrient diet (except maybe higher protein) over another, though different dietary patterns may have some benefits and a table (9) of some of those is in the available executive summary.

Patient adherence is the most important aspect of the dietary component for treating obesity. For more detail, I encourage you to read the TOS/ACC/AHA dietary recommendations, await the full publication of our evidence base in July, or read the musings of our friend Alan Aragon who is well-known in the fitness/nutrition industry. But an understanding of the dietary plan is important for the fitness professional involved as it may improve exercise prescription.

Speaking of exercise prescription, please look at recommendation number 71 in our guidelines. As the lead author of the physical activity section, I took the opportunity to use my influence in hopefully making strides towards getting fitness professionals more involved with the medical team (a major priority for my younger brother Spencer, maybe you’ve heard of him?).

Since most major weight loss studies have utilized some sort of exercise specialist, we recommend involvement of an exercise physiologist or certified fitness professional to help individualize the physical activity prescription. This got a grade A recommendation folks! The other recommendations are unlikely to be news to this audience, and include aerobic & resistance training programs with progressive increasing of volume and intensity.


What I think this audience can garner from me, is understanding what our patient population is truly made of. These patients are often without any background in exercise and are starting with a blank slate and suffer from limitations and complications. Simple programs must be prescribed without experimenting with unnecessarily complex or even dangerous routines. Often, an initial walking program is most appropriate with the addition of simple compound upper body resistance training education. The key, again, is to personalize and individualize. #ExerciseIsMedicine



I hope this summary has at least sparked some interest and given some insight into our guidelines along with improved interpretation. We all have to be on the same page and continue making strides to function as an efficient health-care team. Keep up the great work you do and we (doctors) appreciate your contributions to the goals of patients.


Take-home points

  • Obesity is a chronic disease which requires a chronic care model of prevention and treatment
  • Obesity is a clinical diagnosis; not just a disease of size; it’s what’s on the inside that counts
  • Lifestyle is medicine: We need fitness professionals to collaborate with the medical professionals in order to optimize outcomes
  • Complications of obesity can be improved or ameliorated with > 5-15% weight loss
  • Obesity medications are not magic pills but can help adherence to lifestyle by combating the biology which is working against patients. Knowing your clients meds can help you understand the whole picture of treatment


Dr. Karl Nadolsky

Board Certified Endocrinologist

Diplomate, American Board of Obesity Medicine


Does a mean Ric Flair impression