By Susan Burke March, MS, RDN, LDN, CDE
Weight is just a number on the scale, but for most people, it can indicate a risk for diseases associated with obesity.
Most people have heard about that awkward equation that determines your Body Mass Index, or BMI. Some health experts have maintained that the BMI has its limits and that this ratio may not be the best predictor of health risk associated with your weight.
There is a more sensitive and comprehensive assessment test that can help you and your health care provider understand better how your weight may be impacting your health. And for that we owe a tip of the hat to our Canadian friends.
The experts who’ve weighed in on this important subject are declaring the Edmonton Obesity Staging System (EOSS) a more comprehensive and accurate way for clinicians and patients to talk about the risk for diseases associated with a patient’s weight.
The EOSS says that to assess a person’s health based on weight, the clinician will be better served using both Body Mass Index (BMI) and the Obesity Stage.
Obesity Class (1-3) is based on BMI, and is a measure of how “large” someone is compared to other people of the same height. (Obesity Class 1 = 30-34.9; Class 2 = 35 – 39.9; Class 3 = >40).
The Obesity Stage (0-4) is based on the medical, mental, and functional impact of obesity and is a measure of a person’s health as well as other factors that affect health and weight. It’s not based simply on a weight-height equation. A clinician will use the “4Ms” framework to assess mental, mechanical, metabolic and monetary obesity drivers.
Mental drivers include cognition, depression, eating disorders and more.
Mechanical obesity drivers include sleep apnea, arthritis, chronic pain, and more.
Metabolic issues include type 2 diabetes, hypertension and high cholesterol.
Monetary drivers of obesity, include employment, education and income – factors that may have a strong impact on the abilities of a person to lose and maintain weight loss.
It is now well established that EOSS is a far better predictor of obesity related mortality risk than BMI, or measuring weight alone. It also provides an important framework for both the patient and the clinician to target treatment.
So, you may be overweight, or worse, obese. You may not be sick, but you can be increasing your risk. Adopting lifestyle changes – not merely changes to your diet – but lowering stress, and being deliberately active (walking, climbing stairs, and taking part in more formal activities like working out or participating in fitness classes) can help lower your risk so you can enjoy a healthier, longer life.
Scaling back the BMI
The BMI is a ratio of weight to height, and represents an estimation of your body fat but it doesn’t measure body fat directly. Over time, it has come to be used to assess risk for diseases associated with weight. A number ranging between 18.5 and 25 translates to an optimal weight. Over 25 is considered overweight, while over 30 quantifies you as obese. A BMI below 18.5 is considered underweight and, for many, an abnormally low BMI can indicate health risk ranging from anorexia to hyperthyroid, or uncontrolled diabetes, digestive diseases, or even cancer.
The biggest criticism of BMI is that it may overestimate body fat in muscular people. My favorite example is former California governor, action hero actor and bodybuilder Arnold Schwarzenegger. Arnie stands about 6-foot-2 and 240 pounds. His BMI of 30.2 says that the Terminator is obese and therefore at risk of being terminated by his weight.
But a dire diagnosis based solely on his weight would be off base in a case like this.
I’d never call Arnie “fat”, or LeBron James – he measures 6’8” and weighs 249 pounds – BMI of 27.4.
It’s where you carry your weight that counts. If most of your fat is around your waist (abdominal obesity) rather than your hips you’re at increased risk for heart disease, type 2 diabetes, and all-cause mortality.
An article in the BostonGlobe.com cites research that shows that nearly 44% of adult American men and 65% of American women have abdominal obesity – stored fat around the abdomen means excess fatty acids leak into the liver causing inflammation and insulin resistance.
The optimal waist measurement for women is 35 inches or less; for men, it’s 40 inches or less but these numbers vary by race – for example, Asians are at higher risk than Caucasians at these measurements, so their maximums need to be minimized.
Check your waist size
Remember, BMI is just a screening tool – and weight is just a number on the scale – and is not the final indicator of your health or fitness. A better indicator of health risk is your waist to height ratio.
Not to be confused with your Waist/Hip Ratio (WHR), your WHtR calculates your body fat distribution and can be a significant early indicator of risk of diabetes, heart disease and stroke. Click here to calculate your WHtR.
The calculation is equally valid for children as it is for adults.
BMI is never used to assess pregnant women and for those over 65 years of age, the accepted standards of “normal” BMI of 18.5 – 25 may be too restrictive, and a slightly higher “normal” may be more protective from osteoporosis (thinning of the bones).
Do you have other important health issues which, if you have three or more, is called metabolic syndrome? They are: abdominal obesity, high blood pressure, high “bad” LDL cholesterol or low “good” HDL cholesterol, high triglycerides, and high blood glucose.
Take a measurement of your health, and make those small, simple changes that can pay off big time, and can lower your risk for diseases associated with being overweight. Read my column about enjoying your life while changing your lifestyle.
Susan Burke March, a Cuenca expat, is a Registered and Licensed Dietitian, a Certified Diabetes Educator who specializes in smart solutions for weight loss and diabetes-related weight management. She is the author of Making Weight Control Second Nature: Living Thin Naturally—a fun and informative book intended to liberate serial dieters and make healthy living and weight control both possible and instinctual over the long term. Do you have a food, nutrition or health question? Write to me at SusanTheDietitian@gmail.com