BMI and Weight loss

Lose weight.  If you set New Year’s Resolutions, most likely that was one of them.  The most common resolution is to lose weight, and with adult and childhood obesity continuing to rise, it is incredibly important.  Knowledge is power and a first step to achieving your goals, so what is your body mass index (BMI)? Why should you know it, and why should you care?

BMI is a quick, objective measure of how fat you are.  It was developed in the 1800’s, renamed in the 1970’s and was designed as a tool to measure health in populations.  It is a quick way to assess and categorize large populations by taking height, divided by weight squared, and multiplying by a constant.  Your number falls into a category of underweight, normal, overweight, or obese.  BMI calculators can be easily found online. For the general population it is a fairly accurate measure.

Inaccurate for Athletes

For the very fit, athletic population it can place you in the overweight to obese category, because BMI does not take into account an increased proportion of muscle mass.  BMI may also underestimate body fat in older individuals who have lost a significant amount of muscle mass.  Muscle weighs more than fat and therefore if you are highly muscular BMI is not the best measure for you.

Body Fat Assessment Tools

The BMI is used internationally to categorize obesity by the World Health Organization. BMI, is the easiest way to determine body fat.  The gold standard to determine body fat is underwater weighing.  Underwater weighing is usually more expensive and less readily available. Other fairly accurate ways to determine body mass index are: skin fold calipers by a trained professional, skin impedance scales (must be done with appropriate levels of hydration) and circumference measurements.

BMI and Cardiac Risk Factors

According to the Centers for Disease Control and Prevention (CDC) as weight rises to the “overweight” and “obese” categories the risk for: Coronary artery disease, hypertension, type 2 diabetes, cancer, high cholesterol, stroke, sleep apnea, liver and gall bladder disease, osteoarthritis and fertility problems also increase.

Weight and Joint Health

Obviously, being a healthy weight is important for you, but it’s also important for your joints!  A study in the 2005 journal of Arthritis and Rheumatism found that for each pound of weight someone lost it reduced the forces going through their knee joint 4 fold!   Conversely, being just 10 lbs overweight increases the load in your knee with each step 30-60lbs!  That is just with walking, if you plan on jogging the force going through your knees is 2-3 times your body weight! If you have any knee problems or arthritis, or have had knee surgeries in the past just imagine the benefit of losing a few extra pounds.

Slow and Steady

Even 5 pounds may be enough to start you on a healthier path and take away a few aches and pains.  Weight loss should take time. You should not lose more than 2% of your body weight each week.  Your body weight can also fluctuate at least 5 pounds in a day.  Weigh yourself at a set time, once a week and be excited about small gains.  Small gains are more likely to last then dramatic initial weight loss. Seek out the wellness leadership U-District and involve others in your fitness and weight loss plans.  Remember, losing weight is not a fad, it is a lifestyle change.