Monday, May 14, 2012

Feature Article: Healthy Weight

When I meet a new weight loss client, one of the first questions I ask is, “How much weight would you ideally like to lose?”  Usually they turn around and ask me, “Well, how much do I need to lose?”   I figured that I’d create a post to help my readers answer this common question.

There are several guidelines to help you figure out your ideal weight.  As a Licensed Nutritionist and an Exercise Physiologist, my goal is to get my client down to a point where their weight will no longer increase their risk of chronic disease.  If they want to go a bit lower for cosmetic reasons, that is fine and I’m happy to help them do so.  However, when their weight is no longer going to negatively impact their health, I truly feel like I’ve done my job.  So how do you set your weight loss goals to minimize your risk of chronic disease?  There are actually 3 important measures.

Body Mass Index
Body mass index is a great place to start.  Your body mass index is your weight in kilograms divided by your height in meters squared.   If your body mass index is 25 or lower, your weight is considered normal.  If it falls between 25.1 and 29.9, you are considered overweight.  If it is 30 or more you are considered obese.

Risk of chronic disease begins to increase with BMI’s over 25 and rises sharply with BMI’s over 30.  I always have my clients shoot for a BMI under 25.  While the BMI measure isn’t perfect, there is a lot of solid research behind the numbers, so I always have my clients start there.  The Center for Disease Control has a free BMI calculator (click here).  You can use this calculator to figure out your BMI today and also what weight you need to reach to get it under 25.

Waist Circumference
The next area you want to focus on is your waist circumference.  Abdominal fat is particularly harmful to our health.  It has been associated with insulin resistance and inflammation, which can lead to increases in risk of heart disease, diabetes and even some cancers. 

Measure your waist with a tape measure right at your navel.  Men want to be below 40 inches and women want to be below 35 inches.  Your waist measure is important even if you are at a healthy weight.  Studies have shown that if your BMI is below 25 but your waist circumference is too high, your will have a significantly higher risk of death.

Body Fat
One other useful measure is your percent body fat.  The best way to measure this is with a DEXA scan.  This machine is often used to measure bone density.  Many don’t have access to one of these, so your next best bet is a bioelectrical impedance analyzer.

These machines work by shooting an imperceptible electric pulse up your body.  Since muscle and fat conduct electricity differently, your body fat can be measured.  If you are interested in picking up an analyzer, I recommend the brand Tanita.  Tanita sells a line of very accurate scales that come with a bioelectrical impedance analyzer.  They generally run around $100.  I’ve seen validation studies on these scales and when used correctly, they correlate highly with DEXA scans, which are the gold standard for body composition assessment.  Since bioelectrical impedance relies on proper levels of hydration, for 3 hours before the test you don’t want to eat, sleep, or exercise.

I’ve had a Tanita Ironman for years and love it.  To learn more about these analyzers or to pick one up, check out their website at tanita.com.

So what body fat should you shoot for?  A fit level of body fat is generally considered 14-17% for men and 21-24% for women.  That is a great goal to shoot for.


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