Measuring Your Weight Loss Success

Once you start eating a more healthful diet and exercising, you should start losing weight fairly quickly. Here are a few tools you can use to track progress and gauge your effort as you work toward your weight loss goals.

• Body Mass Index
• Waist-to-Hip Ratio
• Target Heart Rate

Body Mass Index

The Body Mass Index (BMI) is a common tool for determining whether your weight is in the healthy range. BMI is a straightforward calculation based on your height and weight. Here’s the exact formula:

In pounds:

[Your Weight in Pounds ÷ (Your Height in Inches)²] x 703

In metric:

Your Weight in Kilograms ÷ (Height in Meters)²

This is what your BMI number will tell you:

• Underweight: BMI ≤ 18.5
• Normal weight: BMI = 18.5–24.9
• Overweight: BMI = 25–29.9
• Obese: BMI ≥ 30

While BMI is a convenient starting point for measuring and assessing your health relative to your weight, it isn’t enough on its own to give you a clear picture of your health risks. That’s because not all weight-to-height ratios reflect the same thing. For instance, a bodybuilder may weigh the same as his couch-potato brother, but they’ll obviously have different health risk profiles.

Recent research has shown that another measure—Waist to Hip Ratio (WHR)—is a much more accurate predictor of health risks.

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Waist-to-Hip Ratio

Various studies have shown a direct connection between the diameter of an individual’s waist and his or her risk of developing diabetes. Numerous other studies have found that visceral fat, also known as abdominal fat, is closely associated with diabetes, high blood-fat levels, and high blood pressure.

Based on this growing body of research about waist-to-hip ration (WHR), the general recommendation has been for everyone to not worry so much about losing weight but, instead, to concentrate on losing “waist.”

To find your own WHR, you need to measure very accurately. Here’s the simple division for this ratio:

Your waist circumference measured at your belly button ÷ Your hip circumference measured at the widest point

You can also find numerous online calculators to help you determine your WHR. World health officials say men have too much abdominal fat if their ratio is greater than 0.9. For women, the cutoff number is 0.85.

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Target Heart Rate

To get the most from your aerobic exercise efforts, you should try to keep your heart rate in the “target zone” while you’re exercising. Finding your target heart rate takes a few quick calculations. First you need to find your predicted maximum heart rate.

Predicted maximum heart rate. Your maximum heart rate (MHR) is the highest your pulse rate can get. For practical purposes, we calculate a predicted maximum heart rate. To do this, simply subtract your age from the number 220.

220 − Your Age = Predicted Maximum Heart Rate

Target heart rate. A normal target heart rate for aerobic exercise is between 60 to 80 percent of the predicted maximum heart rate. To calculate this range, multiply your predicted maximum heart rate by (.60) and then by (.80).

Predicted Maximum Heart Rate x (.60) = Low End of Target Heart Rate Range

Predicted Maximum Heart Rate x (.80) = High End of Target Heart Rate Range

You should never exercise above 85 percent of your maximum heart rate for an extended period of time, and if you have any health conditions, check with your doctor to see if your own exercise target heart rate should be lower than the standard range.

Exercise heart rate. To find your actual heart rate during exercise, stop your aerobic exercise and count your heartbeats. Do this by placing the tips of your index and second fingers on your neck below your jaw line, on either side of your windpipe. Press lightly until you can feel the blood pulsing under your fingers. Using a watch with a second hand, count the beats you feel for 30 seconds and then multiply this number by two.

Number of pulse beats in 30 seconds x 2 = Exercise Heart Rate

If your exercise heart rate is below your target zone, you can increase the intensity of your aerobic exercise. If it’s above your target zone, then you need to decrease your exercise intensity.