Losing Weight According to Your BMI

Fat caliper and measuring tape used to measure waistline, bodyfat levels for fitness and obesity check
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Are you worried that you may be overweight? First, talk to your doctor about your weight. He or she will be able to tell you whether or not you are actually overweight. Being overweight means your weight is higher than what is considered a normal weight for your height. In the past, height-weight charts were used to measure weight, but more reliable methods are favored now. Your doctor will want to assess how your weight is impacting your risk of developing weight-related health conditions.

Keep in mind, however, that being "overweight" by definition may not necessarily indicate a reason to lose weight. There is an approach to obesity called Health At Every Size (HAES) that encourages body acceptance and supports intuitive eating. Your healthcare provider can tell you if your weight is affecting your health and if weight loss is suggested.

There are three main ways weight-related risk is measured. They are:

If you are found to be at increased health risk with any of these assessment tools, you may be advised to lose weight to lower your health risks and improve your overall health.

Percent Body Fat

Percent body fat (PBF) can be assessed by measuring body composition (how much of your body is fat or non-fat) with a painless test called a caliper measurement. This test measures subcutaneous (under-the-skin) fat using a skin-fold caliper. The caliper is used to grasp a fold of skin and pull it away from your muscle. The folds are usually measured at the waist, hips, and thighs, and several other locations on the body. The findings are then calculated into a formula that allows your body fat to be estimated.

There are a few reasons why percent body fat measurement may not be ideal: The older you are, the less likely the results are to be accurate, since fat distribution changes as we age. Caliper measurement is best for those under the age of 55, though it can become less accurate by your 40s.

Additionally, the accuracy of the results can vary according to the skill of the person taking the measurements and the quality of the caliper used to take the measurement.

Lastly, the more overweight an individual is, the less accurate the results are likely to be.

Other methods of assessing body composition include bioelectrical impedance, DEXA scan, and BodPod tests.

What Does Your Percent Body Fat Mean?

Among others, the American Council on Exercise provides a Body Fat Categorization that is a scheme of acceptable body fat percentages. In theirs, average for women is between 25 and 31%, while a fitness percentage of body fat for women is between 21 and 24%. For men, average percentage body fat is 25 to 31% and a fitness percentage is 14 to 17%. Calculators for body fat percentage and more context regarding the subject, including several formulas for calculating body fat percentage using BMI, are available online, like this one from Calculator.net.

Recent cardiology research established that a high waist-to-hip ratio is a significant predictor of a major cardiovascular event in women but not men, while obesity calculated by BMI was not associated with major cardiac event in either men or women.

PBF assessment is not as widely used as other methods of assessing weight. The Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults suggest that since PBF is expensive to assess and equipment is not always readily available, BMI is a more practical approach than PBF.

The US Navy uses a very rigorous methodology for making a Body Composition Assessment that allows no substitute methods for measuring body fat, such as underwater weighing, skin-fold calipers, BMI, or even bio-electrical impedance. By directive of the Navy, all BCA measurements are to be conducted in the blue and gold Navy Physical Training Uniform (PTU) and are final. In 2017, the Navy introduced new BCA standards allowing body fat percentages to increase with age, permitting as much as 36% body fat in women over 40, and 26% in men the same age.

Waist-to-Hip Ratio

Waist-to-hip ratio (WHR) is calculated by taking your waist circumference and dividing it by your hip circumference.

You may sometimes hear body shapes referred to as "apples" and "pears." These two descriptors are related to WHR. Someone who is apple-shaped carries bulk around the midsection, while those who are pear-shaped carry the weight in the hip area.

To calculate your WHR, you will need a tape measure. You should measure your waist at its narrowest point and your hips at their widest point (see illustration). Then divide your results from your waist by the results of your hips. The resulting number is your waist-to-hip ratio.

WHR is used to assess risk for heart disease and hypertension in particular. Research has shown that waist-to-hip ratio is even better for determining the risk of heart problems than body mass index.

Those who are considered "apples" are at a much higher risk for heart disease and hypertension than "pears" who carry their weight in the hips or thighs. Research has shown that abdominal fat particularly raises health risks for women.

High cardiovascular risk for women is found with waist to hip ratios higher than 0.85, and 0.90 for men. As the ratio increases, so does the risk.

Body Mass Index

BMI can be determined by dividing your weight in pounds by your height in inches squared and then multiplying by 705.

For example, a woman who is 5'6" and weighs 190 would have a BMI of 31.

  • Height of 5'6" = 66 inches
    • 66 squared = 4,356
    • 190 divided by 4,356 = 0.0436
    • 0.0436 x 705 = 30.75 (which would be rounded up to a BMI of 31)

What Does Your BMI Mean?

The following applies to adults 20 years of age and older:

  • An individual is considered underweight if their BMI is less than 18.5.
  • A BMI of 18.5 to 24.9 is considered a "normal" weight.
  • A BMI of 25 to 29.9 is considered overweight.
  • In some instances, having a BMI between the range of 25-34.9 can increase the risk of developing certain conditions, such as diabetes, hyperlipidemia, and cardiovascular disease.
  • A BMI of 30 or more qualifies an individual as obese.
  • A BMI over 40 indicates that a person is morbidly obese.
  • Specifically, those who have a high BMI and a waist size of more than 40 inches for men, or 35 inches for women, have a higher risk for obesity-related health problems such as diabetes, high blood pressure, and heart disease.
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Article Sources
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  1. Penney TL, Kirk SF. The Health at Every Size paradigm and obesity: missing empirical evidence may help push the reframing obesity debate forwardAm J Public Health. 2015;105(5):e38-e42. doi:10.2105/AJPH.2015.302552

  2. Lee DH, Keum N, Hu FB, et al. Development and validation of anthropometric prediction equations for lean body mass, fat mass and percent fat in adults using the National Health and Nutrition Examination Survey (NHANES) 1999-2006. Br J Nutr. 2017;118(10):858-866. doi:10.1017/S0007114517002665

  3. Calculator.net. Body Fat Calculator. The Woodlands, Tex.: Calculator.net, Maple Tech International LLC 2008-2020 https://www.calculator.net/body-fat-calculator.html

  4. Medina-Inojosa JR, Batsis JA, Supervia M, et al. Relation of Waist-Hip Ratio to Long-Term Cardiovascular Events in Patients With Coronary Artery Disease. Am J Cardiol. 2018;121(8):903–909. doi:10.1016/j.amjcard.2017.12.038

  5. National Institutes of Health National Heart, Lung, and Blood Institute, North American Association for the Study of Obesity. The Practical Guide: Identification, Evaluation, and Treatment of Overweight and Obesity in Adults (.pdf). NIH Publication No. 00-4084. October 2000. Washington, DC: U.S. Department of Health and Human Services Public Health Service National Institutes of Health National Heart, Lung, and Blood Institute https://www.nhlbi.nih.gov/files/docs/guidelines/prctgd_c.pdf

  6. United States Navy. Navy Physical Readiness Program 2016. Guide 4. The Body Composition Assessment. (.pdf). https://www.public.navy.mil/bupers-npc/support/21st_Century_Sailor/physical/Documents/Guide%204-%20Body%20Composition%20Assessment%20(BCA)%202016.pdf

  7. NavyPRT.com. New Simplified BCA Chart. New body fat standards. September 9, 2017. NavyPRT.com https://www.navy-prt.com/new-simplified-bca-chart

  8. Ehrampoush E, Arasteh P, Homayounfar R, et al. New anthropometric indices or old ones: Which is the better predictor of body fat?. Diabetes Metab Syndr. 2017;11(4):257-263. doi:10.1016/j.dsx.2016.08.027

  9. World Health Organization. Waist Circumference and Waist–Hip Ratio: Report of a WHO Expert Consultation Geneva, 8–11 December 2008. Geneva: Department of Nutrition for Health and Development World Health Organization https://apps.who.int/iris/bitstream/handle/10665/44583/9789241501491_eng.pdf;jsessionid=4E36AD9E3E9E91302C75AEFB0FCBBEA0?sequence=1