Overweight, Obesity and BMI

Hasan A. Yahya, Ph.Ds

 Acoording to AHRO, over the past several decades, the prevalence of obesity among adults and children in the United States has increased dramatically and is reached epidemic proportions. Obesity in adults in the United States was 30.5 percent in 1999-2000. More than twice as many adults (nearly 65 percent) were considered to be either overweight or obese. Some 6 million U.S. adults were considered morbidly obese in 2001. Obesity is more common in  women, but men are more likely to be overweight. It is defined as having a body mass index (BMI, weight in kg/height in m2) of 30 or more. For example, a 5’5” woman weighing 180 pounds or more or a 5’11” man weighing 215 pounds or more would be termed obese. Morbid obesity is defined as having a BMI of 40 or more.

 Overweight is defined as having a BMI of 25 to 29.9 (a 5’5” woman who weighs 150 pounds or more or a 5’11”  man who weighs 180 pounds or more.

 Overweight and obesity are both labels for ranges of weight that are greater than what is generally considered healthy for a given height. Which identify ranges of weight that have been shown to increase the likelihood of health problems.

For assessing someone’s likelihood of developing overweight- or obesity-related diseases, the National Heart, Lung, and Blood Institute guidelines recommend looking for overweight predictors such as the Body Mass Index (BMI), the individual’s waist circumference, and other conditions associated with obesity such as high blood pressure or physical laziness.

The Body Mass Index (BMI) is just one indicator of potential health risks associated with being overweight or obese. For adults, overweight and obesity ranges are determined by using weight and height to calculate a number called the “body mass index” (BMI). BMI is for most people because it correlates with their amount of body fat. For example, an adult who has a BMI between 25 and 29.9 is considered overweight. While an adult who has a BMI of 30 or higher is considered obese. For example, a 5’ 9” height,  weight of 125 lbs to 168 lbs, with BMI between 18.5 and 24.9  BMI, are considered  healthy weight. From 169 to 202 lbs with BMI between 24 and 29.9 are overweight, and from 202 lbs plus, with 30 plus BMI, they are obese.

Other methods of estimating body fat and body fat distribution include measurements of skin-fold thickness and waist circumference, calculation of waist-to-hip circumference ratios, and techniques such as ultrasound, computed tomography, and magnetic resonance imaging (MRI).

In 2002, an estimated 15 percent of all children aged 6 to 19 years were overweight. For children and teens, BMI ranges above a normal weight have different labels (at risk of overweight and overweight). Additionally, BMI ranges for children and teens are defined so that they take into account normal differences in body fat between boys and girls and differences in body fat at various ages.

It is important to remember that although BMI correlates with the amount of body fat, BMI does not directly measure body fat. In the case of  athletes, they may have a high BMI which identify them as overweight even though they do not have excess body fat. (546 words) www.hasanyahya.com