Your dietary habits significantly affect your body weight, body composition, and physical health. Recent studies show that over 60 percent of Americans are overweight or obese predisposing them to various diseases and degenerative problems. But what does overweight really mean? By public health standards being overweight is weight that is higher than what is considered as a healthy weight for a given height as determined by your Body Mass Index or BMI. Categories for BMI fall into the following:
Underweight = <18.5
Normal weight = 18.5–24.9
Overweight = 25–29.9
Obesity = BMI of 30 or greater
It is generally assumed that people in the overweight and obese BMI categories are at a higher risk of developing diabetes, cardiovascular disease, cancer, and a host of other degenerative problems. But, does BMI give the best indication of the health risk associated with your body weight? I think body composition is a much better indicator for associating body weight with health risks because it takes into account both muscle weight and fat weight.
Most health professionals now understand that building and maintaining muscle has many health benefits especially as you age and BMI does not take this into account. BMI is based only on body weight and it underestimates body fat as a result of the aging process. Most adults lose 5 to 7 lbs of muscle every decade of their lives after the age of 30 if they do not participate in a regular strength training program. Thus, someone who has gained 30 lbs between the ages of 30 and 60 has actually added more than 50 lbs of fat because they have lost 20 lbs of muscle during that same time period. This loss of muscle mass and the associated gain in body fat is a far greater indicator of long term health risk than just simply body weight..
Body composition measures take into account the ratio of muscle weight to fat weight. For example a 200 pound male with a body fat composition of 20 percent has approximately 40 lbs of fat weight and 160 of muscle weight. The ideal weight and fat to lean ratio varies considerable for men and women. The average healthy adult body fat range regardless of age is 15 to 20 percent for men and 20 to 25 percent for women. A male with more than 25 percent body fat and a woman with more than 32 percent body fat are both considered to be at risk for disease.
Another point in favor of body composition, is that people who exercise regularly, especially those who strength train tend to carry more muscle and weigh more relative to others of a similar height which means they have a higher BMI, and thus a false indication of a higher health risk. For example, I am 6’2″ and weight 227 lb which translates to a BMI measure of 29 which indicates that I am overweight and at risk for disease. However my body fat is at 12% which means that I am in excellent physical condition. So, again I ask, what does your body weight really tell you about your health.