Am I overweight?
As noted, over 50% of people are. The definition of overweight is derived by looking at studies showing the relationship of weight to the occurrence of death or medical problems. In this analysis, "overweight" is not a subjective decision. It is present when a health problem is shown to occur at a given level of weight. It is important to note however that one need not attain "ideal body weight" to achieve successful weight loss. Losing some weight confers definite health advantages to many and may be a success!
Desirable weight depends on a person's height. A useful tool which corrects for a person's height is the "Body Mass Index", or "BMI".
* BMI = (Weight in kilograms) / (Height in meters squared).
* The non-metric formula is BMI = [(weight in pounds) / (height in inches squared)] x 703.
The classification of overweight and obesity according to the BMI (which is expressed as kg/m-2) is:
* "Underweight": less than 18.5
* "Normal": 18.5 - 24.9
* "Overweight": 25 - 29.9
* "Obese": > 30
* "Extreme" or "Morbid" obesity: > 40
Other measurements of importance are waist circumference and waist:hip ratio. Males with waist circumference of greater than 40 inches or women with greater than 35 inches are at risk. Men tend to carry their extra pounds in the abdominal area, and women in their hip areas. The male pattern of obesity (which can be visualized as an "apple") is a higher risk than the female pattern (visualized as a "pear"). For the same waist circumference, the amount of weight carried within the abdominal cavity is more important in determining risk than the amount of fat under the skin but outside of the cavity. This latter determination requires sophisticated testing not generally done in clinical settings. Men have a higher waist:hip ratio, and a higher risk of complications of obesity.
Another concept worth considering is "percent body fat", which is similar to "lean body weight". These can be derived from standard equations, or made more specific by measuring the thickness of the skin at specific locations (they don't cut the skin and measure it . . . the skin can be folded and measured with calipers!).
The risk of being overweight is less in adults over 65 years of age. Indeed, being too skinny is an important risk in many elderly people. Under nutrition is not to be ignored.
