What does it mean to be under weight and over weight?

I thought a BMI of 25 was an accepted norm.
A bit of fat is acceptable. A friend of mine said he had a BMI of 2, and he looked just awful. I would consider that to be like living paycheck to paycheck on body health.

The body needs some fat to fuel itself when there is not fresh glycogen available. Also, at starvation levels, such as with severe anorexics, the body starts to cannibalize itself, so as to keep fuel getting to the brain. So a minimum body weight is needed for the body to have healthy functioning of all organs.

Conversely, being overweight puts a strain on every system in the body, especially the heart, liver, kidneys, pancreas. That in turn causes problems such as diabetes and high blood pressure.

Doctors have studied the issue for many years, and arrived at the BMI as a guide. Before that, insurance actuaries actually tied height and weight together to see what was the best range for the mortality tables.

Thank your life insurance company for working to gte the best guideline possible.

The numbers are arbitrary. The best scientific determination is the pinch test. Use your thumb and middle finger and pinch the area around your waist line.

I would guess they are based on statistics (the vast majority of people with weight-related health problems have a BMI greater than x, for instance). As such it is just a general rule and there are always exceptions to general rules. One can be very healthy with a BMI slightly outside of the accepted “healthy” range.

Body Mass Index is based on your age, weight and height. Because for every different age, there is a different fitness requirement. I can’t remember how to calculate BMI, but usually, BMI is only useful for determining whether you need to lose weight or not. It won’t be the least bit helpful health wise.

@filmfann, according to this article: http://health.howstuffworks.com/wellness/diet-fitness/weight-loss/bmi4.htm “In 1998, the National Institutes of Health lowered the overweight threshold for BMI 27.8 to 25 to match international guidelines.”

Underweight- poor nutrition is visible in poor skintone, hair quality, bad nails and stamina.

Overweight- rolls of skin, bloated face, neck, belly, bad feet, bad back.

I want to share something with you, @inunsure, that I didn’t know and just read. The BMI is a mathematical formula developed by a man by the name of Lambert Adolphe Jacques Quetelet who was born in 1796 in Flanders, Belgium. He was a mathematics instructor and a statistician, sociologist (much more than that if you read his biography below). He produced the formula to assist the government in allocating resources.

Here is a link to an older National Public Radio story that got me interested.

http://www.npr.org/templates/story/story.php?storyId=106268439

And this is a about his life:

http://www-history.mcs.st-andrews.ac.uk/Biographies/Quetelet.html

Also: http://www.encyclopedia.com/topic/Adolphe_Quetelet.aspx#2-1G2:2830903552-full

Each person is different. Your doctor is the best judge. Being either underweight or overweight affects your overall health. Your optimum weight is usually a 20 or 30 pound range, for me, 100 – 130 would be best.