Overweight is often used interchangeably with pre-obese and is generally defined as having more body fat than is optimally healthy. Being overweight is a common condition, especially where food supplies are plentiful and lifestyles are sedentary. As much as 64% of the United States adult population is considered either overweight or obese, and this percentage has increased over the last four decades.
Excess weight has reached epidemic proportions globally, with more than 1 billion adults being either overweight or obese. Increases have been observed across all age groups.
A healthy body requires a minimum amount of fat for the proper functioning of the hormonal, reproductive, and immune systems, as thermal insulation, as shock absorption for sensitive areas, and as energy for future use. But the accumulation of too much storage fat can impair movement and flexibility, and can alter the appearance of the body.
Classification
The degree to which a person is overweight is generally described by Body Mass Index. Overweight is defined as a BMI of 25 or more, thus it includes pre-obesity defined as a BMI between 25 and 30 and obesity as defined by a BMI of 30 or more. Pre obese and overweight however are often used interchangably thus giving overweight a common definition of a BMI of between 25 -30. There are however several other common ways to measure the amount of adiposity or fat present in an individual's body.
- The Body Mass Index, or BMI is a measure of a person's weight taking into account their height. It is given by the formula: BMI equals a person's weight (mass) in kilograms divided by the square of the person's height in metres. Their units therefore are kg/m2 but BMI measures are typically used and written without units.
While the negative health outcomes associated with obesity are accepted within the medical community, the health implications of the overweight category are more controversial. The generally accepted view is that being overweight causes similar health problems as obesity just to a lesser degree. Adams et al. estimated that the risk of death increases by 20 to 40 percent among overweight people. and the Framingham Heart Study found that being overweight at age 40 reduced your life expectancy by three years.
Flegal et al., however, found that the mortality rate for individuals who are classified as overweight (BMI 25 to 30) may actually be lower than for those with an "ideal" weight (BMI 18.5 to 25).
Being overweight has been identified as a cause of cancer, and is projected to overtake smoking as the primary cause of cancer in developed countries as cases of cancer linked to smoking dwindle.
Psychological well-being is also at risk in the overweight individual. Discrimination against fat persons is common socially. This may affect their ability to find a mate or employment.
Overweight people are most likely to have lower self-esteem than others. This may make them seriously depressed and emotionally disrupted. They might attempt to seal themselves from the outside world. Teenagers, especially girls, are found to be extremely affected by overweightness. Children under the age of eight, however, are not emotionally affected by overweight problems.
