Overweight

Description, causes, prevention, treatment and medicinesObesity

Overweight is having more body fat than is optimally healthy. Being overweight is common especially where food supplies are plentiful and lifestyles are sedentary.

Excess weight has reached epidemic proportions globally, with more than 1 billion adults being either overweight or obese in 2003. In 2013 this increased to more than 2 billion. Increases have been observed across all age groups.

A healthy body requires a minimum amount of fat for 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, flexibility, and alter appearance of the body.

Classification

The degree to which a person is overweight is generally described by body mass index (BMI). 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 interchangeably 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.

Body mass index
The body mass index (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. The units therefore are kg/m2 but BMI measures are typically used and written without units.

Body volume index
The body volume index (BVI) was devised in 2000 as a computer, rather than manual, measurement of the human body for obesity and an alternative to the BMI
Body volume index uses 3D software to create an accurate 3D image of a person so BVI can differentiate between people with the same BMI rating, but who have a different shape and different weight distribution.

Simple weighing
The person's weight is measured and compared to an estimated ideal weight. This is the easiest and most common method, but by far the least accurate, as it only measures one quantity (weight) and often does not take into account many factors such as height, body type, and relative amount of muscle mass.

Skinfold calipers or "pinch test"
The skin at several specific points on the body is pinched and the thickness of the resulting fold is measured. This measures the thickness of the layers of fat located under the skin, from which a general measurement of total amount of fat in the body is calculated.

Bioelectrical impedance analysis
A small electric current is passed through the body to measure its electrical resistance. As fat and muscle conduct electricity differently, this method can provide a direct measurement of the body fat percentage, in relation to muscle mass.

Hydrostatic weighing
Considered one of the more accurate methods of measuring body fat, this technique involves complete submersion of a person in water, with special equipment to measure the person's weight while submerged. This weight is then compared with "dry weight" as recorded outside the water to determine overall body density. As fat is less dense than muscle, careful application of this technique can provide a reasonably close estimate of fat content in the body.

Dual-energy X-ray absorptiometry (DEXA)
Originally developed to measure bone density, DEXA imaging is also used to precisely determine body fat content by using the density of various body tissues to identify which portions of the body are fat. This test is generally considered very accurate, but requires a great deal of expensive medical equipment and trained professionals to perform.

The most common method for discussing this subject and the one used primarily by researchers and advisory institutions is BMI. 

Health effects

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 to obesity, but 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 life expectancy by three years. A review in 2013 came to the result that being overweight significantly increases the risk of oligospermia and azoospermia in men.

Katherine 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 due to social discrimination. However, children under the age of eight are normally not affected.

Being overweight does not increase mortality in older people.

Causes

Being overweight is generally caused by the intake of more calories (by eating) than are expended by the body (by exercise and everyday living). Factors that may contribute to this imbalance include:

  • Alcoholism
  • Eating disorders (such as binge eating)
  • Genetic predisposition
  • Hormonal imbalances (e.g. hypothyroidism)
  • Insufficient or poor-quality sleep
  • Limited physical exercise and sedentary lifestyle
  • Poor nutrition
  • Metabolic disorders, which could be caused by repeated attempts to lose weight by weight cycling
  • Overeating
  • Psychotropic medication (e.g. olanzapine)
  • Smoking cessation and other stimulant withdrawal
  • Stress and anxiety

People who have insulin dependant diabetes and chronically overdose insulin may gain weight, while people who already are overweight may develop insulin tolerance, and in the long run type II diabetes.

Treatment

The usual treatments for overweight individuals is diet and physical exercise.

Dietitians generally recommend eating several balanced meals dispersed through the day, with a combination of progressive, primarily aerobic, physical exercise.

Because these general treatments help most case of obesity, they are common in all levels of overweight individuals.

Popular medicines to treat OBESITY:

Note: This information may not be actual at the time of reading. Always look for actual instructions in the package with the medication.
It is forbidden to use these materials without the advice of healthcare professional.

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