Being overweight or fat is having more body fat than is optimally healthy. Being overweight is especially common where food supplies are plentiful and lifestyles are sedentary. As of 2003, excess weight reached epidemic proportions globally, with more than 1 billion adults being either overweight or obese. 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; however, the accumulation of too much storage fat can impair movement, flexibility, and alter the appearance of the body.

• The degree to which a person is overweight is generally described by the 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 29.9 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 and 29.9. 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 following 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.

BMI provides a significantly more accurate representation of body fat content than simply measuring a person's weight. It is only moderately correlated with both body fat percentage and body fat mass (R² of 0.68). It does not take into account certain factors such as pregnancy or bodybuilding; however, the BMI is an accurate reflection of fat percentage in the majority of the adult population.

• 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

BVI uses 3D software to create an accurate 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.

BVI measures where a person's weight and the fat are located on the body, rather than total weight or total fat content and places emphasis on the weight carried around the abdomen, commonly known as central obesity. There has been an acceptance in recent years that abdominal fat and weight around the abdomen constitute a greater health risk.

• Simple weighing

A 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 measure 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. This method can be reasonably accurate for many people, but it assumes particular fat distribution patterns over the body—which may not apply to all individuals, and does not account for fat deposits not directly under the skin. Also, as the measurement and analysis generally involves a high degree of practice and interpretation, an accurate result requires that a professional perform it. It cannot generally be done by patients themselves.

Journal Homepage: https://obesity.imedpub.com/

Regards,
Catherine
Journal Co-Ordinator
Journal of Obesity and Eating Disorders