What is Obesity ?

Obesity is a medical condition defined in terms of body weight, either body weight compared with ideal body weight, or body weight combined with height using a quantity called body mass index (BMI).

The general characteristics of obesity are excess weight due to the accumulation of considerable excess body fat, i.e. an extent of body fat that has or is likely to have long-term adverse effects on health, potentially leading to life-threatening medical conditions and complications (see health risks of obesity) and therefore also reduced life expectancy.

Definition of obesity:

There are two definitions of obesity. Different sources state one or the other, or both:

More about obesity:

It is likely that most people who are overweight are aware that their weight is excessive. However, obese people do not necessarily realize that they are so overweight that it may lead to health problems in the short, medium and long-term - depending on their BMI, their current state of health and other lifestyle considerations such as exercise, stress, state of mind, and habits such as intake of alcohol, drugs or cigarette smoke. That is not surprising because excessive body weight is becoming more common and hence may be considered relatively 'normal' in some countries and societies. Both individual men and women's acceptance of their own unhealthy weight and the increasing prevalence of obesity in the general population in some places contributes to the health problems and associated costs that those individuals and societies (i.e. societies that pay for healthcare collectively, e.g. in the form of the UK NHS) are likely to face in the future.

For example, the 10 causes of obesity listed on this website includes 7. Environmental Factors, i.e.

"The circumstances in which someone grew up, including the food he or she was given and the habits and attitudes that he or she observed and was influenced by can all combine to affect that person's own habits, attitudes and beliefs throughout life. This can affect the person's weight among many other aspects of his or her life., incl. e.g. educational attainment, income, relationships, and so on."

It makes sense to be aware of the health risks of obesity and the extent to which they may apply to oneself or to the people and / or animals one cares for. Understanding what obesity is and what its implications are does not excuse judging people affected by obesity. The many possible causes of obesity include some that may be especially challenging for certain people to overcome (e.g. due to psychological factors, hormones, prescribed medications, genetics). An apparently overweight person may be achieving more weight loss and/or other health success than a passing on-looker, or even his/her friends and family realize. It is, at the very least, unkind to make harsh assumptions about others. Some people have suggested that it is irresponsible not to make every possible effort to maintain one's own personal health so far as possible, which includes maintaining a healthy weight for one's body size via lifestyle choices such as a healthy diet and appropriate physical exercise.

See also what is a balanced diet?, how to increase metabolism and possible effects of overnutrition.