Obesity is a complex and chronic medical condition characterized by the excessive accumulation of
body fat to a degree that adversely affects an individual’s health. It is a multifaceted issue, involving
genetic, environmental, behavioral, and socio-economic factors. Obesity significantly increases the
risk of various health problems, including cardiovascular diseases, type 2 diabetes, musculoskeletal
disorders, and certain cancers, as well as the psychological strain of weight stigma, making it a
critical global public health concern. Effective management strategies encompass a combination of
psychological interventions (addressing sleep, stress, self-image…), medical interventions, and, for
some, surgical procedures that build a foundation for the successful implementation of healthy
physical activity and diet.
PART I: WHAT IS OBESITY
The definition of obesity has evolved during the last few years, even though it was recognized as a
disease, for example, by the American Medical Association about 20 years ago. This text will not
dwell on what precedes the current understanding; instead, we will focus on the here and now.
Please note, there is an ongoing project where a number of world renown obesity experts are
discussing both terminology and diagnose criteria. The result of this project will be presented some
time during the spring of 2024, so the terms used in these texts might have to be revised later.
Obesity is a chronic, progressive, relapsing, and treatable multifactorial, neurobehavioral disease.
This means that obesity can be clustered together with other metabolic diseases such as
hyperlipidemia, hypertension, and type 2 diabetes. Often, obesity is the root cause of these
Obesity is the excessive accumulation of body fat to a degree that adversely affects an individual’s
health; or in another way of phrasing it: Adiposity-Based Chronic Disease (ABCD). This latter term is
being used more frequently when describing obesity. A perhaps even more specific term is actually
adiposopathy, which can be translated into adipose tissue malfunction and pathologic fat storage
(“fat in the wrong place”).
Let’s backtrack slightly and compare with healthy fat storage. Dietary fat is normally stored in special
cells called adipocytes, which then form adipose tissue. The preferred storage area for fat is under
the skin, known as subcutaneous adipose tissue. Fat is safely stored here and has several benign
effects, such as serving as a reservoir of energy and assisting in temperature regulation.
Although subcutaneous fat can be found all over the body, there are certain points where surplus
tends to accumulate. For women, thighs and buttocks are preferred storage areas, and for men, it’s
the lower back. As long as fat remains in these subcutaneous storage areas, the metabolic
consequences are minimal. There might be joint and movement problems that can have a negative
health impact when the amount of adipose tissue becomes substantial. In addition, for people living
with larger bodies, weight stigma based on myth, biases, prejudices and unhealthy beauty standards
will have a detrimental health effect. Due to the importance of weight stigma on health, it will be
covered in a separate entry.
So, when does storage become problematic? When these subcutaneous storage areas can no longer
store incoming fat due to various reasons, less suitable areas have to start storing fat. These less
suitable areas include excess storage of fat in the muscle tissue and in and around internal organs
such as the liver, pancreas, and kidney. These latter fat deposits are collectively called visceral fat
(sometimes called abdominal fat), and metabolic problems start to arise. One of the initial metabolic
derangements is increased insulin resistance (which actually often precedes the unhealthy fat
storage), followed by an increase in blood lipids and blood pressure, as well as an increase in various
Importantly, the degree of body fatness at which storage of fat goes from metabolic innocuous to
harmful varies greatly between individuals. Some can store a great deal of fat in their subcutaneous
tissue and usually have no major metabolic problems, whereas others begin experiencing metabolic
problems at a much lower percentage of body fat.
In summary, Obesity = fat stored in the wrong spot and in excess for healthy daily living.