Obesity and overweight can be in the simplest form defined as excessive or abnormal weight and fat accumulation, which can cause negative effects on health. The body mass index (BMI) is one of the most popular tools to measure overweight and obesity at both, children and adults. As another definition, made by the National Institutes of Health, obesity is a BMI of 30 and more. The ideal weight has to be defined before the definition of obesity. This measurement is including numerous factors like age, sex, height and the persons build.

BMI the key index in obesity measurement of describing the body weight related to the individuals health and it also closely relates with the total body fat content, and the accent is on fat, because there can be people seeming to be overweight, but they are only muscular having low risks of disease development.

Obesity and overweight can highly increase the risk developing several diseases, including cancer, diabetes, heart diseases, stroke, high blood pressure, gallstones or osteoarthritis.

Obesity can be caused by both behavioral and genetic factors and usually a dietary change is not enough as a treatment. Usually obesity treatments include supplementation with medicaments, counseling and support and exercise. The majority of cases including obesity are often caused by an excess of calorie intake, which is converted in body fat. Cases of obesity generated by genetic factors are minimal, starting with childhood the chance to become overweight as an adult can be influenced by parental contributions including diet plans and exercise.

Obesity can have severe consequences, usually at adulthood, but children and adolescents can also have health problems if being obese. Obesity usually affects the endocrine system leading to adrenalin hormone; sex hormone and insulin respond changes. Unfortunately, as the number of obese people has grown, the risk of diabetes type 2 developments, starting from adolescence has also grown. Psychological consequences are also often and in some cases quite severe, mostly at childhood. Children are more easily affected by opinions and negative opinions can harm their self esteem and way of life.