Obesity or overweight are defined as abnormal or excessive fat accumulation that presents a risk to health. A crude population measure of obesity is the body mass index (BMI), a person’s weight (in kilogram) divided by square of his or her height(in meters). A person with a BMI of 30 or more is generally considered obese. A person with a BMI equal to or more than 25 is considered overweight. Overweight or Obesity are major risk factors for a number of diseases, including diabetes, cardiovascular diseases, and cancer. Key facts Worldwide Obesity has more than doubled since 1980. In 2014, more than 1.9 billion adults, 16 years and older, were overweight. Of these over 600 million were obese. 39% of adults aged 18 years and over were overweight in 2014 and 13% were obese. Most of the world’s population live in countries where overweight and obesity kills more people than underweight. 42 million children under the age of 5 were overweight or obese in 2013. Obesity is preventable. What are Overweight and Obesity? Overweight and Obesity are defined as abnormal or excessive fat accumulation that may impair health. The WHO definition is: a BMI greater than or equal to 25 is overweight a BMI greater than or equal to 30 is obesity. BMI provides the most useful population-level measure of overweight and obesity as it is the same for both sexes and for all ages of adults. However, it should be considered a rough guide because it may not correspond to the same degree of fatness in different individuals. What causes Obesity? The fundamental cause of obesity and overweight is an energy imbalance between calories consumed and calories burnt. Globally there has been an increased intake of energy-dense foods that are high in fat; and an increase in physical inactivity due to the increasingly sedentary nature of many forms of work, changing modes of transportation and increasing urbanization. Changes in dietary and physical activity patterns are often the result of environmental and societal changes associated with the development and lack of supportive policies in sectors such as health, agriculture, transport, urban planning, environment, food processing, distribution, marketing, and education. What are the common health consequences of Obesity and Overweight?
- Cardiovascular diseases (mainly heart disease and stroke), which were the leading cause of death in 2012.
- Musculoskeletal disorders (especially osteoarthritis – a highly disabling degenerative disease of the joints)
- Cancer (endometrial, breast, and colon).
The risk for these non communicable diseases increases, with an increase in BMI. Childhood obesity is associated with a higher chance of obesity, premature death and disability in adulthood. But in addition to increased future risks, obese children experience breathing difficulties, increased risk of fractures, hypertension, early markers of cardiovascular disease, insulin resistance, and psychological effects. To read how to fight it, wait for Part 2!