Australia has one of the highest prevalences of overweight and obesity among developed countries with 62.8% of Australian Adults classified as overweight or obese (2011 ABS).
In 2016, about 13% of the world’s adult population was obese – triple the rate of obese adults in 1975.
What is obesity?
The World Health Organisation (WHO) defines overweight and obesity as “abnormal or excessive fat accumulation that may impair health.” Overweight and obesity is often classified with the Body Mass Index (BMI) which indexes weight to height. BMI is defined as a person’s weight in kilograms divided be height in meters squared. For adults, the WHO defines overweight and obesity as
- Overweight is a BMI greater than or equal to 25; and
- Obesity is a BMI greater than or equal to 30.
What impact does obesity have on people?
A number of medical studies have shown conclusively that overweight and obesity are associated with or aggravate a wide range of health problems such as
- High blood pressure
- Type 2 Diabetes
- Mental Health Issues
- Cardiovascular Disease
- Osteoarthritis & Joint Pain
- Sleep Apnoea
- Non-Alcoholic fatty liver disease
- Some cancers – including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon
In addition to these conditions, psychological problems such as depression and a lack of self-esteem and social problems (including various forms of discrimination as a result of being overweight) can be very debilitating and seriously affect an individual’s quality of life.
Health risks associated with overweight and obesity are directly related to how overweight an individual is. The heavier you are the greater the risk.
What causes obesity?
Overweight and obesity is caused by an imbalance between the calories we eat and the calories we use. If more body fuel (calories) is eaten than is used, a body fuel imbalance exists. The body is not able to rid itself of excess calories so it stores energy in the form of fat. Weight gain through excess calorie consumption is the result of an increase in body fat storage. This ability of our bodies to store body fuel as fat is a valuable survival mechanism that allowed our ancestor hunter and gatherers to survive when food was scarce by drawing on stored calories in fat. This mechanism however can work against us in the modern world where food is freely available and we don’t have to make much physical effort to get it.