Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health, leading to reduced life expectancy and/or increased health problems. In 2011-12, 62.8% of Australians aged 18 years and over were overweight or obese, comprised of 35.3% overweight and 27.5% obese. A further 35.5% were of normal weight and 1.7% were underweight. The prevalence of overweight and obesity has increased in Australia over time, from 56.3% in 1995 and 61.2% in 2007-08. Dieting and exercising are the main treatments for obesity.
Diet quality can be improved by reducing the consumption of energy-dense foods, such as those high in fat and sugars, and by increasing the intake of dietary fiber. Excess weight, especially obesity, is a major risk factor for cardiovascular disease, Type 2 diabetes, some musculoskeletal conditions and some cancers. As the level of excess weight increases, so does the risk of developing these conditions. In addition, being overweight can hamper the ability to control or manage chronic disorders.