Do you know about obesity? Obesity means having excess body fat. For adults 35 and older, having a body mass index (BMI) greater than 30 is considered obese. Nowadays, it becomes a common problem around the world. It has been increasing rapidly throughout the world. In the United States, over two-thirds of adults are overweight， and one in three Americans is obese.Roughly 300,000 deaths per year are directly related to obesity. More than 80% of these deaths are in patients with a BMI over 30. For patients with a BMI over 40, life expectancy is reduces significantly Obesity cause a really serious health consequences. First, the risk of type 2 diabetes increases with the degree and duration of obesity.It is associated with central obesity; a person with central obesity has excess fat around his/her waist, so that the body is shaped like an apple. Also, Hypertension is common among obese adults. Obesity has also been linked to cancer of the colon in men and women, cancer of the rectum and prostate in men, and cancer of the gall bladder and uterus in women. Furthermore, heart attack is also caused by obesity. A Finnish study showed that for every 1 kilogram (2.2 pounds) increase in body weight, the risk of death from coronary artery disease increased by 1%. It related conditions include heart disease, stroke, type 2 diabetes and certain types of cancer, some of the leading causes of preventable death. The obesity not only affect the person themselves, but also the whole of society. The cost of obesity to Australia's economy in 1989-1990 was around 2% of the total healthcare budget Particularly in 2005, $3.767 million was depleted, of which 23.2% was from the direct financial cost to the Australian health system and the rest was indirect cost such as the loss of productivity, carer costs, deadweight loss (DWL) from transfers and other indirect costs as seen in the figure below. In 2008, the figures were revised to $8.3 billion (total cost of obesity) and $2.0 bil