It's very important to take steps to tackle obesity because, as well as causing obvious physical changes, it can lead to a number of serious and potentially life-threatening conditions, such as: type 2 diabetes coronary heart disease some types of cancer, such as breast cancer and bowel cancer stroke Obesity can also affect your quality of life and lead to psychological problems, such as depression and low self-esteem (see below for more information about the health problems associated with obesity).