Obviously, when one thinks of obesity, "healthy" doesn't come to mind. The exact definition of obesity is as follows: Obesity means having too much body fat. It is not the same as being overweight, which means weighing too much. It is common, serious and it affects some groups more than others. Obesity is in fact the leading cause of all preventable deaths. If you're a young adult, it is crucial for you to quit bad habits and start good ones. If you happen to be an adult and a parent, you need to start setting an example to the younger ones. Over the years, number of obesity among children is growing rapidly.