There are a number of reasons that so many people have an unhealthy amount of body fat. Some are simply lacking the motivation required to abstain from eating junk food and monitor their calories.
For others, the problem has nothing to do with motivation and is more a product of not knowing what they ought to be doing to build their ideal physique.
This issue doesn’t stem from the right information being unavailable to them. You can find quality instructions for losing fat and building muscle on a number of reputable websites, within books, and in many online programs.