> Citation needed! it's not actually difficult

It's simple, and people think simple = easy. It's simple, yet very difficult. Walking up 1,000 stairs is also simple, you just put one foot in front of the other until you're up. But it's hard. We know weight loss is hard because of how many people are obese. Most obese people have tried to lose weight many, many times and have failed. If it was easy, they wouldn't fail. Evidently it is difficult, and no other perspective is reasonable.