Question

Why aren't magazine photos a good representation of what a healthy person looks like?

Answer 1

There could be many answers to this question, but mainly, two are very common.

First, magazines tend to use Photoshop on their photographs in order to adjust them to the overall graphic design that any given magazine establishes as its own, adulterating, so to speak, the realism of their contents, perhaps deviating from what a healthy human body would probably look like.

Second, there is a global widespread aesthetic that tends to idealize unrealistic body types, both of men and women, though more noticeably in the latter. These body types do not necessarily conform to what a healthy human body would look like; having said that, there is no reason to demonize these body types since some could be perfectly healthy, even if slender or otherwise.    

Answer 2

Magazine photos are usually of people who are anorexic or who starve themselves. they are not a representation at all of normal healthy people. Most of the photos in magazine are photoshopped as well to look like they have nothing wrong with them or no blemishes or fat at all.