In Search of the Perfect Human Diet

I don't buy into this doc as there have been tons of movies and tons of books tackling the problem of obesity. Even if a diet works for awhile, most persons gain back the weight. No matter what anyone else has to say, just do what you know has to be done... steer clear of certain killer foods and exercise moderately. Everyone knows this precept. Not everything works for everybody. One can spout forth all sorts of theories, but very few people listen... that is if they even happen to catch the doc. If one is not sensible in doing what is best for one's own body, no documentary or books are going to convince an individual. I just don't aknowledge the constant barrage of info and changes in ideas that come forth every single year or two. Most of it is propaganda to make some big bucks, even if from reliable sources. I'm very skeptical.