Health...what to eat and what not to eat???

Whats bad for us and whats not? At one time experts said that diet cokes were better for you than regular, splenda was much better for you than real sugar, 2% milk was better than whole milk, and fat free butter was better for you than real butter. Now you hear that all the healthy food is just making us crave more of the food that is bad for you and etc. but really I never actually hear a real solution to all this and the reasons behind it all. If I wanted to know I guess that I could look it up to see what experts have to say, but not everyone has access to do that and doctors always talk about how important it is to eat healthy and how the obesity rate is going up but do they really advertises the right foods to eat and the reason that some healthy foods are not as good as they once said.....not that often. I'm sure that many people today are unsure of whats good and whats bad. I personally like to use splenda in my food instead of sugar because it taste just as good and it has less calories but does it make me crave more foods that have real sugar in it? Who knows??? Doctors or experts in this field should do more research and more advertising of the right foods.