Athletes and bodybuilders have managed to have their diet and fitness nailed for decades, it's only the common joe that seems to be confused.
This issue is less the fault of science and more the fault of marketing. Marketers will latch on to any scientific study, however tenuous, to push a product and the news will happily inflate their claims for headlines, e.g. the thoroughly debunked '1 glass of red wine is the same as an hour of exercise' study released recently. It's not scientists making these claims, its marketers and news reporters.
Corporations that lobby politicians to to sell more of their products also aren't helping. The US food pyramid isn't the fault of scientists, its the fault of farmers wanting to sell more grain. Michelle Obama's attempts to revamp America's food issues are being thwarted by huge corporations with deep pockets and news reporters siding with the opposition doing their utmost to paint any attempts for nutritional revamp in a bad light. None of those guys are scientists.
If you want to learn about nutrition and exercise get away from the marketing and the news and start looking at what athletes and bodybuilders are doing. They've been doing it for a long time and if you look closely a lot of what they do is backed up by science. Eating grilled chicken/steak/fish with brown rice and steamed vegetables and doing weight lifting/high intensity interval training doesn't grab headlines though and takes effort.