Scientists keep on embarrassing themselves.
They know it too, and the ultimate recommendation usually ends up being to keep your diet varied so that you don’t get too much of any one thing.
Margarine? Butter!
Canola oil? olive oil!
Red meat? Chicken now fish! Now red meat does not cause heart disease!
White bread? Natural grains now glutin (sp?) free!
I think I saw a new food pyramid and it was upside down!
How did I ever live so long?