t colin campbell, michael pollan, & Tim Robbins are probably the 3 most important writers on this topic. while the latter two definitely write more to stir reaction, prof. campbell basically published his results in the china study.
basically, all three writers/experts agree that a vegetarian diet consisting of unprocessed foods is the best (although not foolproof) way to ensure that you will lead a long and disease free life.
the modern food revolution is only about 60 odd years old at this point - human evolution cannot keep up with how quickly our food has changed and how quickly our caloric intake has increased. perhaps in 10,000 years we will be able to find a way to absorb nutrients from krispy kreme donuts and pizza but for now its best to stick low on the food chain and as michael pollan say - "Eat Food, Not Too Much, Mostly Plants".
Anyone looking for sources or more info i recommend the following:
The China Study - T Colin Campbell
The Food Revolution (Or Diet For a New America) - Tim Robbins
The Omnivore Dilemma (Michael Pollan)
Healthy At 100 - Tim Robbins
one last note - Diet for a new america was written in 1988!!! This information has been out there for decades - politics and misinformation has kept it relatively out of mainstream media and on the sidelines but the statistics and information is out there for those who take the time to look...