I think a good summary of the things that most people agree on to some extent is Michael Pollan's advice from The Omnivore's Dilemma (2006): "Eat food. Not too much. Mostly plants."
Obviously there are a lot of details to fill in, but the first part boils down to avoiding processed foods. The other two are pretty straightforward.
As mentioned by others, physical activity and stress management are just as important, and social connections tend to be positively correlated with health as well.
I think the problems come in when you realize how many people pushing specific diets have agendas beyond health, as well as the fact that there is no specific diet that is perfect for everyone.
Obviously there are a lot of details to fill in, but the first part boils down to avoiding processed foods. The other two are pretty straightforward.
As mentioned by others, physical activity and stress management are just as important, and social connections tend to be positively correlated with health as well.
I think the problems come in when you realize how many people pushing specific diets have agendas beyond health, as well as the fact that there is no specific diet that is perfect for everyone.