So, for our health, the “best” diet is a theme: an emphasis on vegetables, fruits, whole grains, beans, lentils, nuts, seeds, and plain water for thirst. That can be with or without seafood; with or without dairy; with or without eggs; with or without some meat; high or low in total fat.
The best foods don’t even have labels, because they are just one ingredient: avocado, lentils, blueberries, broccoli, almonds, etc.
From The Last Conversation You’ll Ever Need to Have About Eating Right, a conversation with Mark Bittman.
I have a poor diet. Out of laziness, mostly. It helps to read articles like this occasionally to remind myself to be better.