I've done some research on the matter of eating healthy for living a more productive life. Interesting enough, what we need is a high protein and animal fat diet, with lots of raw vegetables with very limited fruits. Of course we can't forget about the most important ingredient of all, clean water.
What you need to stay away from is carbohydrates, grains, sugar, and salt.
We have a carnivorous anatomy and we need protein to survive. There is no doubt about that. The human brain is made up of mostly fat. So why would you limit your body with the natural raw materials it needs for proper functions.
Vegetables should be eaten raw because when you cook it you lose up to 90% of the nutrients. Eating any soups mean that you are basicly eating salt water. Very bad for you blood pressure.
Why limit your fruits? It has small levels of fructose which in large quantities is unhealthy for you.
The most important ingredient is fresh clean water. Why? Because with out it your body would shut down in 72 hours. Do not think for a second that sport drinks and fruit drinks are better then plain water. In those drinks you have high fructose corn syrup and sugar which is unhealthy.