Flowering kale from my garden
The best foods to eat are plenty of fruits, vegetables, whole grains, legumes (beans), nuts, and seeds with moderate amounts of fish, poultry, low-fat dairy, red wine (or grape juice) and olive oil as the main fat.
This is the essense of the Mediterranean Diet.
Another healthy-way-of-eating is to follow a Vegetarian Diet; omitting the poultry above. There are varying degrees of vegetarianism -- some people omit fish too.
Veganism adheres to no meat, fish, dairy or even wearing animal products.