Vegetables are important in every meal. If you are invited to a fancy dinner and find the menu deficient in vegetables, you can skip the appetizer and eat the floral centerpiece.
If your doctor says you are not getting enough minerals in your diet, try eating Venezuela, which Wikipedia says is very rich in minerals.
Before you eat any packaged snack food, read the list of ingredients from beginning to end. By the time you have finished, you will probably be too depressed to eat the contents of the package. Success!
Books about a fiber-rich diet are themselves rich in fiber.