The Zone Diet's eating plan is a combination of a small amount of proteins, fats, and carbohydrates in the form of fiber-rich vegetables and fruits.
The Zone Diet recommends

Carbohydrates should be twice the size of the protein portion. Fruits and vegetables are the preferred source of carbohydrates.

Proteins should be eaten with every meal and at every snack. These include chicken, fish, beef, turkey, egg whites, low-fat cheeses, tofu, veal or low-fat pork.

Monounsaturated fats such as olive oil, almonds or avocados are the ideal choice of fats.

Supplementation with high-dose omega-3 fish oil is also a very important component of the Zone Diet regime.
The Zone Diet does not actually prohibit any particular food group; however the following food should be consumed in moderation-

Food with high fat and carbohydrates such as brown rice, grains, starches, and pastas should be avoided.

Fruits like bananas, raisins, grapes and figs.

Vegetables like potatoes, peas, corn and carrot.

Avoid sugar in all forms.

Avoid alcohol.

Avoid beverages containing caffeine.