Is the 40/30/30 Zone diet really healthy?

After analysing my food intake in the past couple of weeks, on most days I've consumed around 50-60% carbohydrates, 15-20% protein.  What intrigues me is that I thought I was eating quite healthily, but to make up 30% protein I'd need to eat a lot more meat and a lot less carbs, which goes against what I've learnt since childhood and I never feel full if I don't eat enough carbs ...

I can't really believe that such a dramatic change to my diet is needed for health, and websites such as British Nutrition Foundation says that "at least half the energy in our diets should come from carbohydrate, mostly as starchy carbohydrates."  What's everybody's views on this?

Carbohydrates

Definition
Carbohydrates are one of the main dietary components. This category of foods includes sugars, starches, and fiber.

Alternative Names
Starches; Simple sugars; Sugars; Complex carbohydrates; Diet - carbohydrates; Simple carbohydrates

Function
The primary function of carbohydrates is to provide energy for the body, especially the brain and the nervous system. Your liver breaks down carbohydrates into glucose (blood sugar), which is used for energy by the body.

Food Sources
Carbohydrates are classified as simple or complex. The classification depends on the chemical structure of the particular food source and reflects how quickly the sugar is digested and absorbed. Simple carbohydrates have one (single) or two (double) sugars while complex carbohydrates have three or more.

Examples of single sugars from foods include fructose (found in fruits) and galactose (found in milk products). Double sugars include lactose (found in dairy), maltose (found in certain vegetables and in beer), and sucrose (table sugar). Honey is also a double sugar, but unlike table sugar, contains a small amount of vitamins and minerals. (NOTE: honey should not be given to children under 1 year old.)

Complex carbohydrates, often referred to as "starchy" foods, include:
whole grain breads and cereals
starchy vegetables
legumes

Simple carbohydrates that contain vitamins and minerals occur naturally in:
fruits
milk and milk products
vegetables

Simple carbohydrates are also found in processed and refined sugars such as:
candy
table sugar
syrups (not including natural syrups such as maple)
regular carbonated beverages

Refined sugars provide calories, but lack vitamins, minerals, and fiber. Such simple sugars are often called "empty calories" and can lead to weight gain. Also, many refined foods, such as white flour, sugar, and polished rice, lack B vitamins and other important nutrients unless they are marked "enriched." It is healthiest to obtain carbohydrates, vitamins, and other nutrients in as natural a form as possible -- for example, from fruit instead of table sugar.

Recommendations
For most people, between 40% and 60% of total calories should come from carbohydrates, preferably from complex carbohydrates (starches) and naturally occurring sugars. Complex carbohydrates provide calories, vitamins, minerals, and fiber.

Foods that are high in processed, refined simple sugars provide calories, but they have few nutritional benefits. It is wise to limit such sugars.

To increase complex carbohydrates and healthy nutrients:
Eat more fruits and vegetables.
Eat more whole grains, rice, breads, and cereals.
Eat more legumes (beans, lentils, and dried peas).

Here are recommended serving sizes for foods high in carbohydrates:
Vegetables: 1 cup of raw vegetables, or 1/2 cup cooked vegetables, or 3/4 cup of vegetable juice
Fruits: 1 medium size fruit (such as 1 medium apple or 1 medium orange), 1/2 cup of a canned or chopped fruit, or 3/4 cup of fruit juice
Breads and cereals: 1 slice of bread; 1 ounce or 2/3 cup of ready-to-eat cereal; 1/2 cup of cooked rice, pasta, or cereal; 1/2 cup of cooked dry beans, lentils, or dried peas
Dairy: 1 cup of skim or lowfat milk
For information about how many servings are recommended see the food guide pyramid.

Here is a sample 2,000 Calorie menu of which 50-60% of the total calories are from carbohydrates.

Breakfast
1 cup of raspberries
1 1/2 cups of unsweetened cereal, with 1/2 sliced banana
1 cup of skim milk
1 slice of whole wheat toast
1 teaspoon of margarine
1 teaspoon of jelly
coffee or tea

Lunch
turkey pita pocket sandwich (2 slices of whole wheat pita bread, 3 ounces of lean turkey breast )
1/2 cup of shredded lettuce
1/2 cup of diced tomatoes
1/2 cup of green peppers
1 tablespoon of salad dressing
1 cup of skim milk
2 fresh, medium-sized peaches

Dinner
4 ounces of broiled salmon with 3 tablespoons of lemon juice, sprinkled with paprika
1 cup of pasta
1 dinner roll
6 steamed broccoli stalks with black pepper
salad:
1 cup lettuce
1/4 cup of sliced mushrooms
1/2 cup of sliced tomatoes
1/2 cup of sliced carrots
1 tablespoon of salad dressing
1/2 cup frozen unsweetened strawberries, sweetened with 1 teaspoon of sugar
1-inch slice of angel food cake
1 cup of skim milk

Side Effects
Excessive carbohydrates can cause an increase in the total caloric intake, causing obesity.
Deficient carbohydrates can cause a lack of calories (malnutrition), or excessive intake of fats to make up the calories

Thanks Burks, it's comforting to know that my diet does fall within the healthy range! Where did you get this information from btw?

been randomly saving facts about nutrition for the last year in a wordpad,

don't remember exactly where ;P

Amen! I was thinking the same thing--I do love carbs! If i don;t have any by evening, I start craving breads adn pasta. So sad isn't it? Also, it is easier for me to eat protein like chicken or turkey if I can just have a sandwich! LOL!