Popular Diets Reviewed: The Zone Diet
I remember when the Zone Diet rose to popularity - I think it was a huge part of the re-emergence of the low carb craze. I was in graduate school at the time and one of our assignments was to research a popular diet, follow it and then critique the plan. I chose the Zone Diet.
Written by Dr. Barry Sears, a biochemist, the Zone Diet is a low carb, high protein diet based on ratios of carbohydrate to protein and fat that Dr. Sears claims will produce optimum fat-burning and weight loss. The plan divides each meal into proportions, 40 percent of your calories should come from carbohydrates, 30 percent from protein and 30 percent from fat.
What to Eat
Each meal and snack should follow these ratios and include carbohydrate, protein and fat. Carbohydrates should come from mostly fruits and vegetables, beans and whole grains. Proteins should be lean meats and you should eat no more than 3 to 4 ounces per meal and 1 ounce per snack. Fats should come from healthy sources like olive and canola oils.
This diet encourages fresh vegetables, especially leafy green vegetables; fresh fruit; nuts; lean meats; monounsaturated fats and at least 8 glasses of water a day. But no foods are really prohibited on the Zone Diet; however, high sugar, high sodium and highly processed foods are discouraged.
In the Zone
The plan encourages three meals and two snacks (one in the afternoon and one in the evening). The timing of meals on this diet plan are pretty strict, it instructs you to eat within one hour of waking in the morning and then every 4 to 6 hours after a meal or 2 to 2 ½ hours after a snack - even if you aren’t hungry. In fact, if you aren’t hungry than the diet claims you are "in the zone". A meal should not exceed 500 calories and a snack should be within 100 calories.
The theory behind the Zone Diet is that when you consume too much carbohydrate a hormonal message to store fat is sent to the body. Dr. Sears claims that if you limit carbohydrates and balance them with equal proportions of protein and fat, you will enter "the zone", a state of more efficient fat burning, reduced stress, mental clarity, improved energy and better health.
Exercising in the Zone
The Zone Diet plan encourages regular physical activity, both aerobic and anaerobic. It also suggests eating a zone snack 30 minutes before working out so you can be in the zone and ensure you get the hormonal benefits of exercise.
My biggest memory of following the Zone Diet was how hard it was. It took a lot of work to get the ratios at each meal right. This was especially true when eating out, which I did daily in the cafeteria during the school day. In my opinion, a diet that is too complicated for a nutrition professional to want to follow is probably too complicated for most other people.
Lets’ face it, most people find calorie counting to be too tedious to do on a daily basis, this is why the Weight Watcher’s point system is so popular. For the most part, people don’t’ want to deal with lots of numbers. The Zone Diet is calorie counting to the extreme. Not only do you have to count the calories you are eating but then you have to determine what percentage of your calories is coming from carbs, protein and fat.
Any weight loss on the Zone Diet is due to the decrease in calories, not to the ratio of carbohydrates to protein and fat in each meal and snack. The sample menus included in the book total about 1200 to 1300 calories, which would provide weight loss for most individuals. However, that calorie level is far too low for most people to be able adhere to over the long-term. And I find it unlikely that people would be able to follow the Zone Diet as a lifestyle.
Further, I have concerns about the ratios. The diet limits carbohydrates to 40 percent of your total calories, which is lower than standard recommendations. The general consensus among health professionals is that carbohydrates should actually make up 50 to 60 percent of your total calories.
*** Grade: B.** This diet encourages a well-balanced diet that includes all food groups. The nutrition recommendations of the Zone Diet follow those of the Dietary Guidelines including fresh fruits and vegetables, whole grains, lean meats and monounsaturated fats. However, the recommendation for percent of calories from carbohydrates is not consistent with those generally accepted by health professionals.
*** Popular Diet Rating Syste:** This diet meets accepted standards for a healthy well-balanced diet. It recommends food from all food groups with an emphasis on healthy choices within each food group.
B: This diet meets most accepted standards for a healthy well-balanced diet. It emphasizes healthy foods but does not include food from all food groups.
C: This diet only meets some accepted standards for a healthy well-balanced diet. It does not differentiate between food choices in each food group and therefore does not emphasize healthy foods.
D: This diet does only meets one or two accepted standards for a healthy well-balanced diet.
F: This diet does not meet any accepted standards for a healthy well-balanced diet. It does not differentiate between healthy foods and unhealthy foods and/or does not meet caloric needs.
Read all of our reviews of popular diets.
Heather wrote for HealthCentral as a patient expert for Food & Nutrition.