A Week in the Zone
Sears, Barry. New York: Harper Collins Publishers, Inc., 2000.

Authors Background:

Sears holds a doctorate degree in biochemistry but has no formal training in nutrition. This author had specialized in researching drug treatments for cancer and heart disease for several years. In the early 1990s however, Sears' focus shifted to the development of weight management program. Sears' Zone Diet program is based on the restoration and maintenance of eicosanoid hormones. According to the author, eicosanoids (produced by the body from dietary intake of unsaturated fats) are the "master switches that control virtually all human body functions" (e.g. cardiovascular system, immunity and metabolism). Sears uses misleading statements to describe the relationship between eicosanoids and weight control, supported by anecdotal case studies.

Diet Claims:

Elevated insulin levels due to eating too much carbohydrate are the culprit for storing excess body fat. Stabilizing insulin levels can be achieved by eating the author's prescribed ratio of carbohydrates to protein to fat- 40:30:30, respectively. Foods are categorized as either the “good” or “bad”.

“Basic Rules” of the Zone weight management as reported by author:

• Eat a Zone meal within an hour after waking up.
• Eat five times daily (3 meals plus 2 snacks).
• Never go 5 hours without eating.
• Eat more fruits & vegetables, less bread, grains and starchy food.
• Drink >8 cups water daily.
• Engage in moderate exercise and meditation daily.
• "Eating fat does not make you fat." But excess intake of carbohydrates is converted into body fat.
• "It's hard to lose weight by simply restricting calories...This effect is magnified by adherence to a low-calorie, high-carbohydrate diet, which causes your body to get out of the "Zone", that is breakdown body fat for energy."
• "Diets based on choice restriction and calorie limits usually fail."
• "Weight loss has little to do with will power." Dieters lack information on eating the right "Zone" foods, not will power."
• "Foods are either "good" or "bad." Ratio of protein to carbohydrate to fat (40:30:30) is the key ingredient for successful weight loss."

Weight Loss Promise:
Sears suggests a 1-1.5 lbs. per week weight loss.

Foods Allowed:

All types of lean poultry, seafood, egg whites, and low-fat dairy foods; most fruit and non-starchy vegetables; oatmeal and barley; small amounts of canola and olive oils. Meals and snacks include protein "blocks" (each contains 9 grams protein) coupled with carbohydrate "blocks" (each contains 7 grams carbohydrate).

Foods Restricted:

Corn, carrots, bananas, raisins, egg yolks, red or organ meats, processed foods and most grain products are limited to very small portions per meal. Also, carbohydrate foods with a high glycemic index (bread, cereals, rice, bagels, sweets, many fruits & juices, potatoes and snack chips) are not recommended. High fat meats and dairy foods, sweets and snack items are also restricted.

Sample Menu:

Breakfast:
6 large egg whites, scrambled with asparagus and 2 teaspoons olive oil
2/3 cup oatmeal
1 cup strawberries

Lunch:
Salad-
3 oz chicken breast
mixed greens, tomato
1 tablespoon dressing made with olive oil
Piece fresh fruit

Snack:
2 boiled egg whites with hummus filling

Dinner:
5 oz salmon with 1 tablespoon slivered almonds
2 cups steamed vegetables
1 cup berries

Snack:
1 oz soft cheese
Glass wine

Nutrition Analysis of Sample Menu:*

Calories:		1298
Protein:		113 g	32% calories
Total fat:	40 g	28% calories
Carbohydrate:	100	30% calories
Alcohol: 16 g   8%

Saturated fat:	9.3 g
Cholesterol:	195 mg 
Sodium:		1457 mg
Fiber:		28 g

*Menu items were imputed into NDS 2.93 database for analysis.

• Diet may be deficient in certain vitamins and minerals such as vitamin D, vitamin E, iron, magnesium and calcium as well as fiber.
• Sears diet principles are not supported by scientific research.
• Author also claims that the Zone diet is not restricted in calories or food choices. But the Zone food lists/sample menus indicate otherwise.
• Low carbohydrate intake significantly limits carbohydrate stores available in the body. Since carbohydrates are the body's preferred fuel supply, the Zone diet can impair dieters' energy level, especially during exercise.
• Calculating the "Zone" protein and carbohydrate "blocks" before eating all meals and snacks can be complicated for many dieters especially when dining out.
• Difficult program to follow long-term for those who enjoy eating chips, breads, fruits or other popular carbohydrate-rich foods.
  

Reviewed 1/07