Zone Diet Overview

Scorecard

Overall
Weight Loss Short-term
Weight Loss Long-term
Easy to Follow
Nutrition
Safety
For Diabetes
For Heart Health

Scores are based on experts' reviews

Pros & Cons

  • No foods are banned
  • Frequent meals and snacks
  • Tedious portioning
  • Limited daily calories

Do's & Don'ts

Do: Have two snacks a day See more Do's & Don'ts

Overview

Type:

Balanced.

Resembles these U.S. News-rated diets:

Glycemic-Index Diet, Nutrisystem

The aim:

Weight loss.

The claim:

You’ll drop 1 to 2 pounds weekly.

The theory:

Food is like a drug, says Zone creator Barry Sears, a biochemist. You have to take the right dose at the right time. The key to weight loss is achieving proper hormone balance and keeping your blood sugar stable. According to Sears, elevated levels of insulin, a hormone that helps control blood sugar, and other hormones cause you to pack on pounds because they promote inflammation, which he believes is a chief driver of the obesity epidemic. You can make sure your insulin and other inflammation-promoting hormones stay “in the zone,” not too high or low, by eating foods at every meal in the right proportions: 40 percent carbs, 30 percent protein, and 30 percent fat. The body needs the right balance of these nutrients to stay healthy, slim, and operate at peak performance, he says.

How does the Zone Diet work?

The Zone diet typically caps daily calories for women at 1,200 and 1,500 for men. That’s two-thirds to three-quarters of the amount generally recommended for healthy people. You’ll eat five times a day: three meals and two snacks. Each meal should contain 40 percent carbs, 30 percent protein, and 30 percent healthy fat. The only measuring tools you need are your hand and your eye, Sears says. When making dinner, for example, divide your plate into three equal sections. Put a low-fat protein in one section—no more than can fit in the palm of your hand, which for most women equates to 3 ounces; 4 ounces for men. Then fill the other two sections with colorful carbs (think fresh fruit or steamed veggies). Top it off with a dash of a healthy fat—olive oil, fish oil, almonds, or avocado, for example—and you’re set.

Although no food is off limits, certain types are encouraged. Optimal protein choices include skinless chicken, turkey, fish, egg whites, low-fat dairy, tofu, and soy meat substitutes. Carbs are either “good” or “bad,” and dieters are instructed to choose those that are low on the glycemic index (GI), a ranking of how carbs affect blood sugar. Low-GI carbs are said to keep your blood sugar and metabolism steady—and you feeling fuller longer—while high-GI, “bad” carbs do the opposite. Your best bets are vegetables (except starchy corn and carrots), fruits (except bananas and raisins), and oatmeal and barley. Stay away from pasta, bread, bagels, cereals, and potatoes. And while small amounts of healthy fats are added to each meal, avoid fatty red meat, egg yolks, liver and other organ meats, and processed foods—all high in saturated fat.

Almost as important as what you eat is when. Meal and snack timing are crucial on Zone. If you don’t eat often enough, your blood sugar will dip, triggering hunger pangs. You should never go more than five hours without eating. Have breakfast within one hour of waking. If that’s at 7 a.m., for example, have lunch at noon, a snack at 5 p.m., dinner at 7 p.m., and another snack at 11 p.m.

Will you lose weight?

What limited research there is on Zone suggests it’s moderately effective for weight loss. But the 40:30:30 carb/protein/fat ratio is no magic bullet, and in fact, scientific evidence casts doubt on its efficacy.

  • A 2007 study published in the Journal of the American Medical Association divided about 300 overweight or obese women into groups and assigned them to one of four types of diets: low-carb (Atkins), low-fat (Ornish), low saturated-fat/moderate-carb (LEARN), and roughly equal parts protein, fat, and carb (Zone). At two months, Zone dieters had lost about 6 pounds, the same as those in the other groups—except for the Atkins group, which lost 9½ pounds. After a year, weight loss for the Zone group averaged about 3.5 pounds— less than what other groups lost. The Atkins group lost 10 pounds compared to 6 for the LEARN group and 5 for the Ornish group.
  • In another study of 160 people assigned to either Zone, Atkins, Weight Watchers, or the Ornish diet, weight loss was modest for all groups, according to findings published in the Journal of the American Medical Association in 2005. After one year, the Zone dieters had lost an average of 7 pounds, compared with 7.3 for the Ornish group, 6.6 for Weight Watchers, and 4.6 for Atkins, and fewer Zone (and Weight Watchers) dieters had dropped out (about 35 percent) than Atkins and Ornish dieters (about 50 percent). About 25 percent of dieters in all groups had lost more than 5 percent of their initial body weight, and 10 percent had lost more than 10 percent of their starting weight. That’s important because if you’re overweight, losing just 5 to 10 percent of your current weight can help stave off some diseases.
  • A review of the Zone diet published in 2003 in the Journal of the American College of Nutrition concluded that scientific evidence “casts strong doubt” on its health claims and theory. Weight loss on the plan is explained by restricting calories, not the 40:30:30 ratio, the researchers said. In fact, there are “scientific contradictions,” because following such a ratio does not promote fat-burning or weight loss more than any other nutritionally-sound diet does. The ratio could even cause insulin levels to spike, an outcome the diet aims to avoid, according to the report.

Does it have cardiovascular benefits?

Research is scant, but does suggest that the Zone diet could help the heart by bringing down cholesterol levels.

  • In the 2005 Journal of the American Medical Association study cited in the weight-loss section above, Zone dieters who completed the 12-month regimen reduced their total cholesterol by an average of 7 percent (not quite as dramatic as Ornish, slightly better than Weight Watchers, and much better than Atkins). Results were similar for “bad” LDL cholesterol: down 13 percent for Zone, compared with 19 percent for Ornish and 10 percent for both Atkins and Weight Watchers.

Can it prevent or control diabetes?

No good evidence suggests that Zone can do either. However, being overweight is one of the biggest risk factors for type 2 diabetes. If the Zone diet helps you lose weight and keep it off, you’ll almost certainly tilt the odds in your favor. And it emphasizes the right foods and discourages the wrong ones.

  • In the Journal of the American College of Nutrition analysis mentioned in the weight loss section, the researchers found no evidence that the Zone’s insulin-balancing claims have a positive effect. Eating carbs, protein, and fat in the recommended 40:30:30 ratio at each meal does not improve the way insulin responds to food and does not help stave off or manage diabetes, according to the review.

Are there health risks?

No indications of serious risks or side effects have surfaced. The plan is generally safe for everyone. However, if you have a health condition, check with your doctor to ensure the Zone diet is right for you.

How well does it conform to accepted dietary guidelines?

Fat. Thanks to its emphasis on fruits, veggies, and lean meat, you’ll have no problem staying within the government’s recommendation that between 20 to 35 percent of daily calories come from fat. Zone says fat should supply 30 percent of daily calories, but emphasizes the healthy kind, not saturated or trans fat.

Protein. It’s within the acceptable range for protein consumption.

Carbohydrates. You’ll fall slightly short of the recommended 45 to 65 percent of daily calories from carbs.

Salt. The majority of Americans eat too much salt. The recommended daily maximum is 2,300 milligrams, but if you’re 51 or older or African-American, or have hypertension, diabetes, or chronic kidney disease, that limit is 1,500 mg. Because fruits and (unsalted) veggies provide most of your calories on the Zone diet, you shouldn’t have trouble. A sample daily menu came in at 1,346 mg.

Other key nutrients. The 2010 Dietary Guidelines call these “nutrients of concern” because many Americans get too little of one or more of them:

  • Fiber. Getting the recommended daily amount of 22 to 34 grams for adults helps you feel full and promotes good digestion. Veggies, fruits, beans, and whole grains—all major sources—are encouraged on Zone, so you should easily meet the recommendation.
  • Potassium. A sufficient amount of this important nutrient, according to the 2010 Dietary Guidelines, counters salt’s ability to raise blood pressure, decreases bone loss, and reduces the risk of developing kidney stones. It’s not that easy to get the recommended daily 4,700 mg. from food. (Bananas are high in potassium, yet you’d have to eat 11 a day.) The majority of Americans take in far too little. Because you’re almost certainly eating more fruits and veggies than you were before, you’ll likely get more potassium than most.
  • Calcium. It’s essential not only to build and maintain bones but to make blood vessels and muscles function properly. Many Americans don’t get enough. Women and anyone older than 50 should try especially hard to meet the government’s recommendation of 1,000 to 1,300 mg. While difficult to meet the goal—a sample daily Zone menu fell short—you cansucceed with low-fat dairy products like cheese and yogurt.
  • Vitamin B-12. Adults should shoot for 2.4 micrograms of this nutrient, which is critical for proper cell metabolism. Salmon, trout, eggs, and yogurt are good sources.
  • Vitamin D. Adults who don’t get enough sunlight need to meet the government’s 15 microgram recommendation with food or a supplement to lower the risk of bone fractures. A sample daily Zone menu fell far short. But eating just 3 ounces of sockeye salmon, which packs almost 20 micrograms of vitamin D, will satisfy the requirement.

Supplement recommended? Sears advises an omega-3 fatty acid supplement, since it’s difficult to get enough omega-3s from food, particularly if you don’t like fish.

How easy is it to follow?

Making sure each meal contains the right percentage of carbs, protein, and healthy fat can be tedious. And some dieters may find Zone’s strict eating schedule—breakfast within one hour of waking up, and then snacks and meals every five hours—daunting.

Convenience:

Recipes are available, though ensuring meals conform to the 40:30:30 rule could prove time-consuming. Dining out is doable. The company’s online and printed resources may be helpful.

Recipes. Sears’ book A Week in the Zone offers breakfast, lunch, dinner, and dessert recipes, as well as snack ideas. Choices range from chicken fajitas to seafood salad.

Eating out. Allowed as long as you ignore the bread basket, choose a low-fat protein entrée, and order vegetables instead of starches and grains. Once your meal arrives, examine the size of your entrée. If it’s larger than your palm, plan to take some home.

Alcohol. Beer and wine contain carbs, and all alcoholic beverages add calories. Moderation is key; most experts suggest two drinks a day for men and one for women. Red wine is best, Sears says, since it’s packed with polyphenols, antioxidants that purportedly thwart inflammation and other health problems.

Timesavers. You can take advantage of Zone 1-2-3 foods, available for purchase online. These aren’t full meals, but individual items like pasta, rolls, pizza, and cookies. Each contains 1 gram of fat for every 2 grams of protein and 3 grams of carbohydrates—a ratio Sears believes suppresses appetite for up to six hours. They’re designed to make following the diet easier, but aren’t required.

Extras. Online membership at zonediet.com is free and includes access to a body fat calculator, monthly newsletters, recipes, and podcasts and videocasts on health topics. If you purchase Zone 1-2-3 foods, you’ll be matched with a Zone Coach who you can call between business hours on week days with questions and for emotional support. Coaches have passed company certification tests to assist clients with product ordering and offer practical weight loss tips. However, a coach isn’t necessary to succeed on the diet.

Fullness:

Nutrition experts emphasize the importance of satiety, the satisfied feeling that you’ve had enough. Hunger shouldn’t be a problem on this diet. The Zone diet requires strategic snacking—in fact, you’ll never go more than five hours without eating. That will keep your blood sugar from dropping and hunger pangs from striking, according to Sears.

Taste:

Tasty. Recipes range from blueberry pancakes to pork medallions; snacks include cheese, wine, and peanuts. And you don’t have to give up your favorites. Occasional splurging is OK, as long as you get back on track the next day.

How much does it cost?

Online membership is free. A week’s supply of Zone 1-2-3 foods, like buns and pasta, costs about $70. A Week in the Zone, which will guide you through the diet, is $7.99.

Does the diet allow for restrictions and preferences?

Most people can customize the Zone diet to fit their needs—pick a preference for more information.

The diet’s emphasis on fruits and vegetables makes it easy for vegetarians and vegans to comply. Sears’ The Soy Zone ($16) teaches you how to build the diet around soy-based meals, like baked golden tofu dumplings, red bean chili, tofu-eggplant gumbo, and banana berry sundaes. Soy is one of the best and most versatile meatless sources of protein, according to the book.

People who can’t tolerate gluten, a protein found in wheat, barley, and rye, should have no trouble following the diet.

No recipes are specifically marked as low-sodium. But because the diet emphasizes fresh ingredients rather than salty processed foods, meeting government recommendations is doable.

Yes, you can make sure your diet is kosher.

Yes, but it’s up to you to ensure your food conforms.

What is the role of exercise?

Encouraged, but not required. Exercise is more important for weight maintenance, rather than weight loss, Sears says, a contention the mainstream medical community may not agree with. Whether for general health or weight loss, most experts recommend getting at least 2 ½ hours of moderate-intensity activity (like brisk walking) each week, along with a couple days of muscle-strengthening activities. No matter the diet, the more you move, the quicker you’ll see the pounds come off—and you’ll reduce your risk of developing diabetes, heart problems, and other chronic diseases.


Last updated by Angela Haupt | December 06, 2013

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