Fad or Fact? by Deborah Southard ImagineYourHealth puts three popular diets under the microscope print article      send to a friend

Walk the "Diet & Nutrition" aisle of any bookstore and you'll be accosted by authors trying to convince you that you can lose weight with their plan.  Infomercials suck you in with claims like, "It's revolutionary!" or "Lose ten pounds in just ten days with our new weight loss system!"  Awash in an ocean of conflicting information, you're worried that you'll drown. 

Never fear.  We've decided to kick confusion out the door.  We chose three popular diets, stripped away the hype, and gave you just the facts.  Here's our look at the Atkins diet, The Zone, and the Ornish diet.

The man behind the plan is Robert Atkins, MD.  Following this plan, the dieter cuts all carbohydrates; as long as it's not a carb, you can eat it (yes, that means you could guzzle lard if you were so inclined). 

You'll begin losing weight immediately, although it will be mostly water.  The theory behind the diet is that by cutting out carbohydrates your body will be forced into a state of ketosis (an abnormal increase in the production of ketone bodies).  The body will begin using excess body fat for fuel, essentially feeding on itself.  This can be extremely dangerous in the long-term; it can lead to internal organ damage, especially to the kidneys. 

The eating plan is hard to swallow.  When you leave carbohydrates out, you leave a lot of foods out.  "It's a very high protein diet and it leaves out most carbohydrates and starches.  Anytime a diet does that it leaves out a food group, which means it leaves out essential vitamins and minerals.  And since it's high in protein it also tends to be high in fat," says Kimberley Tessmer, RD (Registered Dietician), of Cleveland, Ohio.  What's more, you'll eventually get bored with the limited food choices and begin to crave the carbs. 

The Zone is the brainchild of Barry Sears, Ph.D.  Sears initially developed the program as a way to combat heart disease and treat diabetes.  The diet is a balance of protein, carbohydrates, and fat in a 40-30-30 ratio.  This is a deviation from the typical American diet, which derives at least 50-60% of its energy from carbohydrates.

Weight loss on this diet comes from calorie reduction, not from "getting into the zone."  The method behind the madness involves balancing insulin and hormones called eicosanoids; the ultimate goal is to enable the body's cells to burn stored calories and prevent fat from being stored in unwanted places. 

The practicality of the meal plans is where the dieter will run into trouble.  Food preparation is quite a chore - many of the recommended foods are difficult to find and even more difficult to prepare.  "It's very difficult to follow because of the specific food regimen," notes Tessmer.  As a result, you'll feel like you're in the kitchen 24 hours a day just trying to keep in the "Zone."  There is a mail-order catalogue that offers frozen dinners, but the meals often cost three to four times the price of regular brands.  Critics of the diet say that it restricts carbohydrates unnecessarily, and that much of the science behind the program is unsubstantiated.

Details about the diet can be found in the Dr. Sears' book The Zone.  It is available at most major bookstores.

The father of the Ornish Diet is Dean Ornish, MD.  It began as a way to combat atherosclerosis or heart disease characterized by high cholesterol, and has been proven effective at reversing blockages of the heart.

The diet doesn't pay much attention to calorie reduction, but contrary to the Atkins Diet does insist upon a low-fat, high-carbohydrate program.  This means lots of fruits and vegetables and avoiding animal proteins found in dairy and meat.  "This diet encourages low-fat eating and healthy eating for the heart.  It's more realistic," Tessmer comments. Dr. Ornish also encourages daily exercise along with some sort of stress-management tool such as yoga or meditation.

Vegetarians may be the only dieters to find success with this plan.  Since the plan discourages the dieter from eating meat - whether it's chicken, fish, or beef - many Americans will have a hard time adhering to guidelines.  However, if you can adjust your eating habits and follow the plan, you will lose weight.  "If I had to pick one of these diets, it would be the Ornish Diet, because it's low-fat and good for the heart," concludes Tessmer.

The Ornish Diet is described in detail in Dr. Ornish's book Eat More, Weigh Less.

In a final note, a recent review of popular diets by the U.S. Department of Agriculture revealed that programs such as Weight Watchers and those recommended by the American Heart Association have the most scientific evidence to substantiate their claims.  The report also mentioned that there is good evidence to support the effectiveness of the Ornish Diet.