A decade ago, if you wanted to lose weight, you looked for any product labeled "fat-free." But these days--if you believe popular diet gurus--fat is our friend and carbs like bread and potatoes are the real villains.
To help you sort through the latest weight-loss trends, we evaluated five of today's most popular diets. But even before you check out our guide, remember this: Just about any diet will help you shed pounds in the first few weeks. It's keeping the weight off for the rest of your life that's the challenge. "Fad diets are fine for most healthy people who want immediate results," says Rovenia Brock, Ph.D., nutritionist and author of Dr. Ro's Ten Secrets to Livin' Healthy (Bantam). "But to keep the weight off over the long term, you have to watch you r portion sizes and incorporate a wide variety of foods into your diet." Check with your doctor before beginning any diet program, especially if you have health problems or are pregnant or nursing.
THE ATKINS DIET
What's the deal? Millions of Americans have traded in pasta for pork rinds on the high-protein, high-fat, low-carbohydrate diet that was created by the late Robert Atkins, M.D., in 1973. Atkins started with a simple concept: Because you get energy from either fats or carbohydrates, severely restricting carbs from your diet will force your body into ketosis, the state in which it starts burning fat for fuel. As the fat gets burned, the weight comes off.
What can you eat? In phase one, which lasts anywhere from two weeks to six months, you eliminate almost all carbohydrates except for a few helpings of salad greens, broccoli and zucchini. This means no bread, pasta, rice, baked goods--or fruit. You are, however, allowed to eat as much red meat, poultry, fish and fatty foods, like heavy cream, as you want. The only fats Atkins considers bad are trans fats, found in processed foods and commercially baked sweets like donuts. Once you've lost enough weight to begin the ongoing phase (usually after two weeks), you gradually add back into your diet small servings of nutrient-dense carbs, like a quarter cup of blueberries, until you discover the maximum number of carbs you can eat while still losing weight. When you finally reach your goal weight you're allowed whole grains, and you can even splurge on the occasional cookie or piece of cake, as long as you stay beneath your carb threshold. Atkins dieters are advised to take daily multivitamin and mineral supplements.
The pros: The Atkins plan is effective--at least in the short term. A recent study found that low-carb diets result in slightly greater weight loss after six months than a more traditional low-calorie, low-fat diet. And since countless companies have jumped on the low-carb bandwagon, with products such as Iow-carb pancake mixes and breads, it's getting easier to stick to the plan.
The cons: The weight won't necessarily keep coming off. After 12 months, Iow-carb and low-calorie dieters lost the same amount of weight, indicating that the Atkins-style dieters' loss had leveled off or they had regained some of the weight. But it's the long-term health effects of such a high-fat diet that really concern nutritionists. By eliminating so many fruits and vegetables from your diet, you're missing out on important nutrients that come from whole foods rather than supplements, says Brock. In addition, the lack of fiber in the Atkins diet may affect colon health and cause constipation, and the National Kidney Foundation warns that a low-carb, high-protein diet may increase the risk of kidney stones and bone loss. The American Heart Association is concerned about the plan's high dose of saturated fat, which clogs arteries and can lead to heart attacks and strokes. Recent studies have not found a link between higher cholesterol or heart disease and Atkins-style diets, but those studies were short-term and looked at only a small sampling of people.
THE SOUTH BEACH DIET
What's the deal? Think of the South Beach diet--created by Florida cardiologist Arthur Agatston, M.D.--as "Atkins lite." The main difference between the two? Instead of lumping all fats together, South Beach shuns saturated fats (found in red meat and butter and permitted in Atkins) in favor of monounsaturated fats like olive oil. The South Beach plan is also more liberal about carbs, allowing you to eat "good" carbs, which take longer to digest and are more filling, and restricting "bad" carbs, which send your blood sugar sky-high, making you crave even more (see sidebar "Why Am I So Hungry?"). Agatston rates foods according to the glycemic index, which measures how much certain foods increase your blood sugar compared with a similar quantity of white bread. For example, a baked sweet potato rates a 63, while a baked white potato scores a 158. Other high-fiber low-glycemic carbs include asparagus, peanuts and peppers. Agatston recommends taking a multivitamin daily.
What can you eat? As with Atkins, during the strict two-week induction phase, you abstain from pasta, bread, rice, potatoes, fruit, sugar and alcohol. After that you choose the good (high-fiber, low-glycemic) carbs over the bad, says Agatston.
The pros: If you're tempted to try a low-carb diet, this one provides a healthier range of foods than Atkins. "I think South Beach is definitely an improvement over Atkins," agrees Brock. The diet trains you to make intelligent food choices, so you'll learn important lessons in nutrition even if you go off it. And the book includes many easy-to-follow, tempting recipes.
The cons: As with any diet, losing weight is easy, keeping it off more difficult, warns Alice H. Lichenstein, D.Sc., of Tufts University. "Most people will go from one diet to another without making changes they can sustain," she says.
THE ZONE
What's the deal? "Think of food as a powerful but tasty drug that you take at least three times a day," says Barry Sears, the creator of The Zone diet. By combining a precise percentage of fats, carbohydrates and proteins in every meal and every snack, Sears claims you can stabilize your blood-sugar levels, which will cure your cravings. This will help you lose weight, live longer and perform at your peak mental state, he says.
What can you eat? In this diet, almost everything is allowed--as long as the snack or meal follows the magic formula of 30 percent monounsaturated fat, 30 percent lean protein and 40 percent complex carbohydrate, and stays within the limit of 500 calories per meal and 100 calories per snack. "At each meal you divide your plate into three equal sections," explains Seam. "On one third of the plate put some low-fat protein, like white-meat chicken or fish, that is no bigger and thicker than the palm of your hand. Fill the other two thirds to overflowing with fruits and vegetables, and then add a dash of monounsaturated fats, such as slivered almonds or guacamole." Foods that are restricted include egg yolks, fatty meats, potatoes and corn.
The pros: No single food group is eliminated on this diet, so it is more likely that you will be getting all your nutrients without having to take supplements. And if you can stay on it, you will certainly lose weight, admits Brock, since the calorie count per day remains very low.
The cons: You practically need a Ph.D. to stick with The Zone, because everything you put in your mouth should fit the 30/30/40 formula. "Constant micromanaging is a real turn-off; no one wants to be that meticulous forever," says registered dietitian Keith Ayoob, Ed.D., a spokesperson for the American Dietetic Association. Several companies across the country will deliver Zone-ready gourmet meals and snacks to your doorstep so you don't have to do the math or preparation yourself. But at around $30 a day, convenience doesn't come cheap.
DEAN ORNISH DIET
What's the deal? In the 1990's, before "low-carb" became a weight-loss mantra, the low-fat diet prescribed by Dr. Dean Ornish was all the rage. "Fat has nine calories per gram, and proteins and carbohydrates have only four. So if you eat less fat, you reduce the number of calories you consume even if you eat the same amount of food," Ornish explains. He believes a healthy diet for weight loss has lots of fruits, vegetables, legumes and grains. The optimal diet would exclude meat and other animal products. Ornish also advises you to skip simple carbohydrates like white flour, white sugar and alcohol, which lack fiber and don't fill you up as much as complex carbohydrates like whole grains, fruits and vegetables.
What can you eat? Oils and fatty meats are no-no's, while poultry, veal, rice, potatoes and sugar are restricted. You don't have to be a vegetarian to stick to the Ornish diet, but it helps, since he stresses the importance of low-fat, nutrient-dense beans, legumes and vegetables. A typical dinner might include fillet of sole, red beans and dirty rice, a green salad, grilled asparagus, and fruit for dessert.
