Two new low-carb diets are all the buzz among people trying to lose weight, but how well do they stack up with nutritionists? We asked weight-loss experts to weigh in:
The 17-Day Diet
One strict new diet that promises fast results is The 17 Day Diet: A Doctor's Plan Designed for Rapid Results by Mike Moreno, a physician in San Diego, is No. 8 on USA TODAY's Best-Selling Books List.
The diet starts with the accelerate cycle, which includes lean protein, "cleansing vegetables" such as broccoli and cabbage, and low-sugar fruits such as berries and apples, healthy fats (olive oil, flaxseed oil), low-fat yogurt, water and green tea.
It eliminates many foods, including most fast foods, fried foods, processed foods, starchy carbohydrates such as bagels, pasta, sugary cereals, crackers and white bread, and fruits such as pineapple, watermelon and bananas.
"Most people can expect to lose 10 to 15 pounds during the first 17 days," the book says.
In the second cycle, the dieter alternates high-calorie and low-calorie days to create "metabolic confusion," Moreno says. It includes some starchy foods such as corn and potatoes. The third cycle reintroduces other foods rich in carbohydrates, and the final cycle allows dieters to eat nearly anything in moderation.
Dawn Jackson Blatner, a registered dietitian in Chicago, says people will lose weight on this diet because it's low in calories, not because of "metabolic confusion."
She says most of the book's advice is nutritionally sound, including the emphasis on consuming lean protein, veggies, fruit, low-fat yogurt, whole grains, healthy fats, water and green tea - and exercising.
However, she doesn't agree with the author's recommendations to avoid certain fruits and vegetables at the beginning of the program. "Whenever parts of a plan have you limit healthy produce, that should be a red flag it's not nutritionally balanced."
The Dukan Diet
Among the latest news reports about the royal wedding are rumblings about a new diet that's being imported from France.
Kate Middleton's mom, Carole, has reportedly been following a high-protein weight-loss plan called the Dukan diet created by a French doctor.
A book on the plan, The Dukan Diet by Pierre Dukan, is being released Tuesday in the USA.
The four-phase program starts with the attack phase, in which people eat only lean protein foods such as filet mignon, extra lean ham, veal chops, chicken, turkey, salmon and swordfish, eggs, non-fat dairy and tofu. This part lasts two to seven days.
Next comes the cruise phase, in which dieters alternate pure protein days with protein-and-vegetables days; then the consolidation phase, which allows for two celebration meals a week; and finally the stabilization phase in which dieters eat only protein one day a week for the rest of their lives. The book includes Dukan's list of "100 natural foods that keep you slim" and recipes and menus.
Dukan told USA TODAY that people like his plan because "it's simple and easy to understand. You can eat as much as you want of the 100 allowed foods."
Some U.S. nutritionists say they wish the plan had stayed on the other side of the pond.
"This is yet another high-protein, unbalanced rigid regimen," says Bonnie Taub-Dix, a registered dietitian in New York\and a nutrition blogger for food.usatoday.com. "I wish that high-profile celebrities and dignitaries would realize how important they are as role models."
People will lose weight on the Dukan diet because it drastically reduces calories, but when you restrict healthy foods such as vegetables, fruit and whole grains, there are side effects such as fatigue, dry mouth, constipation and bad breath, says Jackson Blatner, a nutrition blogger on food.usatoday.com. "In fact, negative diet side effects should be a red flag that this isn't healthy."
Mireille Guiliano, author of the best-selling French Women Don't Get Fat, says the Dukan method "is very controversial in France" because the program is "highly unbalanced and restrictive."