The South Beach Diet

Claim: Switching to "good carbohydrates" stops insulin resistance and eliminates cravings, resulting in weight loss. Eating "good fats" prevents hunger, without increasing risk of heart disease.

Allowed Foods: Seafood, lean meats, low-fat cheese, most veggies, nuts, oils (later); whole grains, most fruits, low-fat milk or yogurt, beans Restricted Foods: Fatty meats, full-fat cheese, refined grains, sweets, juice, potatoes

PROS: Healthier version of the Atkins diet; backed by solid evidence on relationship between fats and heart disease; diet contains mostly healthy foods.

CONS: Initial phases restrict carbohydrates, which could be a problem for active people; Claims you won't ever be hungry (despite menus that average about 1200 calories per day).

The Ultimate Weight Loss (Dr. Phil's)

Claim: Foods that take time to prepare and chew promote weight loss; Emphasizes behavioral strategies for success, including a "no-fail environment", "right thinking", "healing feelings" and "circle of support".

Allowed Foods: Seafood, poultry, meat, low-fat dairy, whole grains, most veggies, fruits, (limited) oils Restricted Foods: Fatty meats, sweets, refined grains, full-fat dairy, microwaveable entrees, fried foods

PROS: Diet contains mostly healthy foods.

CONS: Based more on Dr. Phil's opinions than on science; Gives no menus, recipes or advice on portions; Recommends purchase of expensive supplements, bars and shakes that have no proven effectiveness for weight loss.

Dr. Atkin's New Diet Revolution

Claim: A low carbohydrate diet is the key to weight loss (and good health) because carbohydrates promote high insulin levels

Allowed Foods: Seafood, poultry, meat, eggs, cheese, salad veggies, oils, butter, cream; (later) limited amounts of nuts, fruits, wine, beans, veggies, whole grains Restricted Foods: Sweets, refined grains, milk, yogurt

PROS: Recent small studies have shown that the Atkins diet produced more weight loss than a typical diet after 6 months (but not after 12-months)

CONS: Overstates the results of weak studies on low-carb diets; promotes purchase of expensive "low-carb" food products; Long-term health safety not established; Too much red meat may raise risk of colon or prostate cancer; Lack of fiber, fruits and vegetables may increase risk of heart disease, stroke, cancer, diverticulosis and constipation