Thanks to its flexibility, easy-to-understand system, and group support, Weight Watchers came out way (weigh?) ahead, winning "best weight loss," "best fast weight loss," and "best commercial diet" in the U.S. News & World Report rankings. (Oprah's endorsement probably didn't hurt either!) They recently revamped their signature plan to include "free" foods like chicken breasts and fresh produce so you'll never feel hungry even while dropping pounds. In addition, their app makes tracking your food a piece of cake—which you're totally allowed to have on the program, by the way. (Even better news: Research supports the fact that Weight Watchers is one of the best weight-loss diets.)
What the expert says: ‘There is a large amount of evidence to suggest that following the MD reduces your risk of cardiovascular disease,’ says registered Dietitian and British Dietetic Association spokesperson Kirsty Barrett. ‘Significantly, a meta-analysis of randomised-control trials in 2011 found that the MD was effective for weight loss, though results were better when the diet was combined with energy restriction and physical activity. It has also been found to reduce LDL (bad cholesterol) more than low fat and low carb diets.’
"Even though it's called the Mediterranean diet, it's not really a diet," said Atlanta registered dietitian Rahaf Al Bochi, a spokeswoman for the Academy of Nutrition and Dietetics. "It doesn't tell you what to eat and not eat. It's a lifestyle that encourages consuming all food groups but gives more weight to those which have the most health benefits."
You can certainly still eat red meat once in a while, but choose leaner cuts. Lamb is often the red meat of choice in Greece and other Mediterranean countries. You might like to try: Kofta Kebobs; Grilled Lamb Chops with Mint Quinoa; or Moussaka (Greek eggplant and lamb casserole). For special occasions, I highly recommend Leg of Lamb with Potatoes.
In this meta-analysis, the researchers looked at the results from a total of 20 randomized controlled trials with more than 3,000 subjects, most of whom had type 2 diabetes.  Although the authors concluded that low-carbohydrate, low-GI, Mediterranean, and high-protein diets should all be considered as a dietary strategy for diabetes management, the low-carb diet proved itself as being superior in 6 of the 8 studies.
Switch to Lighter Alternatives. Whenever you can, use the low-fat versions of salad dressings, mayonnaise, dairy products, and other products. "You can trim calories effortlessly if you use low-fat and lighter products, and if the product is mixed in with other ingredients, no one will ever notice," says Magee. More smart substitutions: Use salsa or hummus as a dip; spread sandwiches with mustard instead of mayo; eat plain roasted sweet potatoes instead of loaded white potatoes; use skim milk instead of cream in your coffee; hold the cheese on sandwiches; and use a little vinaigrette on your salad instead of piling on the creamy dressing.