For the third year in a row, the well-researched Mediterranean diet KO'd the competition to win gold in US News and World Report's 2020 ranking of best diets . The report, released Thursday, is now in its 10th year.

"The hallmarks of a 'best' diet include balance, maintainability, palatability, family-friendliness, sustainability, along with healthfulness. The Mediterranean diet gets checkmarks in all of those boxes," said Yale University Prevention Research Center founding director Dr. David Katz, who was one of 25 judges on the U.S. News and World Report panel.

"It's no surprise that the Mediterranean diet remains the No. 1 best diet overall," said nutritionist Lisa Drayer, a CNN contributor. "It's easy to follow and offers a healthy eating lifestyle. "

The diet focuses on eating less red meat, sugar and saturated fat and more Omega-3-rich fish and olive oil. Red wine can be enjoyed in moderation and socializing with friends and family during meals is part of the prescription.

Photos: Delicious Mediterranean diet foods The Mediterranean diet is easy to find in the grocery store, contains nutrients that are known to enhance longevity and has other health benefits that are backed by peer-reviewed, scientific studies. Broccoli makes the list because it's one of nature's most nutrient-dense foods, with only 30 calories per cup. That means you get a ton of hunger-curbing fiber and polyphenols -- antioxidants that detoxify cell-damaging chemicals in your body -- with each serving. Hide Caption 1 of 12 Photos: Delicious Mediterranean diet foods Doctors suggest using olive oil rather than butter to make your meals. A Spanish study found a Mediterranean diet supplemented with extra-virgin olive oil reduced the incidence of major cardiovascular events among patients with a history of heart disease. Hide Caption 2 of 12 Photos: Delicious Mediterranean diet foods Quinoa is the popular whole-grain du jour because it also contains a good dose of protein to help build muscle. Yet including any type of whole grain in your diet -- from barley to brown rice -- will aid in weight loss by filling you up for fewer calories. Hide Caption 3 of 12 Photos: Delicious Mediterranean diet foods Blueberries are often singled out as a kind of superfood because studies have shown they aid in everything from fighting cancer to lowering cholesterol. But all berries, including raspberries, strawberries and blackberries, contain antioxidants and phytonutrients . Worried about the price of fresh fruit? Experts say the frozen kind is just fine. Hide Caption 4 of 12 Photos: Delicious Mediterranean diet foods Many dieters shy away from nuts because of their high calorie and fat count. But studies show that eating a handful several times a week can prevent heart disease and ultimately help you shed pounds since they fill you up and stop you from snacking on other things. Almonds, in particular, contain lots of monounsaturated fats and fiber. (Healthy swap: Replace peanut butter with almond butter.) Hide Caption 5 of 12 Photos: Delicious Mediterranean diet foods Salmon is also a good source of lean protein. With this diet, doctors suggest eating fish at least two times a week. Salmon provides a high dose of omega-3 fatty acids, which studies show significantly lower the risk of heart disease. Omega-3 fatty acids fight back by reducing inflammation and slowing the rate of plaque buildup in blood vessels. Hide Caption 6 of 12 Photos: Delicious Mediterranean diet foods Beans, beans, the magical fruit; the more you eat, the more ... you lose weight. Black, kidney, white and garbanzo beans (also known as chickpeas) are good for fiber and protein. They fill you up and provide muscle-building material without any of the fat that meat can add to your meal. Hide Caption 7 of 12 Photos: Delicious Mediterranean diet foods Eating a breakfast high in protein is a good way to keep hunger at bay throughout the day. Eggs are full of choline, a nutrient that helps block fat from being absorbed in the liver. Choline may also help in preventing memory loss. Hide Caption 8 of 12 Photos: Delicious Mediterranean diet foods Spinach is a great source of iron, which is a key component in red blood cells that fuel our muscles with oxygen for energy. But researchers in Sweden identified another way in which these greens might keep you charged: Compounds found in spinach actually increase the efficiency of our mitochondria , the energy-producing factories inside our cells. That means eating a cup of cooked spinach a day may give you more lasting power on the elliptical machine (or in your daily sprint to catch the bus). Hide Caption 9 of 12 Photos: Delicious Mediterranean diet foods Walnuts are packed with tryptophan, an amino acid your body needs to create the feel-great chemical serotonin. (In fact, Spanish researchers found that walnut eaters have higher levels of this natural mood-regulator.) Another perk: "They're digested slowly," said Dr. David Katz, director of the Yale Prevention Research Center. "This contributes to mood stability and can help you tolerate stress." Hide Caption 10 of 12 Photos: Delicious Mediterranean diet foods Asparagus is one of the best veggie sources of folate, a B vitamin that could help keep you out of a mental slump. "Folate is important for the synthesis of the neurotransmitters dopamine, serotonin and norepinephrine," said David Mischoulon, associate professor of psychiatry at Harvard Medical School. All of these are crucial for mood. Hide Caption 11 of 12 Photos: Delicious Mediterranean diet foods It's not a requirement to drink it on this diet, but if you do drink alcohol, red wine in moderate amounts can be good for your health. Moderation means one drink for women and two for men, by the way. Studies show red wine can help protect against heart disease. Hide Caption 12 of 12

Top honors

Following closely behind the Mediterranean diet were the respected DASH, Flexitarian, WW (the rebranded name popularly known as Weight Watchers) and MIND diets. Their high rankings are a trend in the report's results each year.

"We're interested in diets that have proven staying value -- not fad diets that are here today, gone tomorrow," said Angela Haupt, managing editor of health at U.S. News & World Report. "The diets that perform well are safe, sensible and backed by sound science. That's going to be consistent from year to year."

The DASH diet is often recommended to lower blood pressure. Its premise is simple: Eat more veggies, fruits and low-fat dairy foods while cutting way back on any food high in saturated fat, and limit your intake of salt.

Studies have shown following this diet can reduce blood pressure in a matter of weeks.

The flexitarian diet tied with the DASH diet for second place because of its emphasis on whole grains, fruits, veggies and plant-based proteins. It's basically a vegetarian diet that allows the occasional piece of meat or fish, thus making it "flexible."

The MIND diet is a combination of the Mediterranean and DASH diets that some may find a bit easier to follow, as it requires less fish and fruit. Both MIND, which stands for "Mediterranean-DASH Intervention for Neurodegenerative Delay," and the Mediterranean diet have been shown to lower the risk of Alzheimer's disease in studies

WW came in fourth on the best diet list but took first place in the report's ranking of best weight loss and commercial weight loss programs. Not only is the diet healthy, the panel said, but it wins top points for stressing the importance of support for dieters.

Speaking of the keto craze ...

Down for the count

Sure to upset its legions of fans, the trendy keto diet came in next to last in the ranking of 35 diets, just ahead of the obscure Dukan diet.

Both diets aim for "ketosis," a metabolic state that burns the body's stores of fat instead of carbohydrates, the body's natural source of energy. To do that, the diets restrict carb intake to levels nutritionists feel are highly unhealthy as well as completely unsustainable.

In the keto diet, Drayer said, "carbs are limited to about 20 grams per day," the equivalent of one small banana or apple. Due to the drastic cut in carbs, the diet can cause "headaches, nausea, dizziness and fatigue, particularly in the beginning," she said, adding that "long-term studies on its effectiveness are lacking."

In place of carbs, the keto diet emphasizes high levels of protein, fats and dairy, typically full of saturated fat that can contribute to cardiovascular and other chronic diseases.

"I am not a fan of the keto diet, though it may be helpful as a 'jump start' to weight loss and can help you quickly rid your diet of processed carbs and sugars," Drayer said.

Which may be why the keto diet tied for third place in the race for best "fast" weight loss diet.

'Fast' weight loss?

First place in the get-rid-of-fat-quick category went to HMR, the Health Management Resources program . It involves purchasing meal replacements from HMR, such as shakes, nutrition bars and multigrain cereals, and adding vegetables and fruits to round out the meals.

Second place went to Optavia, which used to be called Medifast. It, too, wants you to buy and eat many of the company's pre-packaged products, supplemented by some foods at home.

Both diets could be difficult to follow, Haupt said, "because prepackaged meals tend to get old fast."

The highly ranked WW tied for third, along with Jenny Craig , which ranked 12th in the best overall diet list.

But the low/no-carb diet Atkins and the keto diet also tied for third place, despite ranking in the deep bottom of other diet categories, such as best diet, most healthy diet and best diets for heart health and diabetes. Ironically, HMR and Optavia joined them toward the bottom of the other categories.

Why would diets that are considered good at helping drop weight quickly be ranked so badly overall?

"The 'best' way to lose weight fast is to do something very silly, unsustainable and arguably irresponsible. It's not truly best -- just fast," said Katz, who is the president of the True Health Initiative , a non-profit organization dedicated to health promotion and disease prevention

"Many things that are truly bad for health can cause short-term weight loss," Katz said. "The most effective diets for 'fast' weight loss impose severe restrictions that cannot be maintained and would not be compatible with health if they were."

That's because quick weight loss diets usually emphasize some drastic cut in nutrients or the elimination of an entire food group that can't be maintained over time. When the diet stops, the weight comes back, often at higher levels than at the start of the diet. It's the body's response to "yo-yo" dieting, studies show

"Spending your life weight-obsessed, and going on and off diets, is no way to live," Katz said. "One of the things we hope to convey to the American public is that it's time to grow up about diet and give it more respect.

"Grown-ups don't generally expect to 'get rich fast;' they understand the need to work, over time," Katz continued. "But everyone thinks there is some magic formula they haven't tried yet for rapid weight loss. The consensus of the U.S. News judges is a resounding rebuke of that silly idea."