These Are the Best Diets of 2021, Says U.S. News & World Report

These Are the Best Diets of 2021, Says U.S. News & World Report

The GAPS, Keto and Dukan diets landed at the bottom of the annual list. How did your diet fare?

With the arrival of the new year, Americans in large numbers are gearing up to take better care of themselves; focusing on wellness may be on your own list of resolutions. And for many—even during the COVID-19 pandemic—that means adopting some sort of diet.

To kick things off, U.S. News & World Report has released the Best Diets 2021 rankings, its 11th annual assessment of popular diet plans. In compiling this year’s list, U.S. News editors and reporters scoured medical journals, government reports and other health resources. Their thorough analysis identified 39 diets to be included in the rankings. The researchers then created profiles for each diet that included whether or not it helps to achieve the specific goal, if there are any risks involved and what it’s like to actually live on the diet.

Next, a panel of nutritionists, researchers and physicians specializing in diabetes, nutrition, obesity, food psychology and heart health reviewed the profiles, added their own facts and research and scored each diet across seven categories, including:

  • How easy it is to follow
  • Short- and long-term weight loss results
  • Nutritional completeness
  • Safety
  • Potential for preventing or controlling diabetes and heart disease

The popular plant-based Mediterranean Diet ranked highest, taking the top spot as best overall diet. Trailing closely behind is the heart-healthy DASH Diet, tied with the veggie-rich Flexitarian Diet.

The Gut and Psychology Syndrome (GAPS), Keto and Dukan diets came in at the bottom of the rankings, with Dukan ranking last. The reasons? First, the diets are very restrictive. Moreover, the Dukan Diet—which involves strict rules and multiple phases—has experts concerned about its nutritional completeness, its safety and its ability to control diabetes and heart disease. One U.S. News expert even called the diet “idiotic.” Bottom line? There’s just not enough evidence to prove it actually helps you lose weight or helps prevent chronic diseases.

Whether you’re looking to lose weight, consume less meat or eat clean, here’s a breakdown of this year’s diets and how they stack up against one another.

A closer look at the top 3
For the fourth year in a row, the Mediterranean Diet ranks at the top of the list. A mounting pile of evidence suggests this heart-healthy diet can help you shed unwanted pounds, boost brain health and help protect against cancer and diabetes. A Mediterranean Diet focuses on fruits and vegetables, whole grains, legumes, beans, nuts and olive oil. Seafood is encouraged at least twice a week, and eggs and poultry may be consumed occasionally, in moderation. An occasional glass of red wine is fine, but added sugars, red meat and other sources of saturated fats are limited.

Coming in second overall is the DASH Diet, the heart-friendly eating plan that aims to lower blood pressure, raise levels of “good” cholesterol (HDL), lower “bad” cholesterol (LDL) and help you control your blood sugar. The DASH Diet also emphasizes whole grains and fruits and vegetables, but unlike the Mediterranean Diet, it outlines specific servings of each food group. Foods high in potassium, magnesium, fiber and lean proteins are encouraged. The diet also suggests limiting foods that can hurt your heart, like salt, sweets and red meat.

The mostly plant-based Flexitarian Diet is tied for second place. Rather than eliminating meat altogether, the goal of being “flexitarian” is to pack your plate with whole grains, legumes, fruits, veggies and nuts. It's a diet that’s been proven to help people lose weight and lower their risk of heart disease, diabetes and cancer. While the occasional serving of meat is fine, sticking to mostly plant-based foods is ideal. U.S. News ranked a Flexitarian Diet above a Vegetarian Diet largely because it’s easier to stick to.

Other best diets by category
In addition to the best diets overall, U.S. News also ranked the best diets for several different categories. These included certain health conditions, like diabetes, as well as particular goals, like weight loss. Here’s a breakdown of the top three for some of the most popular categories.

Best commercial diets: Well-known diets like Weight Watchers are popular because they are convenient and often offer prepared foods or supplements. Experts ranked 15 structured programs that involve a participation fee or promotion of the company’s product.

1. Weight Watchers
2. Mayo Clinic Diet
3. Jenny Craig Diet (tie)
3. Noom (tie)

Best weight-loss diets: Some diets aim to help you drop pounds fast, while others help you shed weight slowly and steadily. Experts took both short- and long-term weight loss ratings into consideration when they created the final list.

1. Weight Watchers (tie)
1. The Flexitarian Diet (tie)
3. Vegan Diet (tie)
3. Volumetrics (tie)

Easiest diets to follow: You’re probably more likely to stick to a diet if it’s fairly easy to follow. Experts rated these diets on taste, restrictiveness and overall satisfaction.

1. Mediterranean Diet
2. Weight Watchers
3. Flexitarian Diet

Best diets for diabetes: A healthy diet is one of the best ways to help control diabetes; these diets were rated based on their ability to prevent and manage the condition.

1. Flexitarian Diet (tie)
1. Mediterranean Diet (tie)
3. DASH Diet (tie)
3. Mayo Clinic Diet (tie)
3. Vegan Diet (tie)

Best heart-healthy diets: Being overweight or obese is a significant risk factor for heart disease and stroke. These diets aim to help you lose weight, lower your cholesterol levels and reduce blood pressure.

1. DASH Diet (tie)
1. Mediterranean Diet (tie)
1. Ornish Diet (tie)

Best plant-based diets: Plant-based diets are gaining popularity—and for good reason. Following these diets helps the environment, your heart and your weight loss efforts.

1. Mediterranean Diet
2. Flexitarian Diet
3. Nordic Diet (tie)
3. Ornish Diet (tie)
3. Vegetarian Diet (tie)

Before you start a new diet, it’s best to talk with your doctor. Your current weight, prior medical conditions and lifestyle habits all play a role in determining what’s best for you. Read more about U.S. News & World Report’s rankings of all 39 diets.

Medically reviewed in January 2019. Updated in January 2021.


U.S. News & World Report. “Best Diets Rankings.” January 2021.

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