These Are the Best and Worst Diets of 2021

We took a look at the latest rankings from U.S. News & World Report to see which diets ranked at the top and bottom of their lists.

Every year in January, U.S. News & World Report comes out with their list of the best diets, ranked by experts and divided into categories like best overall diet, best for heart health and best for weight loss.

Now in its eleventh year, U.S. News & World Report ranked 39 diets to help people make more informed decisions about what they're going to eat. This year, they reviewed four new diets: Noom Diet, the AIP Diet, GAPS Diet and Modified Keto Diet. Nutritionists and experts in diabetes, heart health and weight loss reviewed the diets by looking at how easy they were to follow, how likely it was people would lose weight—both long and short term, safety and how the diets helped protect against chronic conditions like heart disease and diabetes.

Regardless of how these diets rank, the way of eating that may make you feel best may be different. Diet is personal and at EatingWell we encourage everyone to eat delicious food that helps them feel good, rather than follow restrictive eating patterns.

Hopefully, this list of top ranked diets can help you make better decisions about what to eat in 2021—or at least what to skip. Without further ado, here's the best and worst diets for 2021.

The top diet of 2021

For the fourth year in a row, the Mediterranean Diet ranks supreme! Of the nine categories of diets, Mediterranean tops the list of six of them. It was ranked number one for Best Diet for Healthy Eating, Easiest Diet to Follow, Best Diet for Diabetes, Best Heart-Healthy Diet and Best Plant-Based Diet, along with the Best Diet Overall.


The Mediterranean Diet doesn't have one strict definition, but it's a way of eating that includes lots of whole grains, fruits, vegetables, olive oil, healthy proteins (think more fish, legumes and nuts and less meat) and a little bit of red wine. Here are some tips for starting to eat a Mediterranean Diet (pantry list included!). There are lots of health benefits to eating Mediterranean—it's linked to a healthier heart and brain—and you get to still enjoy lots of delicious foods. Carbs and fats are plentiful, but the best kinds, so the diet is full of flavor. While some foods are limited, added sugars and meats, every food is allowed on this diet so it shouldn't feel restrictive. Even though it's called a diet, it's more of a way of eating rather than a strict diet. You can eat so many different foods including pasta, soup (like the Mediterranean Cabbage Soup, pictured above), fish, pizza, eggs and so much more.

Rounding out the top 3 best overall diet list are:

2. The Flexitarian Diet:Think of this as plant-based eating for people who aren't ready to commit to a full vegetarian or vegan diet. All the health benefits, without all the restrictions.

3. DASH Diet: DASH stands for Dietary Approaches to Stop Hypertension. It sounds fancy, but it's really a simple diet that focused on lots of vegetables and fruits, whole grains, healthy fats and proteins and reduces processed foods and too much added salt. Try our 7-Day Dash Diet Meal Plan.

The worst diets of 2021, according to experts

The 3 diets at the bottom of the list are:

37. Ketogenic Diet

38. GAPS Diet

39. Dukan Diet

These three diets were voted too restrictive and unsustainable long term. They all cut out entire food groups (see everything you can and can't eat on the keto diet), which means it's harder to get all the nutrients you need. The ketogenic diet is still popular—probably because it ranks high in the fast weight-loss diet category, even though it's not considered particularly healthy overall. While it's true you'll probably lose weight on one of these diets, they won't be the ones keeping you healthy and nourished year after year.

All the best diet categories and winners

  • Best Diet Overall: Mediterranean Diet.
  • Best Weight-Loss Diet: WW (Weight Watchers)
  • Best Fast Weight-Loss Diet: HMR Diet
  • Best Diet for Healthy Eating: Mediterranean Diet
  • Easiest Diet to Follow: Mediterranean Diet
  • Best Diet for Diabetes: Mediterranean Diet
  • Best Heart-Healthy Diet: Mediterranean Diet
  • Best Commercial Diet: WW (Weight Watchers)
  • Best Plant-Based Diet: Mediterranean Diet

So, which diet should you follow this January?

All the top diets have a few things in common. They're flexible (meaning no huge list of foods you can't eat), they focus on whole foods like fruits and vegetables and have you reduce your processed foods and added sugars.

Even if you don't jump on the Mediterranean Diet bandwagon, you can still adopt a lot of the healthy-eating principles of the diet (try these 8 ways to improve your health from the Mediterranean Diet).

As the January excitement wears off, hopefully you've picked a plan that you can stick with—one that includes all your favorite foods, but maybe a few more vegetables too.

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